Mini gas burner
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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
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
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
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
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
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
steamboatmodel
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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.htmBlogwitch said:
Regards,
Gerald.
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
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
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
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
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
Cheers for the C-o-C. Picture is worth 1000 words.
Nick
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
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
Blogwitch said:
I think it's this one but I can't see it http://www.homemodelenginemachinist.com/index.php?topic=1454.0
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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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