# Mini gas burner



## Blogwitch (Feb 6, 2010)

This isn't an engine build, but an add on for certain types of engines. Namely flame lickers and sterlings, which usually rely on a spirit burner for their heat source.

For over a couple of years now I have been wanting to make some mini gas burners, and I purchased the plans off Jerry Howell when he was still with us. Luckily, his family has taken over retailing Jerry's plans, and if you want to make one (or a few) of these, the plans for the burner can be purchased here.


I was talking to friend on Skype and mentioned about the burners, and he instantly piped in that he had seen an exhibitor at a show in the US running a couple of his engines with them, and when questioned about them, he said they were the best thing since sliced bread. My friend is now in the process of making one for himself after buying the jet from the above address.

I will just say that during this build, I will be taking a few pics of the plans, to explain a few things, but I will be covering up as many dimensions as I can. The cost of the plans is peanuts, and I would recommend buying them, as they also contain plans for a small pressure regulator and a safety shut off valve.

I am not able to do large articles like I once did, so this might stop and start a bit, as and when I feel I can do a little more.

So this is basically what they look like, About 3/8" diameter for the stack, and about 1.5" tall (without the base). I won't be making bases for mine as they will be incorporated into the engine itself. So I will have a stock of the burners, and make the fittings to fit when needed. The bases are only a screw on item anyway.



As you can see from the above pic, the main tube is a venturi, this is to speed up the gas coming from the jet to give an efficient burn at the top of the stack. On the notes that come with the plans, it is well explained.
The first thing I do when starting a project like this is to make up any special cutting bits that will be needed. So, as you can see, I have sketched up the d-bit forms that I will require.
I am not going into detail about d-bits as it has already been covered many times. But I will say that this sketch was modified on the run to include cutting the recess for the gauze at the top of the stack.



Five minutes on the offhand grinder with a bit of tool steel and a radius gauge had the form tool made for cutting the d-bit shape. This shot shows it doing it.



I then made the second d-bit, and then both were halved (plus a couple of thou dressing allowance) on the mill.



After hardening (I don't temper small tools such as this), and sharpening on an oil stone, this is what they look like.



A few of the stack blanks machined to length. These were spot drilled, and then relief drilled equally from each end for the d-bit guidance. This was to ensure that things stayed on the straight and narrow as the d-bits did their job.



This is the curved gas entry end.



And where the flame will be. You will notice that the d-bit has also formed the recess in the end for the stainless steel gauze diffuser to sit into. This bit needs a little more work doing on it before being finished, mainly the bore needs to have a little polishing done.



As I have already said, this has been in the pipeline for a long time now, but I am only just getting things together. These are some of the items I require for my assault on these burners. You might say that I have purchased too much, but in fact, if you can buy in bulk, it works out a lot cheaper. A good example are the o-rings. If bought individually they work out expensive. For the price of 20 from a normal supplier, I got 101 o-rings for a cheaper inclusive price from a main distributor.
I will be using 8BA thread for the jets, and those plated brass screws are what I will be working with. I have ordered some 2-56 ones from the US, but they haven't shown up yet. 
On Jerry's site, it states that the jets are in limited supply, so if things turn out well with the drilling, I might be able to give some sort of backup if ever they become scarce.



The jets do require a very fine hole in them, no compromise here, the wrong sized hole, forget it. The burner just won't work right.
I thought I would show you what one of these drills looks like. On the left is a normal 1/16th drill bit and on the right a 1/32" one.
Methinks most people won't have the facilities to run drills of this size, so I would suggest buying the jets instead. For the amount of work and facilities that are required to make them yourself in small quantities it is a no brainer exercise.
I still don't know whether I can drill them with the equipment I have, only time will tell. So I might be going to buy ones for mine.


Now a bit of a saga that sometimes things just don't go right.

I made the curved d-bit out of a little leftover stub of silver steel, and the long tapered one out of a new bar. Both were hardened by the same process at the same time. 
The little curved one cuts a dream, and all the stacks I am making were cut just fine. After cutting the first one with the tapered bit, then attempting to cut the second, the bit just twisted up. I put the bend in it, just to show that it is still soft. I had forgotten to do a file test for checking the hardness after heat treating (complacency) and I now suspect someone has slipped in a length of something that isn't water hardening silver steel when I ordered off the net. I will have to wait now until monday before I can go to my normal supplier to get something that I know will work.


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## 1hand (Feb 6, 2010)

That is the smallest drill I've ever seen. I'd be afraid to even touch it. Very interesting as are all your informative posts. Thanks for bringing us your great Ideas as they transform.

Thanks,

Matt


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## ref1ection (Feb 6, 2010)

Good to see you in the shop as I thoroughly enjoy following your posts, so much to learn from them.

Ray


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## Blogwitch (Feb 6, 2010)

Matt,

Not the smallest that are commercially available, but very close.

I bought these part used ones from the US, solid carbide, they are used for military contracts, and are changed well before they are worn out. For what I will be doing with them, they are perfect. I do have a few of my own HSS ones, they are a little more forgiving, as they can bend a little during use, whereas the carbide will break at any slight deviation.

They are not cheap by any means, but they work out at 1/6th the cost of buying new in the UK, even including mailing costs. About 4 bucks apiece in the UK. 
But if you do break them, the carbide shanks make great scribers. The only problem is, you can only use so many scribers at any one time.



Ref1ection,

As I have stated, things have changed dramatically over the last few months so I can't plan on anything, even day to day, when I can, I will, when I can't, I won't.


Blogs


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## Deanofid (Feb 6, 2010)

This is very timely, John. I ordered the prints and a jet just a day ago, and here is a new article, right on time!

I wonder if pilot light jets would work? They come in different jet sizes, of course, but they are readily available at heating and air conditioning supply houses. I may have to check in with our local heating place. I can see wanting more than one of these little burners.

Dean


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## SBWHART (Feb 7, 2010)

Hi John

I'll drop you off some 3/8 silver steel this morning.

Stew


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## Blogwitch (Feb 7, 2010)

Dean,

I can almost guarantee that jets with the same size hole are available, I know, I used to use them when making steam engine boilers and gas plants, just as I could almost guarantee you wouldn't be able to physically fit them into this burner.

Wait until you get your bits, then make the decision. Don't sneeze though, Jerry's jets are tiny.

Thanks Stew, have sent you an email.

John


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## NickG (Feb 7, 2010)

Blogs, watching this with interest. I just drilled the smallest hole I ever have in my oil cup for latest project - that was number 60, or 0.040". Did it in the harrison, usual chucks at max speed of 720rpm which it rarely gets to, had to drill about 1/4" deep - scary for me! It is double the size it's meant to be so will let a lot mroe oil through than intended! I do have a couple of smaller drills somewhere that have remained in the little plastic bag, they came in since purchase!

Nice D bits.

Nick


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## Blogwitch (Feb 7, 2010)

Nick,

If 0.040" scares you, methinks new trousers are in order when you come to drill one this size.


Dean,

Just to show you what I am on about, I have just been out to the shop and taken this shot.







The left hand one is a standard gas jet for a propane burner, and the 8BA screw is what the jets will eventually be made from. After the threads have been reduced by half in length and the head turned down a little both in diameter and thickness.

As Jerry didn't or doesn't supply the dimensions for a one piece jet to make yourself, only one for a composite build using a watch jewel for the jet orifice, I have come up with my own, which I think is very close to the ones supplied. Plus it will also have a sealing washer, most probably made from PTFE sheet.






Anyway, this is jumping the gun a bit, these items are not for making yet, but sometime in the near future, after all the other bits are made. Then maybe I can give a bit more insight into how I get on with drilling the holes.


John


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## ghart3 (Feb 7, 2010)

Something else that will work if someone doesn't have the means to drill the small hole is capillary tube.  http://www.smallparts.com/ in the states has a size that is .062" OD and .005" ID.  This is what I used when building one of Jerry's burners and it has been working OK.     gary


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## Blogwitch (Feb 7, 2010)

Very good suggestion Gary. That will sure make the build a lot easier for the people who don't have the drilling facilities.

What do you think of the burners? Do they do a good job?

Blogs


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## Noitoen (Feb 7, 2010)

I have an idea :idea: Since the jet is kept cool you could drill a bigger hole, fill it with soft solder and then drill the solder. Just an idea :hDe:


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## ghart3 (Feb 7, 2010)

John the burner works very good.  For my needs it is used only on about the smallest flame that can get.  Even with the 10-80 thread on the needle valve it is a little ticklish getting setting right.    Gary


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## Blogwitch (Feb 7, 2010)

Thanks for the info Gary. It is always good to have someone in the background who has already made one, just to point the way a little when we stray.

I don't think I have anything in my tap & die selection that will give me such a fine thread, and I don't fancy trying to machine cut one, so I will be using something in the BA range, and use the regulator to get the can pressure down some, to a more controllable level. Also the needle in the plans does look somewhat stocky, a much finer needle should give a smoother control. I have already redesigned the control valve in my head to make it easier to get it to seal better, so it is only a slight angle mod to have a much finer needle to overcome problems that people may have if they don't use a regulator in the line.

I am trying to make these into a UK version that uses the BA system, as the US UNC/UNF over here are much more difficult to obtain in the smaller sizes at reasonable cost.

The mods that I do shouldn't affect the overall build though, as people can use the threads that they are most comfortable with, and build as per plans if they do have the correct screwcutting equipment. 
If people have to go out of their way to buy specialist tooling to get a working burner, the high costs can take the edge off the overall project and make it uneconomical to have a go. Whereas if I can show how easily and cheaply the main parts are produced, I think that will be plenty good enough to give them the confidence to have a go themselves.

People shouldn't take any notice of the quantities I buy and build in. Later, when things improve for me, my workshop, again, will be turned into a small production facility, as it was until the middle of last year, so anything I have in stock will be used somewhere or other. If the plans call for one o-ring, then just buy one.

Just a note to Noitoen.

With drills of this size, I don't think that the material makes much difference. It is the feeds and speeds plus swarf clearance that controls whether the drill will break or not. I have had great trouble before now drilling small holes into Delrin, but on the other hand, I have also successfully put a 0.010" hole thru a 1/8" stainless ball bearing, with no drill breakages. Sometimes machining can come up with all sorts of little surprises you never thought would happen.

Blogs


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## Andy_B (Feb 7, 2010)

Glad you are back in the shop Blogs.

Now I can add some more to my knowledge base. ;D

Andy


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## Deanofid (Feb 7, 2010)

John, thanks for the shot for a size comparison of the jet and the small screw.
_Also_, thanks for putting the parts in that pic up against a Yankee ruler, so people like myself can get a good eye for the size!

Same goes for the C-o-C (and I know what that means!) done up in thous. 
Looking at that, it appears to be completely do-able, once one has the right sized bit or wire gage for making the orifice hole. This looks like a good job for a WW lathe.

Gary, the capillary tube sounds like an excellent idea! Thanks.

Dean


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## Noitoen (Feb 8, 2010)

Deanofid  said:
			
		

> capillary tube sounds like an excellent idea!



Small syringe needles these days are also very thin, maybe easier to find.


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## Blogwitch (Feb 8, 2010)

Andy, 

I will do my best, but I can't promise anything. If you need anything desperately, by now you should know what times I am prowling about on Skype.

Dean,

I know how fond you lads to the west of us are about the metric system, so I thought I would confuse a few of the UK lads this time. The problem being, the UK machinists most probably work in both anyway.

That tip from Gary really does make this little project 'do-able' for most people. But if it was me, I would make a few jets up like the drawing, with the tube 'stuck' in the jet. The hole is rather small, and would be prone to blockage, and having a couple of spares to swap in the case of emergency would be a good thing. Then you could unblock the jet at your leisure, not when you have an audience.

To a new person looking at the plans for the first time, they would soon be put off. But if broken down into the component stages, it is fairly easy to do, you have just to get your head around working in the smaller sizes and tolerances, most of which can be achieved with hand finishing, a bit of emery around a flat stick.

Blogs


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## steamboatmodel (Feb 8, 2010)

Hi Blogs,
Could one use the jets from the small camping stoves?
Regards,
Gerald.


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## Blogwitch (Feb 8, 2010)

Gerald,

The picture of the brass jet that I did above is off a propane burner, so it would be very similar to a camping stove, maybe just a different shaped package and thread.

You need to remember that these burners are small and are not capable of having a large jet fitted due to the physical size, the screw that is shown is about the largest that will fit in the available space.

So it is either 2-56, 8BA or even 2mm thread that needs to be in there.


Blogs


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## firebird (Feb 8, 2010)

Hi John

Great work as usual. I'm following this with great interest.

cheers

Rich


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## Blogwitch (Feb 8, 2010)

Hi Rich,

Not much been shown yet, more of a discussion at the moment, but if it is useful discussion, then it all helps in the long run.

Stew dropped me off some Stubbs silver steel yesterday, but I haven't been able to use it yet.

This evening I made another cutter out of the same material I made the one from before, exactly the same results. Just to prove it wasn't my technique going wrong somewhere. The supplier will now be informed of the error of his ways.

Anyway, I will be making a new long cutter out of the 'right stuff', and will give a bit more info as to how I did it, as I think someone new might appreciate the way it is done.

I have a day off tomorrow, so I might get it done then.

John


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## NickG (Feb 8, 2010)

Great stuff John,

the 0.020" hole sounds bad enough to me but 0.006" ? :-\

I was thinking when i was drilling my 0.040" hole in the hard brass the other day, it was probably the fact that it was hard and the swarf formation that allowed me to drill it. I was surprised it came out more stringy than brass usually does - probablty because the flutes are so small. the speed i was running was probably far too low in reality so wouldn't attempt anything smaller. I also doubt i'd try any aluminium or steel, maybe cast iron or stainless.

Can't wait to see your findings with this one. Thanks for posting.

Nick


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## Blogwitch (Feb 9, 2010)

Nick,

It is, in all probabilities, that your 'hard brass' is in fact one of the myriad from the brass/bronze family. Normal 'yellow brass' that we use almost always comes off as very fine needles or dust. I would suspect you have one veering towards the bronze family, which invariably comes off as a curly type swarf.

Drilling small holes can be a real PITA, and the only way to get around it is practice. Mostly it is all to do with 'feel', which can't be taught, only experienced, and so unless you do it yourself, you will never learn how to.
There are a few cheapo tools on the market, and I am sure there are plans to build one, and that is a sensitive drilling tool, which puts the control at your fingertips rather than on a large handwheel, and with one, you can 'feel' what the drill is doing.

Don't you worry about drilling such a small hole, as I told you a few months ago, one of these which I am making is earmarked for going onto that last Jan ridders engine you built.


John


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## steamboatmodel (Feb 9, 2010)

Blogwitch  said:
			
		

> Gerald,
> The picture of the brass jet that I did above is off a propane burner, so it would be very similar to a camping stove, maybe just a different shaped package and thread.
> You need to remember that these burners are small and are not capable of having a large jet fitted due to the physical size, the screw that is shown is about the largest that will fit in the available space.
> So it is either 2-56, 8BA or even 2mm thread that needs to be in there.
> Blogs


Its a bit clearer now, 2-56 and 2mm I can relate too. I had originally figured the burner was about the same size as a regular bunsen burner. For the rest of us in NA the Dia over the threads of an 8 BA thread is 0.086 inches. I found it on a chart here http://homepages.tesco.net/~A10bsa/bago.htm
Regards,
Gerald.


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## NickG (Feb 9, 2010)

I must admit the hard hex stuff was just being chucked out at work so I don't know what it is. It looks very dirty on the outside, doesn't look a bronzey type colour really though and with normal turning it came off in the needles, I just seemed to need a great deal of force to take a 20 thou cut.

Anyway, yes I have seen plans for sensitive drilling machines in the past, I believe what is now Hemmingway offer one http://www.hemingwaykits.com/acatalog/Universal_Pillar_Tool.html but this doesn't look high enough speed.

Wow, that is very kind John I am very grateful.

Nick


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## Blogwitch (Feb 9, 2010)

Wrong end of the stick, Nick.

The C-o-C below is what I was on about. I am sure a man of your calibre could soon knock one up


John


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## NickG (Feb 9, 2010)

Ah right, after posting I did wonder how that would help drilling in the lathe! That looks a good idea, would the speed of my lathe not be an issue though, what size would you think it possible to go down to with a setup like that?

Cheers for the C-o-C. Picture is worth 1000 words.

Nick


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## Blogwitch (Feb 9, 2010)

Nick,

It all depends on what speed the lathe chuck will go. If it wil go to around 1500rpm, I should think 0.015" to 0.020" should be achievable, but you really need to spot drill the centre first, just to give the drill a chance at life.

There was a vid on here at one time about a chap with a sherline drilling tiny holes with him holding the drill in his fingers, but I can't seem to find it.


John


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## Noitoen (Feb 9, 2010)

Blogwitch  said:
			
		

> There was a vid on here at one time about a chap with a sherline drilling tiny holes with him holding the drill in his fingers, but I can't seem to find it.



I think it's this one but I can't see it http://www.homemodelenginemachinist.com/index.php?topic=1454.0


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## Blogwitch (Feb 9, 2010)

I think I want to get away from the drilling discussion for the moment, and take two steps back, then one forwards.

Because I had a total failure with the long d-bit because of bad material, I thought I would do a bit of a post as to how I do it, from start to finish. Others may have other ways of making d-bits, I will be showing my way.

I am sorry if you have seen this before, but for the sake of the newbies amongst us, it should show them that it isn't magic or a black art.

First off I will try to explain my terminology. Silver steel in the UK is the same as drill rod in the US. UK engineers tend to go for water hardening and call it a day, the US guys tend to make life difficult for themselves, and go for all sorts of variations, I think from air cooled thru to oil cooled and everything else in between. I personally think they just like to baffle each other with numbers. I use the word topslide, you might call it the compound slide. 

So to start making the d-bit for this job.


A length of water hardening 3/8" diameter silver steel was mounted up in my collet chuck, with about 2.5" protruding. Now as most of you don't have such a chuck, you would need to mount one size larger into your 3 jaw, and have a little more sticking out and turn it accurately down to size and then leave it where it is, or if you can use a 4 jaw independant and clock a 3/8" bar perfectly true.
There is a reason for this, d-bits need to be made to, at the most, a couple of thou accuracy when halving, so getting everything cut concentric is the trick of getting a good one.







The brass blank will have a 5/32" hole drilled right thru it, so the first job is to put a non cutting follower on the lead in of the bit, this will help to stop the bit cutting oversize. This is 0.156" diameter by 1/4" long.







The area for the taper to go was cut to 0.325" diameter by 0.840 long.







Followed by the gauze recess, I made mine 1/8" long by 0.345" diameter. On the plans I think it calls for only 1/16" long, but for mine, I want to put a retainer ring in, rather than having friction hold the gauze in position.







Now comes to what I think scares people the most, but if you follow the way I do it, you can get your taper, and any in the future perfectly good enough for the job in hand.
I have already done the calculations for you, and have rounded the numbers out. The angle is around 6.4 degrees and the OAL of the taper is what I have already cut.
The topslide degree markings are not all that accurate, so I set mine to, by eye, what I thought was 6.5 degs. More on that later.







The toolpost was swivelled to a couple of degrees short of having the front cutting face square to the job. This ensured I had plenty of clearance at the back of the tool. As it was, it still nipped my a**e, but not in a critical position. If you are using other tooling, you could just grind a lot more rake on the tool.







Then with the saddle locked up, I used the crossfeed to put on the cut and the topslide to make the cut. I use a hand over hand feed on the handle when I am manually cutting, I find I can get a much smoother finish on the job







This now shows the inaccuracies in my topslide scale. The small end of the taper is in the correct position, but the large end is too large, it hasn't reached the face that I cut.
To cure this, I retracted the cutter, slackened off the topslide nuts and took a tiny amount off the degree scale. I did this twice before I was happy with the angle.
Now this is a little tip, when cutting tapers like this, always start off with too much angle, you can always take another bite to get it right, but if it is too shallow to begin with, you are in trouble. It works the opposite way if the taper is the other way around, say boring a tapered hole.







So this is the end taper, and as you can see, at the small end it went into the guide on the end, but not to worry, that bit doesn't make any difference, it is just the joining diameter between this taper and the belled end will just minutely longer.







Then I hacked into that nice taper with a big profile tool, just to give the slight curve that is required.







A bit of file work and some emery followed by wire wool gave a good surface finish. The better the finish you can get, the smoother the bore you will cut.







This part is the critical bit, this is where you cut the d-bit down to almost centre.
The blank needs to be perfectly level with your machine table, I am lucky in that I have accurate 5C fittings that allow that to be easily achieved, you will have to resort to laying level on parallels.
Notice where the cutter is sitting, the cutter really needs to cut at least half it's diameter onto the original unworked material. The reason for this is that it will be easier and more accurate if you can measure the original size rather than where you have been working, with all it's lumps and bumps.







I don't even start measuring until I am a fair way down. I take about 20 thou cuts to begin with, then when getting close that gets really knocked down, with my final cuts only 1 thou at a time, very fast cutter speed, slow feed and a squirt of lube.
This pic shows how easy it is to measure when you cut into the main bar.
The dimension you should aim for is one or two thou thicker than half the diameter of the bar. In this case, the bar is 0.375", divided by 2 is 0.1875". I have decided 0.189" is where I want to be.







I am happy at a couple of tenths under.
Take notice of the ragged edges. I DO NOT deburr at this stage. because you are working in thou tolerances, it is too easy to deburr an edge and not to be able to get it sharp again after hardening. You are liable to put flat spots onto critical edges.
What I do, is to heat it up as is, then in the quench, most of it will fracture off by itself, and what remains is worn off when you sharpen the tool.







Brought up to temperature and held there for a couple of minutes, then it was swizzle quenched in a large container of water until fully cooled.







I did a file test this time, and it was glass hard.
Some people temper at this stage, but for a tool like this I just leave it hard, unless I am to be cutting some tough stuff like hi carbon, stainless or phos bronze. For brass, cast iron, ali or FCMS then I leave it. I have never had one fail yet.







You now need to sharpen, and normally I wouldn't have used the mill at all, but hardened it first, then halved it on my surface grinder which automatically leaves it sharp. But this time, I used a common oilstone, with plenty of oil to lap just the halved face. You should be able to achieve edges that are sharp enough to shave with. With the allowance you have left on there, you should be able to resharpen a few times before you go under the half limit, then you will have trouble getting it to cut. I did no other work on it, no reliefs or backing off. I find it will do this job perfectly well without them.







Lathe RPM at 500, good strong feed and it is a gud 'un. Just make sure the swarf is kept clear and it will cut almost as fast as you can feed it.







This lot took only minutes to finish off, and if the d-bits are not abused, they should be able to cut hundreds, if not thousands of these.







I hope you weren't too bored with this. Next time, I think I will get on with the control valve.


Blogs


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## NickG (Feb 9, 2010)

John,

Thanks again for that step by step d bit guide. Brings me to a quick question on the subject. I think you've probably answered it before. I have some 5/32" holes to size accurately but no reamer, could I make a D bit for that purpose? I have some 5/32" silver steel, which is also the shaft that shall be going into the hole. Presumably the shape would just be the ss 5/32 stock milled down to say 0.0795" and hardened? Could save me buying a reamer?

Nick


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## Blogwitch (Feb 9, 2010)

Nick, 

D-bits can be a very good substitute for a reamer, but they are made slightly different to what I have shown here, with a frontal cutting edge.

I don't want to go into details here, as it will go the same way as when I mentioned drilling a hole, earlier in this post.

I think it was all explained over on Madmodder. I know I opened a post about it, to stop a post like this being flooded, but I can't remember what was said.


John


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## Deanofid (Feb 9, 2010)

John, what's FCMS?

I put it in google, and got a bunch of stuff about bridges. HumoUr us across the water.

Ta

Dean


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## Blogwitch (Feb 10, 2010)

Sorry Dean,

Free Cutting Mild Steel. The standard term used for it in the UK, but EN1a if you want to get technical. It is normally just a standard, general purpose, used for everything, slightly leaded (Pb) mild steel.

This is what we would consider a normal sort of metal selection chart from a factor to be. From a metal wholesaler the lengths would be in 13ft rather than 300mm (1ft).

http://www.metal2models.btinternet.co.uk/bms1.pdf


Now the world knows all our secrets.

John


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## Deanofid (Feb 10, 2010)

Thank you, John. 
I suppose the world already knows all your secrets. Just one chubby feller in Idaho couldn't figure out the letters.
; )

I did already know what silver steel was. How about that. It's a much snazzier name than "W-1 drill rod".

Appreciate you showing this D reamer process. Even though I've made a lot of round ones, and other cutter types, never had the occasion to make a full diameter inside form cutting tool. Pleasure watching your shop work.

Dean


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## SAM in LA (Feb 10, 2010)

John,

Thanks for spending the time to write the D-Bit tutorial. :bow:

I read everything that you post knowing that I am very likely to learn something new.

I am confident that if I follow your instructions, I can make what ever it is that you are describing.

Recently, I built a mill tramming tool as you described in a post Feb 2009.

Thanks once again,

SAM


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## Blogwitch (Feb 10, 2010)

Nick, sorry to have been a bit terse, but anyway, here is the post I mentioned above about d-bits

http://madmodder.net/index.php?topic=2312.0

Dean, the above link shows what you really can do with d-bits, they are very versatile, but much underated.

Thanks Sam, just trying to help out. Hope the tramming tool worked OK for you, as it has done for a fair few people now.


John


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## Deanofid (Feb 10, 2010)

Hi John;
I remember coming across that page not long after I first started reading that forum. Between yours, and the other fellow's shots, there are a lot of shapes to think about. Don't know why I never thought of using one in a shape other than plain round, but with prints for this same burner on the way, it's very pertinent now!

This is the great thing about seeing other people's work. Even if a guy has done it, there's always the possibility of another, and maybe better way.

Dean


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## SAM in LA (Feb 10, 2010)

Blogwitch  said:
			
		

> Nick, sorry to have been a bit terse, but anyway, here is the post I mentioned above about d-bits
> 
> http://madmodder.net/index.php?topic=2312.0
> 
> ...



John,
The tramming tool was a challenge for me since my machine still needs some repairs.

Thanks again for the tutorial.

SAM


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## NickG (Feb 11, 2010)

No worries John, quite right - I knew the thread you meant as soon as you mentioned it. I will definitely try that method.

Cheers,

Nick


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## Blogwitch (Feb 11, 2010)

Dean,

Please remember, when you get your plans, I am modifying the top end of the stack, so a few of the measurements have been changed from what the plans say, namely the diameter of the top of the taper and also the diameter of the gauze disc. I have shown you how to make the d-bit, you could just mod my figures to match what you want to do. With something like that area, I don't think anything is written in stone, so you can mod it almost any way you want, as long as you don't restrict anything. As shown on the web site, and a thing I will be doing with a couple of these, Jerry even turned the tops thru 90 degrees.

Now back to this build. You may have noticed, nothing has been done with this over the last couple of days. The reason for this is that my quack has doubled my morphine dose, and my body has been getting used to it, like I have been sleeping for almost two days, broken by bouts of almost awake, good enough to surf but I am a bit unsafe to work on machinery, but if all goes well, by tomorrow I should be safe again.

Anyway, just to keep a bit of interest going, these turned up yesterday.







The 2-56 screws are what I have been waiting for, and are for use if anyone needs a US threaded jet. Very nice quality and no problems with the seller, took just over a week to get from the US to the UK by snail mail. Ebay # 130297242699

The other item is nothing to do with this post, just my magpie instinct for shiny things that will be used at a later date.

These are Bosch Rexroth linear bearings from a chappie in Slovakia, who is stripping some good bits of machinery down. These cost less than 12 squid each including postage, and if anyone knows about these things, they were a bargain. They were supposed to be used, but they are just like brand new. He has some other very nice stuff available if you are into this sort of thing and know what you are looking for. This is an ebay number for these types of items, 170439636831, and from there, you should be able to see what he has to offer. They took 10 days to get to me. Again no problems with the seller.

So maybe you might get a bit more of the machining tomorrow. 


Blogs


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## shred (Feb 11, 2010)

Blogwitch  said:
			
		

> Now back to this build. You may have noticed, nothing has been done with this over the last couple of days. The reason for this is that my quack has doubled my morphine dose, and my body has been getting used to it, like I have been sleeping for almost two days, broken by bouts of almost awake, good enough to surf but I am a bit unsafe to work on machinery, but if all goes well, by tomorrow I should be safe again.


Ugh, I know how that goes. You want to be in the shop but don't really have the energy or control. Hope it gets better fast.


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## Deanofid (Feb 11, 2010)

Hope you're doing better soon, John!
Sometimes the doc has some strange stuff in the old medicine bag.

Take it easy,

Dean


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## Blogwitch (Feb 13, 2010)

Sorry to have dragged on with a post that should have finished ages ago.

Now my brain cell is in sync with my body a little better, I have managed to get a tiny bit more done today.

I went over the whole planset to work out what material I required, and to see if anything could be changed to suit what I already had.
I also redesigned the control valve to what I consider a better and easier setup for me to to make, plus the o-ring can be easily changed if needed.
Jerry shows how to make various versions of the needle valve by the use of bits out of disposable lighters., so my mods shouldn't make any difference. As mentioned before, you make it to how it says on the plans if you want to.







The body sleeve, to me, is another important part of this unit, and the 3/8" tube has a thicker wall than what it states on the plans. Maybe the one he used was from another supplier, and might be available from somewhere like K&S as standard.
I had forward planned on this, and is the reason I didn't finish off the stack before this part was made, as all these parts are reliant on the measurement of each other, and the internal measurement of my tube is what the parts will be made to.
So here is the tube in the lathe. 
I know that my topslide is perfectly square to the spindle, so I can put on accurate measurements with it's leadscrew.
Saddle locked and using a 0.050" wide grooving/parting tool I faced off the end, and zeroed up the scale.







Forwards on the topslide handle by 0.800", 0.050" tool width plus 0.750" part length, the tube was parted off.







Not far off at all.







I knocked off a few more at the same settings.







I measured the internal dimension of a few of them, and they all came out the same. 
So I need to prove the figure, as it is critical for all the parts to fit together correctly.







A bit of rough oversized bar was mounted in the chuck.







It was then turned down to the figure I had obtained, and the tubes fitted perfectly. I now know that if I use this figure, no sloppy fits will be made, mainly because I want the stack a tightish, but removeable fit, so that the jet can be changed easily. That is as far as I could get today, but I will show you a bit more about the drill I will hopefully be using to do the jets. I did this work before I cut these tubes up.







I have a bench magnifier, but it is a little large to get near to the drill, and I also have a set of magnifeyes, but for drilling, I need a little more mobility, not having to swing them out of the way when I require normal vision. So I bought one of these, the fifth one down, with the horseshoe shaped base.

http://rdgtools.co.uk/acatalog/MAGNIFYING_LIGHTS.html

Even though it is only 2X for the main lens, it gives very good magnification and clarity up to a good distance away.







The weighted horseshoe base was easily screwed off, and I made a much smaller ali one with four neodindinaineum rare earth magnets fitted in. I can stick it anywhere I want it on the machine, or even on the lathe or mill if I am doing tiny work.







With the led lights on (run from a battery in the glass holding head), I have a great view of the drill tip, to see how it is progressing thru the job.







Gradually getting there.


Blogs


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## Deanofid (Feb 13, 2010)

Thanks for the new post, John, and glad you were doing well enough to get back in the shop.
My prints for this burner showed up yesterday afternoon. It looks like you'll have all the head scratching
stuff done before I get started, which will make it easy on me!

You may find this interesting, or even useful sometime;

After having a look at the jet that came with the prints, I noticed a concentric ring a ways out from the tiny hole in the jet. It looked _very_ familiar. Just like clock plates look after I've pressed a new bushing into one.

The prints say he used a sapphire, but the one in my jet is not that. I'll bet a dollar to a doughnut that the "jet" that is pressed into the 2-56 screw is a KWM brand #L-56 brass clock/watch bushing. I happen to have a KWM chart here, since I do this stuff now and then, and it says an L-56 is 1.2mm thick x 1.0mm dia x 0.15mm bore. That just happens to be almost exactly 0.006".  They come even smaller, and much larger. Lots of sizes, (different part #'s).

In the U.S.A., these bushings are common and cheap. About $9 per 20. I would expect them to go for even less in the U.K., since KWM bushings are made in Germany. Much closer to you than to me. There may also be a Brit version of these. There's an American version here, that uses a similar sizing system. 

I realize you're making your own, and are pretty much setup to do it, but if you should need a bunch of them, these might be the ticket. Like for when you get an order for 50 of these neat little burners...

: )

Dean


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## Blogwitch (Feb 13, 2010)

Dean,

Making the jets with a pivot jewel seems even worse to me than trying to drill one, but again, if you are used to working with that sort of thing, then there is nothing to stop you going down that route, and it is another method mentioned by Jerry in the plans.

I was hoping that by the time this post is finished, it might encourage a few people to have a go for themselves, just as you will be doing, and also show that the plans aren't the be all and end all, just a guide, which you can alter to suit whatever you have in your shop.

These burners which I am making are for my own use mainly, but I was going to make a few extras of the jets for anyone who thinks they aren't up to making them. But by the time I am finished, all the little holding fixtures and cutters will be there if I need to knock out a few more. Unless of course, someone comes up with a lucrative contract.


John


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## Deanofid (Feb 14, 2010)

Hi John;
I didn't mean to sound like I was trying to convince you to do it another way with what I wrote about the brass bushings. Like I said, I realize you are set up to drill your own. 

Please carry on. I read all your threads with high hopes of learning new things.

Dean


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## Blogwitch (Feb 14, 2010)

No Dean, it was perfectly fine.

The more ways to do something, the better in my opinion. It gives the viewers more choice with what they have in their shop.

The plans are a little confusing to start with, because of the extra ways of doing things Jerry added. But once you disregard those bits, it is a very simple build, just that a few techniques are needed, and that is hopefully what I am showing.

Here is a drawing I got from my archive, and it gives you another choice for making the pressure regulator. You would need to make the threads for the can adapter different if they are not the same as the UK ones. I have just got to get the 1mm neoprene for the diaphragm.


John 

View attachment GasValveAndRegulator.pdf


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## NickG (Feb 14, 2010)

Glad to see you got back in there John and made some good progress. I admire this as I find it difficult to motivate myself to go in and I've got no excuse, I'm just a lazy @rse at times.

Well done.


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## Blogwitch (Feb 16, 2010)

A bit more added to this overly long post. This time I am finishing off the body sleeve.


If you remember on the last post, I had used a bit of brass bar to verify the internal fit of the tube I am now working on. I took that, and turned a little more off it so that the tube was just a little longer than the turned down bit. If you look carefully, right next to the shoulder, I went deeper with the lathe tool and formed an undercut. That will allow the tube to sit right up to the shoulder. If I hadn't have done that, the small radius imparted to the internal corner by the cutter tip would be liable to hold the tube away from the shoulder.







The end was drilled and power tapped for a small screw.







By the use of an oversized washer, the tubes can now be safely gripped onto this holding mandrel.







There are a few ways that this next bit could have been done, with the RT sitting upright, the ideal would have been using my spindex, but because I haven't got full strength back in my fingers yet to manhandle them, I had to settle on my 5C square block and the vice back stop.







With the block pushed back to the stop and down onto the vice internal base, it was an easy job to centre the tube and find the position of the datum shoulder (the very end of the tube).







It was easy then to backstep to the drill position, and using a good quality drill, go all the way thru the job. Turn the block thru 90 degs, and repeat. Remove tube, put another one on.







In next to no time, they were all drilled.
The first one was a bit tight to get off because of the burrs thrown up on the mandrel. But once they were cleaned off with a bit of emery, everything went on and off with no problems.







A large hole now needed to be cut at 45 degrees to these ones I had just cut. So a piece of close fitting bar thru the mandrel (I used a transfer punch), the collet was loosened and the mandrel turned thru the required angle. This angle isn't super critical, but the distance between the big and small holes is. I just used my little digi angle gauge, but a standard protractor would get you plenty close enough. 







Because I had been playing about with the mandrel, the datum for the shoulder had to be refound and the position of the large hole clocked in.







A sleeve put on the mandrel, a drill bit thru the original holes to get the sleeve in the correct rotational position then all tightened up. A very sharp centre cutting end mill was then used to just cut thru the tube and slightly into the mandrel. Turn thru 180 degs and repeat for the other side.







Again, things done in no time at all.







All these little bits and cutters that I am making will be put in a box and marked up, they will come in real handy when I want to make some more of these burners.



Blogs


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## ksouers (Feb 16, 2010)

The little guys are coming along nicely, John. Good luck with the arm, I hope it comes back to shape soon.

Lots of great tips and shortcuts. All duly noted and bookmarked for future reference.

Many thanks.


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## Deanofid (Feb 16, 2010)

Thanks for another very instructional post, John. 
Things are coming along nicely!

Dean


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## Blogwitch (Feb 19, 2010)

Sorry it is taking so long gents, but when you can only work in ten minute bursts, even a small job becomes a major one.

So this time, I am making the jet and control valve holder. As far as I am concerned, the jet part is the most critical bit, because it not only has to be gas tight, it also has to be totally square to the main stack, otherwise the gas plume will be fired off to one side and maybe not burn correctly.

I started off by turning some stock down to be a snug sliding fit inside the body sleeve, and parted off to basic length. There is no mention, as far as I can recollect, of how all these bits are joined together, so I have decided to do some very fine silver soldering on mine, and that will require a small gap to allow for the capillary action of the silver solder and flux.







The holders were faced off each end to bring them to spot on length. Then each end was spot drilled. It didn't really need both ends doing, but with this build being so small, even having the base mounting screw slightly off centre will make the assembly look badly made.







On just the jet end, a chamfer is put onto the part. This is a certain size, as when assembled, this part extends slightly past the air inlet holes in the body sleeve. This chamfer allows the free flow of air from the holes to the jet area.







Each end was drilled to the correct size for tapping for my 8BA sized screws. For the drawing version, you would need to drill for 2-56 threading.

The holes didn't meet in the middle, they were drilled just deep enough to penetrate into the cross drilling area.







And this is where the cross drilling starts.
First off, by using my centre finder and a parallel clamped in the vice, I got the chuck spot on centre of the part diameter.







Now this is where things can get tricky. There is not much to grip on each end of the part for drilling the large cross hole. So I will show you how I got around it.

I will just mention now that you could hold the part across the vice, resting on parallels, but for a quantity amount, I didn't want to risk having the part not square across the jaws, hence the way I did mine. Just me being paranoid.

I am lucky in that I have some 3" long parallels, and by stacking them up, I could get to the height I wanted.
I put a strip of double sided tape across each pair, then clamped the pairs into the vice to leave the correct gap between them. All four were stuck to the fixed jaw, so that they won't move out of position.







The part was rested onto the parallels, equally, either side of the gap, with the jet end away from the backstop.
Then the back stop was brought into position, so that every part should end up in the same place each time. 







With everything tightened up, I took a reading off the non jet end of the part, and positioned the chuck in the correct position for drilling.







The part was removed and the drill was checked for clearance as it went into the parallel area. It looks tight, but it isn't really, just a hoptical dillusion.







Part in position, and a fairly large spot drill put in. Because I am going thru in one hit, there is no way I want the large drill bit to wander as it goes down past those curved sides.







The drill is 1/64" smaller than the stated diameter. This is a reaming allowance for after assembly with the body sleeve.
I took it steady as it went thru, especially as it went past midway, where the two end drillings were. I didn't want to have an oversized hole at this late stage.







As it was, no gremlins appeared, and everything went very smoothly.







So back onto the lathe.
I broke out my mini tapping tool and power cut an 8BA thread into each end of each part.







After the first one was cut, I tried the screws that are to become the jets, just to make sure they were a good, non sloppy fit.
This shot also shows up a problem that normally happens with commercial screws. They just never get the threads right up to under the head, so an allowance has to be calculated to counteract the hold off gap that would be created if the screw and hole were left as they were. I usually use a length of 1.5 times the thread pitch (just roughly). For my 8BA threads, 0.025" will be fine.







So using a 3/32" milling cutter (just a little larger than the OD of the threads), I touched on, and then cut in the required amount.







As you can now see, the screw now goes all the way in, and I reckon, the jet will not require a sealing washer because of the good fit of the screw under the head and in the threads.







That's as far as I have got with the build, but because I was asked about my power tapping tool, I will show you that you don't have to spend big bucks to make tooling.
On the LHS you can see a commercial mini tap wrench, I bought this hundreds of years ago, and it is still going strong, maybe because it cost an arm and two legs back then, and I still think they are pricey now.
On the RHS is the way I got one for making my mini power tapper.
If you notice, it is part of a set of real cheapo pin vices. The commercial one has a square set to the jaws, but if you mount your tiny tap with the corners into the jaw slots, it clamps up just as well, and runs perfectly true.
The knurled part was turned down until the knurl was just gone, then the shaft was measured. An old large bolt was turned to the shape of the holder you see. I had it that shape so that it cannot be pushed right back into the chuck jaws, and maybe cause damage if something broke and the holder had a backwards knock.
A hole was drilled and reamed thru it, just smaller than the shaft on the modified pin vice.
Then the pin vice shaft was turned down until it was a nice snug sliding fit in the hole. A bit of 1/8" silver steel was loctited into a cross drilled hole.

Total cost, apart from a bit of time, about 4 or 5 bucks.






Slowly but surely, we are getting there.


Blogs


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## Deanofid (Feb 19, 2010)

More good progress, John.

I doubt anyone is concerned with the rate at which you proceed, here. Where else are they going to get such an education?

Thanks again for all the pics and words.

Dean


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## Cedge (Feb 19, 2010)

Interesting project John

Steve


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## Blogwitch (Feb 19, 2010)

I hope it is Steve, lots of little techniques to be used.

But I am sure, now that I have got this far, maybe not the jet, but all the rest is well within the scope of the layman who can work to fairly fine tolerances and take their time on getting a good fit.

I can't wait to see how my twin licker will run on them. It ran fairly well when I bodged up a couple of gas burners when I first made it, but because they were so dirty running, the engine clogged up. Supposedly, these don't suffer from that problem.


John


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## Blogwitch (Feb 20, 2010)

This has been nagging me for hours.

Having just reread my post, it looks like I did one cut at the wrong time.

If I had left the chamfer at the jet end until the second lathe stage, just before I tapped the jet thread, the part would have been a lot easier to hold on the mill and it wouldn't have been endways critical.

I normally do a machining routine first, to show up any holding problems. But because I thought it was such an easy part to make, I didn't, and made life difficult for myself.

Next time, I will make sure I do.


Blogs


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## Blogwitch (Feb 20, 2010)

I managed to get a little further with this project, not a lot, but enough to make up a post.

Before I start to silver solder bits together, I want to machine the pushing together parts while the metal is still hard. This is because for a few weeks after soldering, some of the metal parts will be softened by heating, They should age harden a little while other bits are made.

So using a razor sharp HSS tool, the bottom end of the stack was brought down to size to be a push fit inside the body sleeve, to the length stated on the plan. The reason for the HSS tool is that the carbide tipped ones that I normally use have a small radius on the tip, and so the two parts won't mate together tightly because the radius on the machined bit will hold them apart.







A nice tight and close fit.







Now we are ready to start the first silver solder assembly. The jet holders will be inserted into the end until the big holes line up.
You can see in this shot how small this unit is. 1.75" long, without the base.







If you have made these bits to plan, you should find that when the main holes are in line, there is a recess in the bottom of the unit. Jerry must have done this so that when it is mounted onto a base, it will pull down nice and tight onto the tube edge and so form a neat joint.
I am going to use that recess to my advantage, to hide the silver solder joint in there.







All the bits were assembled, and in each recess, I run a bit of liquefied flux (flux+water) around the inside edge, and then placed a half moon shaped bit of silver solder wire in there as well, pushed up to the outer edge.







Ready for soldering.







A few seconds later, after a flash over with a big burner, all have a perfectly formed fillet joint with no runout of solder onto the outside faces. They were then dropped into a citric acid bath for ten minutes, just to get rid of excess flux residue.







This is after they came out of the acid bath. Notice how neat the fillets are, and how little flux has gone onto the outer faces. 
I have no idea why people have so much trouble with silver soldering, it really is as easy as I have shown it. The flux is the secret, I have used the Tenacity range for many years now, it is now up to Tenacity #5, and is really designed for stainless, but is perfect for almost all metals as it doesn't suffer the flux burnout as most others do.







I reamed thru the big cross hole, which tidied everything up, and cleaned off the rest of the flux with a bit of wire wool.







It is now ready for having the gas control valve making, which I should be doing in the next post.



Blogs


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## spuddevans (Feb 20, 2010)

Great writeup John, while I have no plans to make a mini gas burner, there is still a lot to learn that can be applied to other situations, so thanks for showing your process and explaining it so clearly.



			
				Blogwitch  said:
			
		

> I have no idea why people have so much trouble with silver soldering, it really is as easy as I have shown it.



That is so true. For folks who have never silver-soldered, just try the method that John shows here. Up to relatively recently I had never silver-soldered, but sticking to the method John explained in the paddleduck engine plans meant that after just one practice joint ( that turned out ok, amazingly to me ) I have been able to solder up a number of joints with only one joint not perfect ( but that was easily fixed ).

This really does open up so many engineering "doors" so it is well worth trying it.



Sorry about the slightly off-topic rant, back to your usual programming.

Tim


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## Blogwitch (Feb 21, 2010)

Thanks for the confidence in the method Tim. I'm glad someone has been assisted by my posting.

Back to the main issue now.

For all the ones who have the plans, you will now notice that I will be deviating slightly. There is nothing wrong with all the methods Jerry has shown how to do this part, but I am stuck in my ways a little, and I will be doing it my own way.

This pic shows how the needle is fashioned on a commercial steam valve I used to make. Instead of it being just a straight needle, it has threads that screw into the body of the component. It is a little more work than the type shown on the plans, but after pressure testing many of these items, I know they will easily withstand 120psi, which is a lot more than the regulated gas supply to be used with this burner. I am sticking within my own safety margins.








So after a bit of working out, I have the sizes for the blank to be made to, and a rough sketch working drawing.







I was lucky when rooting thru my stash box, I came across a few short lengths of brass rod. They must have been used in some sort of heating system, because the OD was all different sizes along its length, and there was a deposit of some sort on there, maybe it came out of a nuke reactor or something like it. I always wanted to be able to glow in the dark. ;D
Anyway, I should be able to get the sizes I want out of it.
But first, I need to set up my taps and die.







I have decided to go with 5/16"x40 Whit, a standard ME sized thread.
A 7.3mm hole was wacked right thru a short length of brass bar, and I cut a thread from each end, that didn't meet in the middle. Just to make sure I got standard cut for the tap.







Next, I chucked up a length of my brass bar, and by coming down gradually with the die size, and checking it with the internal threads I had just cut, I got a good match between the two. A thread was cut on each end of the bar. The die will be left undisturbed in it's holder until the job is finished.







The threads fitted perfectly, even when swapped about with each other, but now having tried them on this material, I think I have made the wrong choice. It might be OK for steel, but on brass, I suspect it is a little weak.

I will do the same test, but with a 32TPI thread of the same diameter. I think it will be a lot stronger







You win some, you lose some.


Blogs


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## Deanofid (Feb 21, 2010)

John, do you mean that 40 tpi is too fine for this size, (and material)?

Thanks,

Dean


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## Blogwitch (Feb 21, 2010)

Dean,

I personally think that it isn't correct for this job.

You know the feeling, sometimes you get a gut reaction that makes you feel that it isn't quite right for what you want to do. Crossing threads or stripping out because of how small the threads are for such a large diameter. As I said, maybe OK for steel, but not for brass.

It isn't a problem, it will only take another half hour to test and set up the die for the next TPI size.

That is one of the advantages of Model Engineering threads, you can have the same diameter, but up to three different choices of TPI.


John


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## Blogwitch (Feb 22, 2010)

First thing I did was to set up for the 32TPI threads, and so I set the die and cut a pair.

I am now happy with the result, and this is what I will go with. A much more robust thread altogether, and still in keeping with the scale of the job.







That then left me with getting on with the control valve.
So going with my sketch, I turned down the length and diameter needed.







After I had done the first one, and tried it thru the jet holder, it looked a little too long. The next one I cut was 1/8" shorter, and this looked much better all round.
It is always the same when you are modifying something, it takes a little fine tuning to get it just so.







Now with the new length, the tubing spigot was turned to what is shown on my sketch.







It is at the stage now where I totally disagree with how Jerry has made his tubing nipple.
Thru many years of use of silicone fuel tubing, I have come to the conclusion that having any sort of sharp edge fitting, will cause it to fail very quickly, just a small nick into the material, and it will tear. So I have come up with my own solution over the years, and have found that this causes no failure problems, and grips just as tight, maybe even tighter.
I will explain as best as I can, and hope you understand the process.
Using a normal threading tool, the tip was aligned with the very edge of the end face, then plunged in by 0.020", this forms a lead in taper on the front end of the spigot. The tool was retracted, moved along the spigot by 0.100" and was again plunged in by 0.020", this was repeated twice more along the spigot.







This is what it comes out like, and it has already had a little wipe over with wire wool. The lighting makes it look like it still has sharp edges, but it hasn't. On final polish up, the edges will be rounded over a little more.







The tubing goes over the spigot really smoothly, and where the depressions are, the soft tubing settles into it. But when you try to pull it off, it grips like my wife when she has hold of my wallet. 






Just one more little job on this end of the valve, then it is onto the threading and drilling bits at the other end. But maybe not tomorrow, I have lots of other things to do.


Blogs


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## Deanofid (Feb 22, 2010)

John, thanks for the update, and for letting us know what you found regarding the threads.
I like your way of making the barb, too. Not only easier on the hose, but a better way in the machining sense, too.

Dean


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## Blogwitch (Feb 25, 2010)

I'm very sorry that this is taking so long, but I am still trying to shake off the bad side effects of a medication change. It is taking a lot longer than the last time I had it done.

Last post I had made the tubing spigot, this time I am going to be doing first, most probably the most important hole in this part.
On the spigot end, I spot drilled just to make sure that this hole was really in the centre.







The hole needs to be perfectly straight, because the other end of where this hole ends has to be perfectly centred as the control needle will use the edges as a seat for controlling the flow of gas. If it is too far off straight, the needle won't seat correctly on the end and thus will give bad metering of the gas.
Using a 0.040" (1mm) drill, the hole was gently peck drilled to a depth of 0.625" (5/8").







Once all the holes were drilled, after a collet change, the ends for the nut threads were cut to length (1/4")







The previously set die was now used to thread the end.







Then a nice small lead in taper was put onto the threaded end. This doesn't need to be large, otherwise it will intrude onto the flat end face where the o-ring will be seated on.







Each one was then checked for perfect fit into the test sleeve I had made before.







The next time I will be making another d-bit (but not showing the whole process) and getting the inside of the valve ready to take the metering needle.

I know this post is very long winded, but I want to show, if possible, that these things can be made by almost anyone, just by joining the dots.


Blogs


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## Seanol (Feb 25, 2010)

Bogs,
Don't worry about long winded. You show your way and we all can learn from the various setups and ways you approach the work.

That is very valuable information and something I need as a beginner. With no one watching over me as I complete my steps to make a part I have no feedback as to the proper order.

You capture the order as well as the reason behind that order (and even capture why you should have done it a different way) and that makes the post ideal for someone just starting the steep learning curve this hobby has.

Thanks for the informative posts and hope the meds get easier,

Sean


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## xo18thfa (Feb 25, 2010)

This is a great topic. Watching with much interest. One of these may end up in the "Nina" build.


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## ozzie46 (Feb 26, 2010)

Seanol  said:
			
		

> Bogs,
> Don't worry about long winded. You show your way and we all can learn from the various setups and ways you approach the work.
> 
> That is very valuable information and something I need as a beginner. With no one watching over me as I complete my steps to make a part I have no feedback as to the proper order.
> ...


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## Deanofid (Feb 26, 2010)

Seems like you're moving along fast enough to me, John. After all, making nine of everything.

Mine is barely half done, and I'm only making one!

Thanks again for all the photo's and comments you provide.

Dean


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## Blogwitch (Feb 26, 2010)

Thanks gents.

Dean,

I am in fact only making six. But I am always wary of damaging one when making exact numbers. There is nothing worse than going back and having to do all the setups again just to replace one part.

With something like this, which will be an ongoing thing, depending how many engines need them, I am not worried about having bits left over. With very little work, another unit can usually be knocked up out of the left over bits plus maybe one or two newly made parts.

All purpose made tooling for the job, sketches etc, and any parts left over, get put into a little box and then into deep storage in my 'back room'. Ready for reuse whenever needed.

For say a one off engine build, only the required numbers are made, and the tooling reused for something else, if possible, after the end of the job.


John


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## Blogwitch (Feb 27, 2010)

I managed to get this one part finished off today, so away we go.

But before carrying on with making the part, there were a couple of things that needed doing.

I don't have a tap that will cut threads to the very bottom of the nut that I will be making, but by using a mains powered mini drill mounted with a grinding point, and a first cut tap, I will make just what I want.







By having the lathe chuck running fairly slow, and a jet of air to keep things nice and cool, I ground the previously tapered end off.







After the bit on the end was off, the end was gently hollow ground, and by being really careful, I managed to get the first thread ground with a small taper. 
This was all done freehand.







It was checked to see if it would feed into the hole by trying it on the test piece I had made. It screwed in perfectly with no sign of wanting to deviate or cut any more metal out, just what I was after.
So that is the first bit of tooling done.







The next was to make a D-bit for flatting off the bottom of the hole that the needle will screw into. This will enable the taper point to make it's own very small seating area.
It was made to 0.090" (2.3mm) diameter. The same size as the drill used for cutting a 6BA thread.
That is the last bit of special tooling required at this time for me to proceed with the project.







Next thing was to make a crib sheet so that things were in the correct place and to the right dimensions. 
These things look very difficult to achieve, but in fact it is very easy. 
I am a DRO fanatic, and have one on my tailstock, so I can actually drill to a tenths tolerance. But as most of you won't have such a thing, small pieces of tube slid over the drill or D-bit, and by using a vernier to get the length required by pushing the cutting tool so that the correct depth is protruding, then tighten up the drill chuck. The tube will act as a dead stop as soon as it touches the part in the lathe chuck. Very similar to what I show later when tapping to depth. If you need a C-o-C then just ask.







Now come all the boring drilling pics, but they need to be done to show the order to do it in,
First off, gently drill down to depth.







Followed down with the D-bit to depth.







The 1/8" recess in the end was done with a multi flute end mill.







I tried to get a shot of the flat face at the bottom of the hole that the D-bit formed, but it went slightly astray.
If you close one eye and squint with the other while standing on tiptoe, you just might be able to make it out.







So that is the hole to size and depth, next comes the tapping.
I got out a set of matching tap & die as later I will be cutting a bit of tough stuff, and these HQS bits work wonderful on it.
If you look at the tap, I have stretched a bit of silicone tubing over it, and the length of the thread protruding is the depth I need to go to. I can go a bit deeper, but not shallower. Because I power tap, if I had a rigid stop on the tap, and I went in a bit too far, the tap would be liable to snap, this acts as a safety depth stop in case that happens. If you are tapping by hand, as mentioned above about the drilling, you could use a bit of tubing with the right amount of thread showing to get you spot on depth.
This is a plug or bottoming tap for you in the US.







Power tapping all the holes only takes minutes. If you only ever make one or two of something, it isn't really worthwhile setting up for power tapping, but if you do a lot, it sure saves your aching fingers.







Nice clean holes with well formed and perfect sized threads brings this part to it's conclusion.






Just the nuts and needles to make.


Blogs


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## Blogwitch (Feb 28, 2010)

So now we come to the sealing nut for this valve. I redesigned this unit so that if necessary the o-ring can be replaced in a matter of seconds and also it is very easy to put a little more pressure on the ring just in case it does start to leak.
I have just noticed how many pictures I have used in this post already, well over a hundred. For such a small item, I hadn't realised just how many machining operations are required.

The first thing I needed to do was to sketch up the part, with all the critical dimensions shown. The outside surface was left blank, and was tidied up once the main dimensions were hit.








Starting off with a length of 12mm bar, it was spot drilled and drilled to a depth of 0.525" with a 1/8" drill.







The drilling size for 5/16" x 32 is size J or 7mm. Normally this would mean making up another D-bit to give me the flat bottom to the hole after drilling, but in this case, I had a 7mm end mill, which I used to drill to a depth of 5/16". That saved me a lot of work.







The hole was the power tapped with the flat ended tap I had prepared earlier until it hit bottom.







The lead in was given a nice chamfer.







A needle body was screwed in to check for fit and depth. Perfect for what I want.







It was then parted off to a length of 1/2". This was to allow for a cleanup in later stages.







The previous operations were repeated until I had a nut made for each holder.







Now comes the time to shape up the outside of the nut.
A holding mandrel was made to allow me to get to all outside surfaces. The screw thread was a fair amount shorter than the internal thread on the part.







How the nut fits onto the mandrel.







The first job was to face the end until it was the correct length, 7/16". 







Skim up the OD to around 7/16"







Then it was time for some heavy stuff. I put a straight knurl on the end.
I have mentioned this before, and I use the generally accepted practice of straight knurls for undoing/tightening, and cross hatched knurls for gripping, as on a centre punch. But the choice is a personal thing.







A nice big chamfer on the end.







Using the same tool, I put a chamfer on the other side of the knurl and turned down the nut to a nice narrow profile.







Same tool again, and a small chamfer was put on the nut end.
By this time, the nut was really tightened onto the end of the mandrel, but with very careful use of a pair of pliers on the knurled area, they were loosened off with no detectable damage.







A little hand chamfering on either side of the 1/8" end hole, and the nuts were finished.







Getting there


Blogs


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## Deanofid (Mar 1, 2010)

Those knurled nuts and valves look top rate, John. 
Still with you, and happy for as many pics as you care to post.

Dean


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## Blogwitch (Mar 1, 2010)

Thanks Dean.

I have worked out only five more bits to go until the basic unit is ready to have gas to it, the needle, air control ring, diffuser screen and holding ring, and then of course, the jet, plus any special tooling to get the parts made.

Once those are done, then I will make a couple of right angled ends, a gas distribution block, and I haven't decided which regulator valve to go with yet, most probably the one I posted, as it looks a little less complicated and easier to make.

Unfortunately, lots of things to do this week, and I don't know whether I will feel like doing anything for a while, so it will all be as and when.


John


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## Blogwitch (Mar 1, 2010)

I started on the needle this evening, but didn't have the time to put things into practice, so the needle bit will be done in two parts.

This is the design stage.

I could in fact work everything out mathematically for making this needle, but at this time, I don't think my brain is up to it, and also, by doing it manually, it will show how to make a multi part needle. Most people will only be making one or two of these items, so this is an ideal way.

First off, I needed to find any sort of bar that is just smaller than the root diameter of a 6BA thread. This will allow enough room for the gas to flow into the bottom end of the valve and disappear up the jet. I found a short length of 2mm silver steel just perfect for the job.







From previous experience, I have found that a 10 degree included taper is just fine for this sort of control, where a needle is sitting into a squared off face. It could be made a lot shallower, say 5 or 6 degs, but then you end up with a very long needle, but much finer control, and usually a lot less robust. The one on the plans doesn't give the angle, but a quickie calc gives an included angle of 18.78 degs, which will, of course, give less fine control.
So I set my topslide over by half the included angle, that is 5 degrees.







With a razor sharp tool, and the lathe at 900rpm, I cut a taper onto the end of the bar, trying the gas inlet end of the needle holder onto the taper every so often until it sat about half way along the cut taper. Once that stage was reached, I marked up where it came to. The end of the needle should not end up sharp.







This is what it looked like, about half way along the taper. The taper length ended up at approx 1/4". As you can see, I am not working to decimal places here, near enough is good enough for this job.







By taking the needle and pushing it gently into position (I don't want to form the seat just yet), where it came out of the body was marked up.







The needle was then tried in all the other bodies, and as far as the old eyesight could tell, they were all exactly the same.







By making a near enough measurement, from tip to mark, and referring to my previous sketches, I was able to calculate the rest of the needle dimensions.







This is what the finished needle should end up like.
Unfortunately, making it is a little more difficult, as it is full of little traps for the unwary, and needs to be machined in the correct order to end up with a good needle.






So next time, I hope to be able to make eight of these items.


Blogs


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## NickG (Mar 2, 2010)

Blogs,

Very nice work and a very comprehensive write up and excellent pictures. Thanks for taking the time to do this, it's what the topic needs but I know it takes a lot of time up. I haven't been able to get on myself or in the workshop but thought I'd check in today. Just can't seem to find the time.

I like your method for making the tube spigot and will use that myself for future work.

Your crib sheet for the needles will also no doubt come in handy for a lot of people.

Thanks,

Nick


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## Blogwitch (Mar 2, 2010)

No problems Nick, you will get in there when the time and temperature allows. I am lucky in that I don't work for a living any more, and my shop is a constant 14 degs C throughout the winter, no matter what the outside weather is doing.

I used to have problems when using silicone tubing, of it tearing when using the sharks tooth type spigot, so I started to use this design.

It does have one drawback, when using it for higher pressures, it doesn't hold as tight as the normal sharp grippers, because unlike normal plastic fishtank tube, the silicone blows up, a bit like a balloon, but not to the same degree, and so when the internal diameter grows larger, it pops off. If that ever happens, all I do is to wrap one turn of thin plastic coated garden wire around where the recesses are on the spigot, and twist, then cut off the twisted end to a short length, two of those, and it will go nowhere, but it still won't tear.

John


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## Deanofid (Mar 2, 2010)

It's (they're) getting there, John. 
I was wondering what angle you would use for the needle. Thanks for the heads-up!

Dean


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## Blogwitch (Mar 6, 2010)

Sorry this hasn't progressed any. Even though you might see me online, I can't do anything in the shop at the moment.

Anyone who knows me personally, if I mention cold virus, will know why.

Normal service will resume as soon as possible.

John


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## Deanofid (Mar 6, 2010)

Glad you're able to check in with us, John. 
Hope you get to feeling better soon.

Dean


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## 1hand (Mar 6, 2010)

Blogs:
Hang in there buddy, our thoughts and prayers are with you.

Matt


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## Stilldrillin (Mar 7, 2010)

Thinking of you, and yours, John......

David D


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## Blogwitch (Mar 11, 2010)

Because I have been dragging my a**e on this post, someone who has been following along with it, has actually overtaken me and finished one off.

Over the last couple of days, we have been in PM contact, and he has shown me the great results. Not the right thing to do with me, as I will take advantage of the info I get.

He doesn't want to show his finished product until I get mine up and running, but under the circumstances, where mine won't be finished for maybe another week or so, and also because mine is a full warts and all build. He doesn't know I am doing this, but I have no qualms about forcing him out into the open, and showing what he has shown me.

[ame]http://www.youtube.com/watch?v=YnQ2H5_h2LA&feature=player_embedded[/ame]

He told me that this was without a proper regulator. With one, I reckon the results will be even better.

Well done Dean, come out and take a bow.



Bogs


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## Deanofid (Mar 11, 2010)

My dirty little secret is brought to the light of day. 
Nice of you John, putting some other guy's stuff in your thread.

FWIW, I made the D-bits same as John showed in this write-up. Ditto for the angle of the needle for the valve.  All worked as advertised.

Dean


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## SBWHART (Mar 12, 2010)

Great work Dean :bow: :bow: :bow: :bow: :bow:

Stew


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## Blogwitch (Mar 21, 2010)

Just a little more to add to the post, this time it is making the metering needle, and might be of help if anyone has to do one similar.

I rooted about in my stainless box until I had enough offcuts to do the job. I use stainless because it is slightly easier to get a decent finish than silver steel (drill rod), and of course the needles don't have to be hardened as they don't rub on anywhere, it is the gap around the taper that gives the control. You could use almost anything for the needle, as long as it will withstand the rigours of use. My bar is 1/8" ground stainless.

When cutting fine points such as this, you have to plan ahead, because putting the right cut in at the wrong time can cause failure, plus you need to get heavy cutting done while you still have the rigidity of the original material. Your cutting tool needs to be razor sharp. Mine looks to be all shapes, but the bit that does the cutting is sharp enough to shave with, and was dressed on the top face with an oilstone before starting the job.

The taper I wanted was set up on the topslide, and by using the topslide feed, I took a full cut to almost full depth. Then I was was left with a tiny skimming job to get to final size. If I had done it in stages, I would be losing the rigidity of the original material and the taper would be liable to bend and be ruined.
The black mark on the taper is a pencil mark to see if I was at the right size with the hole it would be going into.








Next came the plain portion of the needle, again this was taken down to size in one cut.







Then the area for cutting the thread, that was done in the same way, one cut. Mine was cut to 0.110", the correct size for a 6BA external thread, you would need to make this size for whatever thread you were using. Now normally at this stage, I would put in the runout groove for the thread to be cut, but going by experience, I know that if I did that, the part would break into two at that groove, caused by the cutting forces of the threading. So that will be left until after the threads are cut. 
Every operation moves a bit further along the needle length, and each operation is completely finished before moving onto the next. This gives you maximum support for the operations you are carrying out.







As you can see, I used a motley collection of bar ends, but it doesn't matter, because when the part is finished, you won't be able to tell where they came from.
These are now ready to have the threading done. So I need to get a bit of scrap bar to set my die up to give a perfect fit into the internal thread.






I will see if I can get a bit more done later, it all depends on when Ralph leaves. Friends always come before machining.


Bogs


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## Blogwitch (Mar 29, 2010)

I had to go way back to find this article, it is so long since I did anything with it, but I have now nearly finished the control needle and this is an insight into how I went about it.
For some reason some of my shots didn't turn out too well, but I will try to talk you thru them, and you will have to use your imagination. At one time, I would have gone back and set everything up, can't seem to do that nowadays.

So, as mentioned in the last post, I used the long redundant end of one of the made needles to set up the die for cutting the thread. I used the needle holder to make sure it was a snug, but not tight fit. The better the fit, the less work the sealing washer has to do.







You can't see the thread very well, but all the needles were power cut until the die nearly touched the shoulder on the needle. You don't want to go all the way to the shoulder, otherwise the die is liable to cut a taper onto the shaft, because of the built in feed taper of the die. That is a thing you don't want to happen.







The die was turned around in the holder, and set up to the same settings as before (counting the number of turns and part turns of the adjusting screw). The needle was then set up with the shoulder level with the collet nose (you would use the chuck jaws). So in operation, the die runs up and touches the collet before reaching the shoulder. By turning the die around (good quality dies only) you will get a full depth thread cut all the way along the length. Sometimes you get dies that have a taper lead in at both ends, if that happens to me, I grind the back side of the die down until there is no lead in taper left, and that ensures I get the full depth cut.







Again, I mentioned this in the last post. Normally for larger threads, I would put the runout groove in before threading, but when dieing down such small diameters, the forces involved would almost guarantee that the thread would break off before it was completed, so in this shot, it shows me putting in that runout slot. This cleans up the end of the shoulder and ensures there are no tapered threads at the very end. It isn't really necessary on this job, as I have calculated out that the threads should never bottom out, but old habits die hard, and besides, it makes the job look more professional.







All the needles were cut to length with a hand held cutting disc. I left a couple longer than the others, just in case a burner needs to be installed in a tight place. I suppose they could be almost any length.







The next job was to make up a few handwheels for the needles, so I straight knurled a couple of short lengths of brass, and drilled down the centre with a 1/8" bit. It doesn't look too pretty, but I am not worried, as you will see later.







Using the standard method for making multi parts like this, the bar was mounted into the RT, and using a 2mm stub drill, for rigidity, I drilled half a dozen anti heat transfer holes down as far as I could go.







This is what they look like from the end. Discs were then parted off these rods to give handwheels of 0.060" (1.5mm) wide.







Now you can see why I wasn't worried about the knurling. They are so narrow, all you can see is a bit of knurl on each one, and they look perfect, even though when all together on the bar, they looked terrible.







Because I am expecting to make a few more of these units, I am making custom holding jigs as I go along. These wheels need to be perfectly square to the needles, so I will make up a silver soldering jig to ensure that is the outcome.

You'll get a bit more when I do it.


Bogs


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## ksouers (Mar 29, 2010)

John,
Neat little trick with the handwheels. How thick of a cut off blade did you use?

Also, glad to see you back in the shop, always.


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## Blogwitch (Mar 29, 2010)

Kevin,

I used one of my standard sized 0.050" parting and grooving tools that I grind up myself. So it was just a matter of feeding 0.110" from the last cut using the topslide. Done in no time.

Still taking it very steady, I don't want to go hurting myself.


John


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## Deanofid (Mar 29, 2010)

Glad to see greasy fingers in your thread again, John. (Meaning, pleased you are out in the shop!)

This post ties up a few loose ends, for me, concerning the metering needles. They look very nice!
Glad to see someone point out a thread run off cut at the end of die cut threads. It does make a difference in appearance, and I think speaks of good shop habits.

Thanks for the new post! 

Dean


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## Blogwitch (Apr 1, 2010)

Dean,

Just taking things steady at the moment, but I have got a bit more done, not on the burner, but for the burner.

This is a little jig I made up. That is a 3" square in the background to show some sort of scale.

Front view







Back view







And this is what it is for. It is a silver soldering jig.
Because the disc is a slack fit on the shaft to allow silver solder to flow into the joint, it would be very difficult to stop it flopping about.
So this little thing holds the needle and disc nice and square and in the correct position to each other while I dab on a tiny bit of solder.
It is adjustable so that it can cater for different lengths of needles.
No use making a jig for just one, but for the quantities I expect to be doing, it is a worthwhile investment of my time.







The next time you see this it will be in use.


Bogs


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## SBWHART (Apr 1, 2010)

Hi John

I was wundering how you were going to fix those parts together, look forward to seeing them in use.

Cheers

Stew


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## Blogwitch (Apr 1, 2010)

Stew,

I had thought very early on about how I should go about fixing them together, threading, turned down shoulders etc. But this is more veratile, as the needles can be any sort of length, right up until they get joined, just hack it to the correct length and stick 'em together, no extra machining to be done.

I can use any sorts of short offcuts to make the needles out of, as long as they fall within a certain diameter, length and material type. In fact if it can be silver soldered, and 1/8" in diameter, it will do.


John


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## Deanofid (Apr 1, 2010)

That's a handy little jig you've made there, John. Holding things the way you want them for soldering is half the battle. This looks like it could be adapted to a number of uses.

Dean


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## Blogwitch (Apr 2, 2010)

Dean,

I could just have easily said that the bits were soldered together, but because this is a warts and all post, I am trying to show even tiny details, all because one person might be able to pick up on something and use it to help them overcome a problem.

Sometimes 90% of the job can be figuring out how to hold things to get the part made.

In fact, very soon, I have a special bit of tooling to make for my tailstock, so that I can get another job done on this build. As you know, I only have complete use of the thumb and forefinger of my right hand, and sometimes I have trouble getting my big fingers in to do the dastardly deed as the duff three are tucked into my palm and get in the way. So I am modifying a tool I found on Chris Heapy's site to allow me to get more feel on the end of my forefinger when drilling tiny holes on the lathe.

http://www.astronomiainumbria.org/a...anica/easyweb.easynet.co.uk/_chrish/plans.htm

Tailstock sensitive drill attachment.


John


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## Blogwitch (Apr 2, 2010)

Now to get onto silver soldering all the bits together.

When doing a small production job like this, I make sure everything is to hand and prepared for use. That way, you can get a bit of a rhythm going and the job gets done in no time.
The flux is prepared to get it to a nice runny mix, the silver solder wire has been wrapped around a drill bit to give me the correct sized circles to fit the job, and stainless implements and long nosed pliers for moving hot bits into the quench/citric acid pickle bath.







This is showing the very first bit to be soldered using the set up jig, no practice here, it has to work from the off.
What has been done is that the needle has been dropped into the jig, a tiny bit of flux put onto the top, and the disc has been pushed onto the needle. This ensures that there is flux down in the hole. Then another drop of flux followed by the solder ring.
No special torch used here, just a standard plumbers gas blowtorch played onto the needle just under the disc. I want this to get up to temp as fast as possible.







The first one done, as shown, the solder has stayed where I wanted it and flowed down into the joint (towards the heat) and formed a nice fillet underneath.







They were all very quickly completed. The jig turned black when I quenched it so that I could adjust for the longer needles.
That will be put with all the other bits I have made for this job, just in case I want to make some more.







A quickie clean up on the lathe to put chamfers either side of the knurl, and a fibre brushing on the buffing machine to clean out the knurl recesses.
This pic shows roughly what they will look like when finished. The needles were perfect length as I had designed them, and the o-rings collapsed really nicely to hold the needles in their set position, but still allowed movement with a little extra effort.







A bit more silver soldering now, to get the needle holders mounted into the main assembly.
I have mentioned this before, and Dean has made his without soldering, but I am a bit of a belt and braces chappie, and so everything gets stuck together.

So the first bit was to make some solder rings for the job to come. I wrapped it around an old knitting needle that was slightly smaller than the needle holder, and cut down the edge to form the rings. This will allow the slightly stretched solder wire to grip the holder by itself, and not be floating about as the initial heating is carried out. After the first heat, the flux will boil off and form a hardish crust that will then hold the solder in the correct position ready for more heating.







I started by getting as much prepared as I could, as I will be doing these in two batches.
A ring was put onto the holder, then flux was painted down into the main hole. After the two parts were assembled, a ring was put onto the other side and a tiny dab of runny flux painted onto each solder ring.







This is the first batch, they don't look very pretty, but once a bit of heat is on there, things will get a lot tidier.







As I work down the row with the torch, from left to right, the next one along will be warmed up and the flux solidified enough to hold things in place, ready for the main blast of heat. You can just make out where the torch is pointing, down at the base of the part. That will heat it up from the bottom upwards and as the flux and solder begin to melt, by capillary action, be drawn towards the heat and then will fill in the gap inside the joint.

This might seem to be like a load of bull-sh, but believe me, you can work out very accurately how much solder is required and where it will end up. I very rarely rod feed, it is just too inaccurate and wasteful for the sort of joints I want to produce.
With silver soldering if the joint is just filled, it cannot be made any stronger by piling on more solder, it just makes the job look unsightly and you also have to spend hours cleaning off the excess.

One packet of wire costing less than a pound has done all of the joints on this job, and I still have some left over for another job.







Job done, the flux has done it's job and the solder is exactly where I want it to be, inside the joint, not running all over the place as normally happens when you rod feed. Very little cleaning off to do.







After a few minutes in the pickle, I brushed one down with a fibre glass pencil. This shows how little cleaning up will be required.







So these will be left to stew until tomorrow, then I need to drill and tap for the jets, and then get another bit made, the air control ring.


Bogs


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## Deanofid (Apr 2, 2010)

That's a good bit on hard soldering, John. Many people find some mystery in it.

I see your fingers in the pickle. Are you using citric acid? It's what I use, but find it takes quite a while to do the job. Safe, though.

Thanks for the progress report. Nice write up and pictures.

Dean


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## Blogwitch (Apr 3, 2010)

Sure is citric Dean, last years lemonade. I must mix myself a new batch up sometime.

With the flux I use, I find that an hour is plenty long enough to clean things up.

There is no black magic involved with silver soldering, just keep it clean, get a good quality flux and use a good technique for heat control. By doing that, 99% of the time, you are guaranteed the right result, and that is no boast, anyone can do it. It is just like parting off on the lathe, follow a few basic rules, and it is just becomes another string to your bow.

I am going to try to get a few slow hours in today, but it all depends if we have visitors or not.

Have a good Easter break.

John


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## doubletop (Apr 3, 2010)

BogS

Good to be able to see how the experts do it. After my recent experiences I'd anticipate to end up with a brass blob on the end of the needle. However, thing are improving for me on the soldering front.

I'm finding that brass in the pickle is taking on a copper coating, My pickle has turned pale blue which I assume is copper sulphate from the boiler parts that have been in there. Do you have separate pickle tanks for copper and brass?


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## Blogwitch (Apr 3, 2010)

DT,

I am no expert by any means, it is just that I have a full understanding of the mechanics of the process, so if I follow the rules I have learned, things turn out well and as expected.

That coating is just a normal occurance with a citric pickle. It is a chemical reaction, and you will also find that any ferrous parts will get a copper coating as well. 
It very easily cleans off, and I will show how I do it in my next post. Most of it should wipe off with a cloth while it is still wet with pickle.

You seem to have got your silver soldering fairly well under control now, and as you proceed further, you will find things start to get a very lot easier. Getting the heat into the right position is one of the main criteria, and that can only come from experience.

Bogs


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## Blogwitch (Apr 3, 2010)

To carry on from where I left off on yesterdays post.

Straight out of the pickle and dried off. Most of the copper coating has been wiped off, except for where the flux had been at work, that is where there is an etched surface, so it will be embedded in a little. But more of that later, first off, I have a couple of machining jobs to do on them.








Using a 1.8MM drill (tapping for 8BA) I drilled down thru the previously tapped hole in the jet holder, into the needle chamber. If you didn't realise, without that new hole, the gas couldn't get to the jet.







Hole from above.







The tapped hole was then extended right thru.
That is all the machining done on this part now, so it is finished except for cleaning it up.







On the pigtail is a BRASS wire brush, this isn't as harsh as a steel one, so it won't wear away any of the material, just give the whole surface a good scrubbing. But as you can see, it gives a lovely brushed sheen, IMHO, much nicer on a job like this, rather than a high polish. Also notice the nice silver soldered fillets, no excess solder to be removed at all.
These only took about a minute each to get to this stage.

When using rotary wire brushes you have to be very careful with your safety routine, especially glasses. Razor sharp needles get thrown out in all directions at a very high velocity.

Another thing to remember is that you need to turn the brush around very regularly, because just by the action of holding the part against the bristles, it bends them backwards, and they lose their efficiency to clean very quickly. I turned mine around after doing each individual part.







All nice and clean, showing that nice soft sheen.







Built up, ready for the next piece, which I didn't have time to do today.
You can see the difference in finish between the two parts. They will all be matched up with regards to surface finish at the very end.







I'll see if I can get a bit more done tomorrow.


Bogs


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## Deanofid (Apr 4, 2010)

They look very nice, John. Good tip about turning the brass wire wheel. Funny, the things a guy never thinks about.

Dean


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## Blogwitch (Apr 4, 2010)

That's the advantage of using a pigtail Dean, it takes only seconds to flip the wheel around, I do the same with my buffing wheels as well. They last a lot longer and you always have an efficient surface to work with.

But I am always very wary of using wire brushes.

I was in the workshop at work many years ago when one of the machinists starting running around shouting his head off. He had been using a wire brush in an electric hand drill, and a piece had come off and embedded itself right on the middle of his eyeball, he wasn't wearing glasses. 
Luckily the first aider in there soon had things under control, three people took him to the local hospital, the driver, another holding his arms down, and the first aider holding his eyelids open and dripping emergency eyewash continuously onto his eyeball. That first aider saved the chaps sight in that eye that day. 
At the hospital, supposedly they used a large magnet to remove the spike, and in a couple of weeks, his eye was back to normal. He was very lucky indeed. If he had rubbed his eye with his hands, the eyeball could easily have been permanently damaged.

I occasionally get the odd piece embedded into my bare skin, that isn't very nice either.

In the UK, the cheapest place to get brass pigtail mounted wire brushes is here. The wooden hub can easily be drilled out a little so that it fits your machine.

http://www.proopsbrothers.com/acatalog/Online_Catalogue_Polishing_42.html

Safe buffing.


Bogs


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## doubletop (Apr 4, 2010)

A brass wire brush is the trick then. I assume its a pure brass brush and not a brass coated steel wire brush. I ask that because I picked up a cheap set of brass coated brushes recently and I'm sure that error could easily be made and a nice job messed up

And Proops; that takes me back a bit We'd spend hours rummaging through their place for a bargain in their place in the Tottenham Court Road. Just looked them up........



> _ Way back in 1946 members of the Proops family opened a shop on Tottenham Court Road, close to the major London shopping district.
> They traded in War Surplus items as well as many other clearance or job lot lines.
> 
> The principal products were medical equipment and 'technical' items from aircraft such as instrumentation and electrical components.
> ...


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## Blogwitch (Apr 4, 2010)

DT,

I've been using Proops for more years than I care to remember. They still attend most model engineering shows. Digging your way to the front is the usual problem. They still use the old system of giving you a plastic box to use as you work your way around the massive stand, dropping all the cheapo bits in, and tallying up when you think you have got everything you want. Then as you are leaving, you notice something else you fancy. :wall:

They do have some real tat, but things like their cheapo stainless dental probes and wax carvers I find perfect for silver soldering work. They are also about the only ones now selling the mixed packs of Whiston's steel, 10KG for 15 squid. Rather expensive for the mainstream machinist, but perfect for the average chappie in his workshop who wants the odd bit of steel now and again.

I can root thru their site for ages, ordering those little bargains and normally ungettable bits.

At one of the shows, I remember buying 100 squids worth of metric taps. They must have got a job lot somewhere and they were real top quality, every main size from 2mm to 12mm, 50 pence each. I am still using some of them nowadays, and everyone at work got a set as well.

They are pure brass wire wheels BTW, and do a wonderful job. Their pigtails, soaps and buffing mops are a bargain as well, if you want to use one end of your offhand as a buffing machine.


Bogs


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## doubletop (Apr 5, 2010)

BogS

My experience with Proops was in the radio/electronics field as my background is electronics, and now IT. I thought they'd long gone but I see they have been bought out and now trade from Leicester or there abouts. They probably couldn't afford the rent in Tottenham Court Road these days, funded by low end second hand goods.

anyway we're way off topic here. So back we go......... By way of an experiment I tried out one of my "brass" brushes tonight. They make a right mess!!! so a proper *brass* wire brush is the order of the day

regards

DT


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## xo18thfa (Apr 5, 2010)

I've tried to find it, have you drilled the jets yet?


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## Blogwitch (Apr 5, 2010)

Bob,

I haven't got to the jets yet, but after I have made the air control sleeve, that is the next job to be done.

The problem is that I have to make a sensitive drilling attachment for my lathe to drill out the small main bore in the jets, and also a holder for turning the jets to length and holding them whilst drilling the main bore, only then can I actually drill the jetting holes in the other end, and that will require a jig making to align everything on the high speed drill so the holes are true and centrally located.

One thing leads to another, if the job is to be done correctly. Also, because this job might turn out to be a continuous little job for me, everything needs to be made to last. 
For making a one off, you can usually cobble something together to get the job done, but for making multiple parts, I would never go that way.

Bogs


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## NickG (Apr 8, 2010)

Bogs, thanks for the updates, lots of good tips in there. Will be getting a brass wire brush, nasty story about the accident but worthwhile sharing.

Good tip on the thread undercuts for small diameters too.

Thanks,

Nick


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## Blogwitch (Apr 8, 2010)

Sorry this post has stalled yet again, but more pressing matters are being dealt with.

But it shouldn't really matter as this is being written as a reference article than a build one, so time doesn't come into it.

Glad you liked a couple of the tips Nick, and hoped you enjoyed the cramped lifestyle of my shop with three of us in there. As I have always said, I like to be able to have everything within easy reach. What I never mentioned is that you can almost do it without moving.

I forgot to give you one of those scraping tools, but I will send you one when the burner is eventually ready.

Bogs


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## NickG (Apr 13, 2010)

Bogs,

It was a pleasure to meet you and be shown your shop and some of your work. I wish I'd really spent the time up front to sort my workshop out like yours. 

Thanks, very much appreciated. Enjoying this thread and don't worry about stalling, my poppin has been going since the end of January and there is really no end in sight at the moment if I'm honest. If you feel you have to do something it's not a hobby any more in my opinion so just go at your own pace and do bits and pieces when you feel like it and time permits.

I forgot to ask, I prefer your brushed surface finish on the valve work etc also, but is there anything you can put on it or brush it with to preserve that finish? I usually just sort of polish my stuff with oil to attempt to preserve the finish but for the finish you require would that make it too shiny? For my aluminium I used paraffin or white spirit which gave a more satin type of finish.

Nick


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## Blogwitch (Apr 13, 2010)

Nick,

I have mentioned this over a few years now.

I did some experiments with a piece of brass that I had engine turned. I tried all sorts of laquer coats to keep the shine but only one ever shone thru (excuse the pun), and I still check it every so often, and it still hasn't deteriorated one tiny amount.

Many years ago, I bought a couple of tins of fixing laquer that is used to apply over wax rub down letters that I used to use on my model boats, to stop them lifting off the surfaces they are applied to. The coat goes on super thin when sprayed from a distance and there is no sheen that is physically detectable, it just seems not to be there. I think mine was a satin sheen, but I can't check it out at the moment as it is buried in deep storage at the back end of my shop. This is the stuff

http://www.artistmaterial.co.uk/acatalog/Letraset_Fixatives.html

and another with different ranges

http://www.wheatsheafsales.co.uk/acatalog/Fixatives.html

I must get around to spraying one of my engines over when it has been repolished, only then could I give a definite result.

But I do treat my engines with a spray and polish with 'Mr Sheen', and that definitely keeps them spick and span a lot longer than normal. I wouldn't try either of these things on a 'heated' engine though, as I am sure it would just burn to a brown chocolate type of surface.

John


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## NickG (Apr 14, 2010)

Bogs,

Thanks for the info, it's cheap enough that stuff too. My engines usually look ok when I've first finished them but once built most of them are too fiddley to start polishing unless you take them back to bits.

Nick


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## Blogwitch (Apr 14, 2010)

Nick,

I managed to check my two tins this morning, and they are both gloss.

John


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## metalmuncher (Apr 16, 2010)

Hi Bogs


I'm new to this site have been lurking, been watching what you're doing and have bought the plans to make a burner. I'm a member of another site to do with toy engines like mamods and and found a post for a cheap gas tank and burner. Its on ebay in Germany at less than half price of anything you can buy in the U.K.

http://cgi.ebay.de/Tank-Brenner-5...Bausätze?hash=item1c08135cbb


I purchased one and it arrived this morning very good quailty and runs my stirling engine ok. Got to be worth a punt just for the tank at £20.00 including postage. I didn't want to take anything away from your build just thought members would like to be made aware of whats out there. Metalmuncher.


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## Blogwitch (Apr 17, 2010)

Unfortunately MM, it seems that link is no longer available.

I have no problems at all about people showing their fixes and sundries, it all adds to the mix, as long as it doesn't take over the post.

Personally, without seeing it, I can't imagine a refillable gas tank for that price being built to the exacting standards required by UK legislation and insurance cover. 

You do have the necessary third party insurance cover, don't you? If you don't, I would recommend a 5 million squid third party, as that is what most local councils are demanding for public liability now.

It isn't the cost of building the tank that is the problem, but the cost of the special filler and discharge control valves, which should be specifically for gas control, not steam (that pair would normally cost at least 20 squid by themselves), and the time taken to carry out the necessary high pressure testing of the tank.

If it didn't come with the relevent documentation certifying conformity, it is illegal for you to operate it in a public place (see insurance cover above), and that means in your own home if anyone else is in the building or grounds. They don't mind you hurting yourself, but if it means someone else might get injured (including your family members), they take a very dim view of it, and the book would fly if they got wind of it.

But each to his own I suppose, if you want to take the risk.

Now a little about this post, it hasn't stalled, but been put onto the back burner while a major building project (for me) on the back of my house is brought to stage where it is weatherproof, while this good weather we are having holds out. A couple more days and I should be ready to get back into the shop and continue on this deep insight post.

Bogs


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## metalmuncher (Apr 17, 2010)

Hi Bogs Sorry the link didn't work, just so you know what i was talking about heres a picture hope it works.


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## Blogwitch (Apr 17, 2010)

MM,

That is basically just a stripped down commercial 'cooks' mini blowtorch with a small extension tube fitted, not a proper rechargeable gas tank in the sense of the word when referring to steam raising gas tanks and burners.

http://www.cookware-online.co.uk/sh...hen-craft-black-cook-s-b-256802.html?shopping

As far as I can remember when I was experimenting with those blowtorches, they don't have an actual jet in the burner nozzle, but a tiny ceramic porous disc that clogged very easily when run on the wrong type of gas. I think they are designed to run on a pure butane, which is the gas used for cigarette lighter refills, not the normal butane/propane mix as used in plumbers gas torches and most steam raising burners, which runs decidedly hotter.
I found the only way to successfully clean the diffuser disc (about 2 - 3mm diameter) was to reverse it in its mount and hope the gas pressure would blow away the debris. That worked about 50% of the time. I gave up on them after a couple got clogged up and couldn't be cleaned out.

Good luck.

Bogs


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## xo18thfa (Jun 7, 2010)

Just happened to find this very interesting way to make jets for mini gas burners. This is very do-able. I think we engine builders should hang around the clock and camera makers a little more.

http://www.deansphotographica.com/machining/projects/burner/burner.html


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## Blogwitch (Jun 7, 2010)

Bob,

That is Deans own post, and shows how to build the one I am doing. I introduced his vids a while back in this post.

Due to family and health reasons, almost everything I am doing has been held up, I can't get into the shop at this time, but this post will be restarting again soon (hopefully) and I will be showing how to make the jets from the solid and also a special small peck drilling tool that fits into your tailstock.

Bogs


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## xo18thfa (Jun 7, 2010)

I understand Bogs. Thanks for your postings and I look forward to seeing your process.

Bob


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## Deanofid (Jun 7, 2010)

Bob, and John;
I had figured on putting that little jet bit up here on our forum, but I wanted to wait to see John's tutorial
on drilling these tiny jet holes. I'm sure I will find it interesting, as I do with most all of John's projects.

Bob, this clock and camera guy here started out in a welding/machine shop. You make a good point.
We can learn from all the various trades!

John, hope things settle down to a nice, even and steady flow for you and Mal. Will be great to see some
more of your shop kinks and tips when you can get to it. 

Best regards,

Dean


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