# Slightly Loco



## shred (May 19, 2008)

I decided I wanted my next engine to be able to move itself about. Long story short, I ended up finding the plans for a tiny narrow-gauge geared live-steamer that will run on O-gauge track and decided to give it a go. Turns out the plans are in metric and I'm not. But my original plan is essentially to leave the metric dimensions more or less in place and make a metric model with imperial holes. 

It's never quite that easy.. it'll be an interesting challenge.

It's only the second day and my plan sheets are already covered in scribbles, noting changes from one place to another. It doesn't help that I'm also modifying the design somewhat and the gears I have on hand aren't the same as the plans call for.

I've already broken one 2-56 tap and screw. The first attempt to remove the broken tap involved soaking the part in muriatic acid, based on some advice I found on the internet. That worked very rapidly.. at eating away the aluminum. Five minutes later the part was 80% of it's starting size and it was even odds if the tap would dissolve out or the aluminum would dissolve around it first  So I made another part and promptly snapped a cap screw off in it. Went back to the internet for advice and spent most of the afternoon trying to Alum it out to no avail. I finally drilled it out very slowly with a carbide PCB drill and retapped.. slightly off center.  Oh well, I think I can cover for it later.

Here's the progress to date-- one running plate, two side frames, two end beams, eight bushings and 4 axles (the gears I didn't make). It's already an unholy mix of metric and imperial that will probably have Marv reaching for his largest mallet.  --the basic measurements and holes holding things together are even metric values-- the holes and screw sizes themselves are imperial and the axle hole spacing is determined by the gear train and isn't a convenient number in either system. Some of the other holes are spaced imperial so I can bolt things on later made on the manual machines...


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## DickDastardly40 (May 19, 2008)

shred  said:
			
		

> IWent back to the internet for advice and spent most of the afternoon trying to Alum it out to no avail.



I've had success with Alum on a broken tap in brass but the process took days not hours. That said I don't know if I got the mixture strength correct etc.

Good luck with the rest, looks good so far. If you hadn't told us about the problem we would never have known..

Al


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## SignalFailure (May 19, 2008)

Nice start Shred! Are the plans online somewhere or did you buy them?


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## Circlip (May 19, 2008)

You did get the mix right Al, Alum is a slow working process, not sure of Its caustic properties in aluminium though. I remember vaguely trying to dissolve/loosen a broken stud in a motorcycle bit and I think it got a bit messy using Alum. OK though on CI and Brass. Regards Ian.


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## Speedy (May 19, 2008)

SignalFailure  said:
			
		

> Nice start Shred! Are the plans online somewhere or did you buy them?



would like to know also. 
looking good, keep pics coming ;D


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## shred (May 19, 2008)

The plans are available online. Search for 'cracker' and 'live steam' and they should turn up. It's 6 pages of drawings and nothing else, so you get to be creative trying to figure out what goes where and when, including all the plumbing (there are some much more detailed free plans for different engines available. 'Idris', for one that looked much better documented). I know few live-steamers to pester for advice later on.

For even more mixed-ancestry fun, the 'Cracker' plans are loosely styled in the British/European style, although the original prototype was a very short-run US industrial loco, the 'Byers'.. I believe there have been more designs off it than original examples, Cracker and Cricket (also worth a search), to name two. I'm going to build mine more in the US style with a proper roof, though I'd hate to be the engineer that shares the cab with most of the boiler.






The alum seemed to be doing nothing at all after several hours at simmering temperatures besides lightly etching the aluminum, so I decided to try the carbide drill-- at least that would expose more surface area to be attacked if it didn't work.

More build notes:

The gears are replacement RC car pinion gears-- available locally and ~$3 each. 12T and 35T were the smallest and largest sizes available in 48P at the hobby store, for an almost 3:1 gear ratio. Once the store gets more in, I'll add a gear to the other axle. They're only on there at the moment to test fit and mesh anyway.

Another change I did was to thicken up the frame plates-- the plans call for 1.5mm (1/16") brass, but being short on that, I switched to 3mm (1/8") Al. 1/16" felt kinda flimsy anyway. That cascaded changes into the beam ends, axles and bushings. [edit: it also prevents Gauge-1 operation with longer axles unless you thin the frames]


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## SignalFailure (May 19, 2008)

Ooops.... I've already got cracker.zip and the drawing for Dave Watkins' Idris.

Here's a video of Cracker built by 'Havoc'...

http://media.putfile.com/eerste-rit

...and here's an 'Idris' variant...

http://img.photobucket.com/albums/v453/bouser/Jack White/DSC02364800x688.jpg


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## Speedy (May 19, 2008)

that vid was cool ;D

anyone have links to the plans? I searched but no plans are coming up. :'(


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## dave e (May 19, 2008)

I found the plans at http://home.iae.nl/users/summer/16mmngm/Articles_htms/Cracker.htm


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## agr (May 19, 2008)

The plans and construction "manual" for the De Winton "Idris" are available on 

http://www.davewatkins.pwp.blueyonder.co.uk/steam.htm in about the 6th paragraph


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## Lew Hartswick (May 19, 2008)

shred  said:
			
		

> I've already broken one 2-56 tap and screw. The first attempt to remove the broken tap involved soaking the part in muriatic acid, based on some advice I found on the internet. That worked very rapidly.. at eating away the aluminum. Five minutes later the part was 80% of it's starting size and it was even odds if the tap would dissolve out or the aluminum would dissolve around it first


I don't know where you got that peice of bad info. but it's suppose to be NITRIC acid. Ive done it 
several times back a few years ago at the university. Getting Nitric acid may be a problem to the 
general public. Have any connections at a university chem dept.?
  ...lew...


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## shred (May 20, 2008)

Lew Hartswick  said:
			
		

> I don't know where you got that peice of bad info. but it's suppose to be NITRIC acid. Ive done it
> several times back a few years ago at the university. Getting Nitric acid may be a problem to the
> general public. Have any connections at a university chem dept.?
> ...lew...


Dad's a chemistry prof, but a thousand miles away. Several places on the net say muriatic is ok .. don't believe them. (I checked first because I had vague memories of creating hydrogen gas via acid and aluminum foil as a kid)

Thanks for the video-- I hadn't seen that one. I note that engines of this sort are sometimes known as 'piddlers', due to the water trail they can leave, so you might not want to run one across momma's new carpet.

Anyway, I got the wheels made tonight. I wanted to use a profile tool to cut the tread profile so that was a good excuse to play with my rarely used T&C grinder. The form tool worked ok (I ground it slightly wrong, though usable), but chattered like mad (I told my GF "how else did you think they get the screeching into train wheels? ). Part of the problem is I roughed out the 4 wheels separately, then returned them to a mandrel to profile with the form tool. That didn't work so well because trying to feed through the chatter just made them spin on the mandrel. Were I to do it again, I'd think about cutting all the wheels onto one bar, profiling them and then parting them off, or making a form tool capable of doing the roughing as well.

In theory, the long axles allow wheels to go on the outside for gauge 1 track and on the inside for gauge 0 track, but note thick side rails make that difficult.


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## bigsteve (May 20, 2008)

You can get pure nitric acid in pretty small quantities from Sigma-Aldrich (http://www.sigma.com). You have to register and be approved before they will let you order anything, but I think it is no problem getting approved (I'm a chemical engineer, and was approved through work, so I'm not completely sure on that).

You can also order somewhat dilute (~70%) nitric acid from http://www.sciencecompany.com - $22 for a pint, $33 for a quart. There is a hazardous material charge added to the price, supposedly, and it will only ship via ground (I'm sure there is a similar company in Europe that everyone over there could use).

A word of warning with nitric acid - it is some nasty stuff! Do not store it near other acids or lead-acid batteries (the vapors will react). Like all acids, if you want to dilute it, add small amounts of acid to water (not the other way around!), and stir it, allowing it to cool before adding more acid. Wear rubber gloves when handling, ensure plenty of ventilation, and wear full goggles or a face shield. Also, have a big box of baking soda nearby to clean up spills.

I would also look for some disposable plastic pipettes for dispensing the stuff, instead of trying to pour it out of the bottle.


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## shred (May 24, 2008)

While not distracted by speed-builds of finger engines, or monowheel cycle web pages, I made a few parts for the Loco wobbler engine. Of course, right after I built the standard I realized why the standard is drawn like it is, and not as I made it.. ah well, I can fix it later, so no harm done but a little extra shop time. Chalk it up to a fit of reverse-metrification blindness.  

Other notes: I'll probably have to redo the piston. That was a practice piece that turns out to fit well, but I don't think drill rod and live steam get along well long-term. The standard, as I note, needs to be redone to fit in place of a frame bushing (that bit of cleverness in the plans escaped me until now). I made the cylinder out of one piece of brass versus the much thinner-walled tube-and-endcap with soldered valve plate in the plans. Shouldn't make much difference one way or the other-- the blind hole required me to make up a D-bit reamer to finish it up, but I can skip soldering anything a while longer. The bore and stroke are very similar and I think this will look a little more like the original, with a big vertical steam engine on the side.

For the 'what order do I do things in?' thread, think about this piston-- lots of ways to make it, but it can get ugly if you get the ops in the wrong order, especially the parallel flats with a perpendicular crank hole (the thin sides are rounded at the piston diameter so the cylinder extension acts as a trunk guide)

- Roy

And for those that like to contribute-- here's one I'm idly pondering. The wheels (26mm x 6mm or ~1" x .25", 1/8" axle, flanged train-style, as seen previously) are drawn with no means of attaching them to the axles. I had originally planned to use loctite to fix them in position, but I'm liking that option less now. So-- shallow-angle-drill for tiny setscrews from the back? Affix to shaft collars? Bore and redo the hubs? Stick with adhesives? Other ideas?


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## SignalFailure (May 25, 2008)

shred  said:
			
		

> The wheels (26mm x 6mm or ~1" x .25", 1/8" axle, flanged train-style, as seen previously) are drawn with no means of attaching them to the axles. I had originally planned to use loctite to fix them in position, but I'm liking that option less now. So-- shallow-angle-drill for tiny setscrews from the back? Affix to shaft collars? Bore and redo the hubs? Stick with adhesives? Other ideas?



AFAIK they're usually taper-pinned and glued but as there won't be much load I guess grub-screws would do (with a dimple on the axle maybe?).

Nice work on the cylinder


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## shred (May 28, 2008)

Taper pins I could maybe do, but they might be very fiddly to install since the wheels usually go on the inside of the frame.

Anyway, on progress, I got the rest of the wobbler engine built and somewhat running on air (photos & video later), but along the way found another bug in the plans, or at least how I read them-- Sheet two shows a couple holes in the Port Block; one either side of the crank hole that appear to be there to bolt the port block to the frame, and my initial plan was to tap the frame... You can see the un-tapped holes in the frame shots above immediately beside one of the center bushings.

But.. there's only 1mm or so clearance for bolt heads with the crank in place.. that's not going to work. Time to think of a plan 'B'.


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## shred (May 28, 2008)

Here's the video of the wobbler engine running, on the bare frame with about 10 PSI air.

As you can see, I solved the clearance problem with some countersunk holes and flat head screws, but as I'm not liking those, they'll have to be replaced sooner or later. Sorry about the lack of light... seemed bright enough in there for me.

[youtube=425,350]Z1Rc9fgv-xg[/youtube]

Note, if your wobbler only runs one direction and with the spring really loose, you may have the exhaust hole drilled in the wrong place. If it's not off by much just enlarge it a little. Makes all the difference in the world. :


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## SignalFailure (May 29, 2008)

Looks pretty smooth, nice one!


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## rake60 (Jun 4, 2008)

shred I love slow engines.

I have never seen a wobbler running that slow.
Great Work!

Rick


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## shred (Jun 4, 2008)

rake60  said:
			
		

> shred I love slow engines.
> 
> I have never seen a wobbler running that slow.
> Great Work!
> ...


ok, so I'd better confess before everybody else with a wobbler feels inadequate  I cheated a little.. I filmed it at 300 frames per second as opposed to the usual 30, so the video is effectively running ten times slowed down ;D ;D I was trying to figure out what the hitch at the top of the stroke was caused by, thought the video was cool and waited to see if anybody noticed the unusual slowness of a 5/16" bore/stroke wobbler..


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## rake60 (Jun 4, 2008)

Hey, never give an inch! LOL

I was convinced!!

Rick


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## nkalbrr (Jun 11, 2008)

For the wheels try O guage one made by Lionel, MTH or Weaver. They have a large flange . O scale flanges are more prototypical and don't give you the fudge factor


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## shred (Jun 14, 2008)

nkalbrr  said:
			
		

> For the wheels try O guage one made by Lionel, MTH or Weaver. They have a large flange . O scale flanges are more prototypical and don't give you the fudge factor



Do I want a fudge-factor? Seriously. I made some wheels out of 1" steel bar I had handy, but I had to trim the suggested flanges even more.. I think they specified 26mm on the original plans and it's a bit tricky to get 26mm out of 1" stock  I've never run trains on O-track (long ago I had an N-scale setup), so I'm pretty clueless in that regard.

Btw, for anybody curious, the loco is on hold at the moment.. I'm just not excited enough to work on it when it's 100'F in the shop as it has been lately.


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## nkalbrr (Jun 14, 2008)

I just took some measurements(Cracker in parenthesis). The plans for the Cracker are metric . The dimensions are from a Weaver manufactured car made in the great state of Pa. Axel .093 (0.118 3 mm) outside diameter .960 (1.024 26mm) inner .709 (0.866 22mm)from hub to flange .154 (.197 5mm) from inner wheel -wheel 1.041 (1.102 28mm) Axel length 1.790 (1.185 47mm). the tread profile looks to be the same angle.The measurements may vary from manufacturer to manufacturer, but as you can see it's close like handgrenades and horseshoes


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## shred (Nov 24, 2008)

Those of you that have been paying far too much attention to my whereabouts know I was out of the model engine work for a few months. I'm back now (34th in the world thankyouverymuch) and ready to hack away again.

The Slightly Loco build was wrested from the Forces Of Entropy and is under way again.

I got by the plumbing store on Friday and spent part of the last two days boilermaking. If Firebird is making a 'small boiler', this is a 'tiny' boiler, or maybe even a 'micro' boiler. The outer shell is 1.25" tubing and the whole thing is about 88mm long.. Metric plans and imperial stock and tooling is such fun. :

All that's left is to solder it up and pressure test it.


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## J. Tranter (Nov 24, 2008)

Are there plans for that boiler you are making? I would really like to see them.
John T.


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## shred (Nov 25, 2008)

The plans for 'Cracker', which this is a variant of are on http://home.iae.nl/users/summer/16mmngm/Articles_htms/Cracker.htm
I have taken those, plus Tony Bird's build notes (very nicely done) and mixed in a mash of my own ideas and tempered by the material I can get and tools I have. 

The basics on mine are-- 1.25" (nominal) type L copper pipe x 85mm for the main barrel (type M is probably OK, but I went with overkill). The smokebox takes up the front 20mm or so of the barrel (I have half a pipe coupler over it for looks and to provide a recess for the smokebox door), so the boiler section is about 65mm long. There's one flue of 3/8 (nominal) pipe at the bottom of the boiler. Bushings for a steam dome and filler valve. Butane fired.

Instead of silver soldering the boiler I spent today making a pressure-test pump along the lines of Dick Summerfield's plans and silver soldered a lot of that to get practice with the new Cd-free solders. Yeek.. I'm not used to the bright-orange heat this stuff requires. Must remember to order some of the bad stuff before they ban it completely (it's already illegal to sell Cd-bearing solder in this town ???)

Pretty basic plunger-pump, but it should get the job done.. if I can manage to hang onto the frackin bearing balls long enough. I started with 4, need two and only have one left :-\ Two are somewhere in the shop debris, no doubt far under something inaccessible and one is locked in a mistake of a part (mental note; do not tap 1/4" balls into blind 1/4" holes and expect them to come out again, ever... De-metrification in my head and not writing it down got me on that one).


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## Macca (Nov 25, 2008)

This is fantastic.
I must have missed this thread earlier, but am now ravenously devouring all the info I can find on both cracker and cricket.
Before I saw this, I didn't have any interest in model locomotives, but I now have another thing to add to my list.
All I need to do now is find a few extra hours in the day.


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## Powder keg (Nov 25, 2008)

This is looking pretty neat Shread. Keep up the good work. I've alwayse wanted to build the Fizz Wizz car;o) Maybe this winter?

Wes


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## shred (Nov 25, 2008)

Macca  said:
			
		

> This is fantastic.
> I must have missed this thread earlier, but am now ravenously devouring all the info I can find on both cracker and cricket.
> Before I saw this, I didn't have any interest in model locomotives, but I now have another thing to add to my list.
> All I need to do now is find a few extra hours in the day.


Me too. Beyond a train set as a kid and a healthy interest in the full-size units, I've not the patience or time to build and run a serious live steamer, but this will run on O-gauge track, and I could probably stretch my interest enough to get a loop of that around the tree  I'm considering some optional 'road wheels' too, but don't know if's going to have enough oomph for that.

One good resource for little live-steamer info is the 16mmngm modelloco16mm yahoo group-- that's where I found Tony's Cracker writeup.

I'm going a little light on the details, since boiler construction is covered so well over in the Small Boiler thread, but if anybody has more Q's or wants to see more pics, let me know.


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## shred (Nov 27, 2008)

I think I'm getting the hang of the Cd-free silver solder now. When you can see what you're doing by the light of the workpiece, you're just about there 

It turns out my silver soldering is far better than my plumbing. 

I got the boiler soldered up last night and it's pressure-testing now. Spent a few hours looking at one piece of 1/4" copper tube and one piece of 1/4" plastic tube and trying to figure out how to join them together... $1.50 at the hardware store is the easy answer, but... they're closed today..  so I soldiered on with what parts I had. That turned out to be a problem. I figured out a mishmash of parts that got me there and made a few adapters, but all the screw joints created a leaky mess, so I had to go chase around with the teflon tape to seal them all up. I used a small valve to convert some odd pressure fitting to 1/4 NPT (the mating part if you look closely is an air tool fitting drilled out and soldered on-- I discovered too late my 1/4 NPT tap had run off and had no desire to learn to single-point NPT at the time), but turned out to be useful too; the pump check valve leaks enough that I had to use that valve to shut off the backflow once I reached pressure. The pump otherwise worked surprisingly well and can generate plenty of pressure.

There's still a tiny leak in the plumbing somewhere and I suspect the valve since nothing downstream is at all wet.. after 15 minutes the pressure has dropped 5 PSI, but there's no water evident anywhere around the boiler and it holds 80 PSI without objection.


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## Macca (Nov 27, 2008)

That's great shred! Did you have a link for that pump? I tried searching for it but all I could find were sites promising to (quite painfully I would imagine) increase the size of my manhood.


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## shred (Nov 27, 2008)

found it in the [modelloco16mm] Yahoo group (btw, that's where I found Tony Bird's writeup vs the other group I mentioned). As usual, it's a metric plan, but doesn't take a lot of work to adapt to imperial and is extremely tolerant of design modifications. I've attached the version I split to make it easier to print.

The only issue I ran into was using 1/4" balls. Were I to do it again, I might get 3/32" or so, so I could use a 1/4" endmill to do the flat-bottomed holes. The other mods I did were to use one piece of 3/8" drill rod for the piston and chrome steel balls since that's all that was available locally-- for occasional use they're ok, but you have to fish themout and WD-40 them right away or they'll rust. You'll also note that my piston cylinder is much shorter than the plans call for-- I had a piece already bored for a nice slip fit onto 3/8" drill rod in the junk box and it works fine.


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## shred (Nov 30, 2008)

Not as much progress on the loco as I was hoping for-- the safety valve is on hold until I get proper bearing balls, and I got a new idea for the filler valve (Goodall style) that will require a trip to the hobby store tomorrow for some silicone tubing, but I did get a few things done-- started a steam-dome cover, banjo fitting for the filler/steam dome (which will need to be redone), temporary smokebox door and stopped some pesky squirrels from chewing the bottom off my birdfeeder ;D


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## J. Tranter (Dec 2, 2008)

Since I saw this thread I have been wanting to build one. I have some questions if you don't mind.
How did you build the steam dome? How is the smoke box door attached? And can you show more pics. of the build process on the boiler that is what I'm having more trouble with.
thanks for all your help.
John Tranter


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## shred (Dec 3, 2008)

J. Tranter  said:
			
		

> Since I saw this thread I have been wanting to build one. I have some questions if you don't mind.
> How did you build the steam dome? How is the smoke box door attached? And can you show more pics. of the build process on the boiler that is what I'm having more trouble with.
> thanks for all your help.
> John Tranter


No problem with the questions. I'll dig around and see what more pics I have on the boiler build. 

As for the steam dome, I just remade that with a banjo-bolt fitting below a filler-valve. In the plans, the front bushing is used for the fill valve, but I wanted to put a safety there instead. The rounded dome cover is just a 1/2" copper pipe cap I annealed and hammered into dome-shape with a spherical doming punch and block (you can still see part of the 'nibco' stamp on it ). I cleverly took the photo so it looks like it's attached, but really it's just sitting over the safety bush. Once I get the plumbing run from the banjo bolt, I'll file it to shape on the bottom and drill the top to fit the filler.

The smokebox door is just a light push fit into the front of the smokebox. I plan to redo that as well-- I had some 1.5" Alu bar in the lathe and whacked it out just to have something to fill the hole while I did a steam test on the boiler. To remove it, I remove the smokestack and the smokebox (those aren't soldered yet) and poke it out.


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## shred (Dec 3, 2008)

Here's more on building the boiler. Here's how I did the end plates:

I probably did these in an inefficient manner. Since there's no central hole, I formed them without holes, then drilled them for the flue after they were formed. In hindsight, it might be better to drill a hole in the flue area and use that to mount them to the forming mandrel with an off-center mount screw to avoid some of the faffing around with a c-clamp I had to deal with. Anyway, here's what I did, starting with a foot or so of 1-1/4" copper pipe:

First I bandsawed a short length (~2") off the end of the copper pipe (if the pipe wall thickness is enough for end plates, otherwise get some flat stock of the right gauge), then sawed that into two half-pipes. Annealed and flattened those into rough squares. Marked out a circle the diameter of the tube ID plus 1/2" to give 1/4" flanges, then rough sawed to that circle. In retrospect, I should have rough sawed a lot closer. I just kinda knocked the corners off the squares which meant I had to do more trimming later during forming.

Then I made up a forming mandrel out of 1.5" Alu bar I had in the short-ends box. Steel or something tougher would probably be better, but the Al worked. You can see the mandrel in the lathe chuck in the 2nd picture, but most of the time I used it in the bench vice, so I thought milling the reverse end into a thick rectangle for ease of gripping in the vice was a clever idea. The front end was turned to the ID of the tube minus two thicknesses of the end plates.

I then clamped the rough flat circles on the forming mandrel with a C-clamp and started tapping the copper edge down around it to form the end plates. I annealed a few times along the way and after the shape got close and the plate didn't move so much, skipped the clamp and just held the former in the vice. After I had two plates looking like the first picture, I set up to clean them up in the lathe.

For the lathe work, I used a variation on Bogstandard's 'friction turning' method for flywheels posted elsewhere here-- I put the mandrel in the 3-jaw, the plate on it, then a short length of scrap rod with both ends cleaned up and a center hole in one and masking tape on the other, slid the live center up tight to hold everything, and by taking light cuts, trimmed the end plates down to a light push fit in the tube and cleaned up the ends. That setup is in picture #2

(btw, I found some miniature boiler test-to-destruction results showing that in this size boiler flanged plates aren't strictly necessary for full strength, but I wanted to try it anyway)


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## shred (Dec 3, 2008)

Here's drilling the boiler tube. Not much to say except the step drill works remarkably well. Mark on the drill with a marker the step(s) to stop at and drill away (well, pop and drill a pilot hole first). I did the drilling in the mill for better control of the hole location. I also used the step drill on the end plates for the flue. It's convenient that the pipe sizes available matched the step drill sizes so well. A little scraping with the deburring tool and it was good to go for silver soldering.

Sawn tube ends can be cleaned up and faced to exact length in the lathe, but be careful-- if a tool digs in and catches, it's instant scrap for that part.


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## shred (Dec 3, 2008)

Btw, some good Cracker building info and pictures here: http://www.16mm.org.uk/mom2008-10.htm


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## J. Tranter (Dec 4, 2008)

Thanks for your write up. I joined that group after you mentioned it when you started to show the boiler.

On the end plates did you just hammer them in to shape or did yo use a press with a form.
thank you again
John T


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## J. Tranter (Dec 4, 2008)

Never mind I read your post better ;D


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## shred (Dec 4, 2008)

Yeah, I considered pressing them for as long as it took for me to realize I had no suitable pressing device ;D


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## J. Tranter (Dec 5, 2008)

One more question for now(there be a lot more later ;D) Where did you get your pipe for the flue?


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## shred (Dec 6, 2008)

The flue pipe is ordinary 1/2" copper pipe. I had some hanging around already, although it's available in short lengths at the hardware store or better, piping specialists where I had to go for 1-1/4" by the foot anyway. Ordinary plumbing pipe reportedly isn't so good in larger size boilers, but at these sizes and pressures, it works ok. The heavier wall varieties especially.

I also made the boiler mounts. The plans show some sort of wooden material. Originally I hacked some mounts out of wood with a hole saw for mocking up purposes, but I decided to upscale for real and made them from some brass rod. This will be a lot worse for heat-transfer, but efficiency isn't at the top of the list for this engine. 

Take some 7/8" rod, clean it up a little in the lathe and drill for a convenient tapping size if desired. Move it over to the mill and setup a boring head to cut the desired diameter. Bore down, move over. Repeat until the 'half-hole' is the full width of the rod. If it doesn't fit perfectly, tweak the boring head until it does. Back to the lathe, part off and done. Notice that the picture shows a tactical error with the boring head setup-- from that side all the chips spray straight at you. It's what I get for being lazy and not wanting to move and re-tram the vice.  

[Edit: thinking about it some more, it might be worthwhile to bore out the rod to just over the curve depth while it's in the lathe, leaving only a small rim to curve. Heat transfer would be reduced with less surface area in contact with the boiler and the air pocket could be packed with insulation if really desired.]


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## J. Tranter (Dec 6, 2008)

Thank you again. I don't have a problem finding plumbing pipe. I'm a plumber by trade so I have all that stuff lying around.
Thank you again.
John


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## shred (Dec 8, 2008)

Spent most of the morning dinking with the gear train. Turns out when I redrew the plans for the gears I had available, I didn't leave quite enough play in the train and it would jam up periodically. Once I figured that out, I was about to make new side beams when I decided to try an offset bushing on the center gear to see what that did. I had to make 3 sets of bushings, but two thicknesses of Dr Pepper can (0.008" or so) on one jaw in the 3-jaw was just about right. You can't even tell by looking at it that it's offset, but just that much clearance did the trick.


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## shred (Dec 8, 2008)

After a morning of nothing visible to show for it without a pair of calipers, I started on the bodywork. It's just sitting on there for now, but at least it's something new to look at 

Here's a teaser with my LegoTM guy working out where to put the plumbing.


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## J. Tranter (Dec 8, 2008)

That is looking great. Thank you for showing.
John T.


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## shred (Dec 9, 2008)

Got most of the bodywork anchored. The roof is still loose until I sort out the burner and gas tank. The plumbing is mostly complete. There's still a lot to do before I can steam it, but here's the Loco getting ready for a test run on air.


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## Macca (Dec 9, 2008)

It's looking great Shred. I like the shot with the lego man, it gives a sense of scale.
Do you plan to use the cylindrical gas tank from the plans or a hidden rectangular one like tony bird did?
Are you modeling your body work after a particular engine, or is it your design? I think the roof gives it a cleaner look than having the top open.


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## shred (Dec 9, 2008)

Macca  said:
			
		

> It's looking great Shred. I like the shot with the lego man, it gives a sense of scale.
> Do you plan to use the cylindrical gas tank from the plans or a hidden rectangular one like tony bird did?
> Are you modeling your body work after a particular engine, or is it your design? I think the roof gives it a cleaner look than having the top open.


Thanks. It's a little big for Lego-scale. I suspect it'll be a little warm in for him in the cab under steam too. I'm not sure about the gas tank yet. There's not a lot of room left anywhere, but it won't run long on one fill of water. Some ideas I've had include the front footplates and under the cab roof as well as the usual spots.

The bodywork is entirely freelance-- I'm aiming for an 'American' look like the original Byers, but more enclosed and with a healthy dose of wacky/fun/toy look thrown in. The kind of thing I imagine running circles around the bottom of an X-Mas tree.


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## shred (Dec 10, 2008)

Got the safety valve built tonight before it started snowing (that's a rare enough event I had to grab the camera and go document it). 

The original plans have no safety valve and rely on the wobbler spring opening up and dumping excess pressure. I wanted to put in a real safety, so I stacked the filler and steam dome and made a safety for the front boiler bush.

I ended up using the safety from the Idris plans, except I modified almost all the dimensions . It works very nicely on air, popping off and on with great regularity and should provide plenty of flow for this size boiler. I considered making it in the form of a whistle for a few minutes since it does resemble one, but sanity prevailed. :

The only tasks remaining are to build the burner and gas system and fix the roof (plus a whole lot of finishing work). It's looking like a loco now!


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## Powder keg (Dec 10, 2008)

That is looking really great Shred!!!


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## Maryak (Dec 10, 2008)

Shred,

This is amazing. 
	

	
	
		
		

		
		
	


	




I admire how you work at such a small scale. :bow:

Best Regards
Bob


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## J. Tranter (Dec 10, 2008)

That is really beautiful. Did you by any chance take pictures of the build on the safety valve?
That looks like a good idea.
John T.


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## shred (Dec 10, 2008)

I don't have many photos on the safety valve construction, but here's one of silver-soldering up the valve stem and the Idris plans page with my scribbles on it from changing things around.

It all started because I didn't have a 1/8" stainless steel ball; the nearest size on hand was 5/32" and thus the changes cascaded. I made the retaining plug and top to be 1/4-28 threaded and 3/8" OD vs 1/4", the spindle was made from 3/32" brass rod with a .20" cup on the end (made from running a center drill lightly into some 1/4" stock, drilling to 3/32" and turning down to .200-ish, cut off and carefully silver solder on). The base was threaded to match the boiler bushes and made from 1/2" brass because those are 3/8" threaded. Instead of longitudinal slots and recessing the retaining plug, I made it solid and slotted the top for a screwdriver ('security' screwdriver bits work well for this). Since I then needed another steam escape path, I drilled six 1/16" holes around the top, using my 5C hex collet block to index them.

[Edit: if you see the safety-test video below, you might want to reconsider side-vents. That effect would be pretty cool vertically]


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## Paolo (Dec 11, 2008)

If you like I'll send you a drawing of one I have used on a my past project and I'm using for the next..
Cheers
Paolo


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## shred (Dec 11, 2008)

Paolo  said:
			
		

> If you like I'll send you a drawing of one I have used on a my past project and I'm using for the next..
> Cheers
> Paolo


Yeah, that would be cool. The more the merrier.

Here's a 20 second video of a live steam test of the safety valve. Now I know why the loco people aim the vents upwards. 

http://www.homemodelenginemachinist.com/index.php?action=dlattach;topic=2049.0;attach=1603 

View attachment SLSafetyValveTest.wmv


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## shred (Dec 14, 2008)

After much gnashing of teeth and pulling of my little remaining hair, I finally got the loco engine running on steam from the boiler. It wasn't nearly as easy as I'd thought, given as how it ran pretty well on air already, but the tiny boiler requires closer tolerance work than an air hose, so I wrote up a few commandments for those that might follow.


*Thou Shalt Have No Leaks* - even the smallest leak causeth woe and loss of pressure
*Thy Wobbler Faces Must Fit and Be Flat* - if thou canst see light between them, thou must continue lapping
*Thy Wobbler must run well on 5 PSI Air*- mayhap thus 15 PSI steam willst then function
*Thou Shouldst Rig a Pressure Gauge* - else the mysteries of non-function will abound and multiply

 :big:


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## Metal Mickey (Dec 14, 2008)

Well Shred that valve works fine. Most impressive. :bow:


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## shred (Dec 14, 2008)

Here's the Slightly Loco running on live steam. Without a burner and gas tank built, I'm using a creme brulee torch somebody gave us years ago that got seconded to general shop duty and silver-soldering of small parts. 

In the video the engine is running on about 10 PSI steam. That's all this torch can get out of the boiler with the engine going. Hopefully a real burner will improve that.

[youtube=425,350]7EkiiEZTk2A[/youtube]

[ame]http://www.youtube.com/watch?v=7EkiiEZTk2A[/ame]


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## Macca (Dec 16, 2008)

Looks good Shred, I can't wait to see it move itself along.
I started playing with some bits for mine tonight, I grabbed some 1/2" pipe for the flue, but it looks too small to me. It has an internal diameter of just over 10mm (about 0.4" ???). In your pictures the flue looks larger than that, do you know what the I.D. is?
I think maybe yours is 1/2" I.D. whereas mine is 1/2" O.D.


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## shred (Dec 16, 2008)

Macca  said:
			
		

> Looks good Shred, I can't wait to see it move itself along.
> I started playing with some bits for mine tonight, I grabbed some 1/2" pipe for the flue, but it looks too small to me. It has an internal diameter of just over 10mm (about 0.4" ???). In your pictures the flue looks larger than that, do you know what the I.D. is?
> I think maybe yours is 1/2" I.D. whereas mine is 1/2" O.D.


The ID on mine is a little over 1/2". It's sold as '1/2"' pipe, but the OD is closer to 5/8" (add 1/8"th to the sold-as size of copper pipe to get the real OD). You're probably looking at a piece of "3/8" pipe, which has an OD around 0.5". 

The ID can vary by what thickness the walls are-- K,L or M. I think my flue is the L type.

http://www.sizes.com/materls/pipeCopper.htm has a handy chart. 
http://Copper.org has a ton of info, but their site loads very slowly for me.


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## J. Tranter (Dec 17, 2008)

What gears are you using? I'm having problems finding some.
Thank you
John T.


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## Macca (Dec 18, 2008)

O.K. I think I have this copper pipe sorted out.
The Australian standard (1432:2000 for those keeping score at home) is some weird half-breed of metric and imperial. For example DN15 pipe (commonly sold as 15mm) has an outer diameter of 12.7mm (which is apparently equivalent to 1/2" pipe). DN80 has an outer diameter of 76.2mm (which is 3"). They have converted imperial pipe sizes directly to metric, and then rounded the result to get the new metric pipe size. There seems to be no rhyme or reason to the rounding off, some go up and some go down.
What I need is DN18, which has an O.D. of 15.9 mm, Unfortunately the hardware stores here only seem to stock DN15(1/2") and DN20(3/4"). I will try to get to a plumbing shop on the way home from work tommorrow, and see if they have any in stock. I hope I don't have to buy a 6m length though.


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## jack404 (Dec 18, 2008)

Australian standards.. bloody nightmare..

good luck


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## shred (Dec 18, 2008)

J. Tranter  said:
			
		

> What gears are you using? I'm having problems finding some.
> Thank you
> John T.


I used metal R/C car gears from a hobby store that caters to the high-end gas & electric parking-lot racer crowd. I just looked for the combination of smallest gear and biggest gear I could get within the same DP.

[Update: I found a packet from one of them-- they're from Robinson Racing and a 48P pitch- http://www.robinsonracing.com/catalog/48pitchpinion.html]


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## shred (Dec 18, 2008)

Macca  said:
			
		

> O.K. I think I have this copper pipe sorted out.
> The Australian standard (1432:2000 for those keeping score at home) is some weird half-breed of metric and imperial. For example DN15 pipe (commonly sold as 15mm) has an outer diameter of 12.7mm (which is apparently equivalent to 1/2" pipe). DN80 has an outer diameter of 76.2mm (which is 3"). They have converted imperial pipe sizes directly to metric, and then rounded the result to get the new metric pipe size. There seems to be no rhyme or reason to the rounding off, some go up and some go down.
> What I need is DN18, which has an O.D. of 15.9 mm, Unfortunately the hardware stores here only seem to stock DN15(1/2") and DN20(3/4"). I will try to get to a plumbing shop on the way home from work tommorrow, and see if they have any in stock. I hope I don't have to buy a 6m length though.


As long as you can get a burner down the pipe, a smaller flue will allow for more water in the boiler. IIRC the original plans had a 15mm OD flue, but as long as the holes in the ends match up, there's not much need to stick exactly to spec. One thing to look for is what's called a 'repair coupling'-- those are sized to telescope over the next-size down pipe and are available in short lengths at even the so-called hardware stores here, so one sized for DN15 might be just the ticket.

If all else fails, try a plumbing supply store. They don't much like DIY types in many of them but if you say you're making some toys and that's what the plan calls for, they'll probably be happy.


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## shred (Dec 19, 2008)

Got the Goodall valve done. Strictly speaking, it's a 'Goodall-type' quick-fill water valve since Mr. Goodall didn't make it, but as info is a tad difficult to dig up on them unless you are in-the-know, I'm going to leave it there like that for the search engines to pick up.

Here it is with the Crap-o-Cadtm drawing. Note to self: Make more use of the color upgrade 





Anyway, the key to these clever things is the little silicone rubber sleeve; the black part on the thin end at left in the picture. It covers a port hole (actually two) which connect to a blind hole coming from the big end (the 'top' of the valve once installed). The idea is once this is screwed into the boiler, you stick a source of pressurized water in the hole at the top (I'm using a 25ml syringe, so I drilled the top to fit that; traditionally, converted garden spray bottles are used) and the incoming water under pressure squeezes out past the rubber sleeve, refilling the boiler. The pesky steam and associated stuff you want to keep in the boiler stays there because as soon as you release pressure the rubber pulls back down over the holes and seals them. 

This one is somewhat smaller than most-- most use the 1/4" silicone tubing, but that wouldn't fit in the steam banjo. I spent a while looking for thinner silicone tube, checked the hobby shops, fishing stores and eventually found it masquerading in the archery supplies as peep-sight parts.

The way I machined it was to chuck some 1/2" brass bar in the lathe and turn 0.5" down to the 5/16" thread major pitch, then turn the end down to 0.2" dia for a length of 0.3", switch to a parting tool and cut the o-ring groove and make the .125" dia neck. Then I threaded with a die, un-chucked and carried the bar over to the mill to drill the #55 cross-hole. (Much easier to hang onto for drilling before parting off). Part off back on the lathe. I had a little length of 1" bar already drilled and tapped to match, so I put that in the lathe, screwed the partially-done valve in and finished the top, drilled the 5/32" filler hole and then the 1/16" blind hole with some careful peck drilling. Unscrew, wrestle some tubing over the end, trim with an X-acto knife, pop on an O-ring and it's done.


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## shred (Dec 21, 2008)

Got a couple more things built this weekend; 

First, after a trip by a train-specializing hobby store I got the idea to make some wheel rollers. The idea being you can put a set under each driving axle of a locomotive and it can run in place. Handy for debugging and steaming up and so on. They're a pretty simple design-- bolt some skate bearings to the sides of 1.25" thick blocks. I slotted mine down the center so they'll clear the third-rail common to almost all O-gauge track (the bearings do not touch the track even though it looks like it in the picture)






The slot is 1/4" wide, so they'll also clamp onto a piece of 1/4" stock for non-track usage.






You'll notice that one of mine only has 1 set of bearings. Those of you playing along at home will realize the wheel spacing on the Slightly Loco isn't enough to run two pairs of skate bearings between them. I had thought I could just run one on the front wheel set and the back two would keep it in place, but unfortunately the vibration set up by the wobbler is enough to render them not very useful. Ah well, I can use them if I do a longer wheelbase O-gauge loco and they make cool indestructible toy cars for the kids


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## shred (Dec 21, 2008)

The other thing I got done this weekend was the butane gas tank and valve, which are assembled into one unit. The tank is a pressure vessel like the boiler, so the same cautions and testing should take place with it too. I'm planning to mount it on the left side with the gas valve control coming in from the left side window as long as the burner cooperates. The Ronson-type filler valve will be accessed via lifting off the roof.






You can also see the Goodall-style filler valve is installed, and the very sharp-eyed will notice a new hole in the smokebox support that was added to act as a condensate drain and provide some fresh air flow to the smokebox (reportedly small-scale gas burners prefer that, but I don't know why)


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## J. Tranter (Dec 22, 2008)

Can you give more info and pics of your butane tank? I'm getting all my parts together so I can have a go at making this engine so I can use all the help I can get.
Thank you 
John T.


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## shred (Dec 22, 2008)

The butane tank is mostly to the plans, except for using the closest-size-imperial copper pipe (I forgot which but it's very close-- 3/4" maybe?), imperial tooling for the valve body hole (1/4" so I could use an end mill to drill the offset hole) and innards (#4-40 threaded needle & #10-32 o-ring seat threads, #59 outlet, 1/16" inlet) and I put in a bushing for the Ronson valve (swiped from a $1.79 Harbor Freight Pencil Torch; needs fine-thread metric tap) in the top instead of cutting it all from one piece of solid. That let me fix the un-drilled bushing in the hole for a quick pressure leak-test. I'm not sure I like the end-cap construction with silver-solder however-- it seems easy to make a poor joint. The way I did it (setting a ring of 1/32" SS between the parts & heating) left quite a gap that had to be filled. Were I to do it again, I'd think hard about flanged copper ends or using pipe caps.

In Tony's writeup, he talks about using the burner from a pencil torch as a burner. That would work, but the way the cheap HF torches are made, the orifice is only a tiny punched piece of foil trapped in the burner head which clogs easily and can't be un-stuck. The Ronson-style gas filler valve does seem to be adequate quality and easily removable with a 'security' screwdriver bit set. 

For the jet, I plan to use some camp-stove spare-parts. Jetboil has a maintenance kit with a jet that I think is .021mm in a kit with some O-rings and piezo sparker for $10 (that jet also uses an odd metric thread). Other stove spare-parts that might be usable include MSR-- their 'Kerosene' jet orifice is listed as 'smaller than #80', but I've not found any actual measurements (it seems to be threaded 1/16"-NPT). I also found an article including info on swaging larger (as-in #70-ish) holes down to jet sizes, but had already obtained the Jetboil parts, so I've not tried it.

Also, if you haven't started cutting yet, Tony has built some newer versions with slightly lengthened frames (~10mm) and the gas tank moved to under the rear frame rails. That's a neat tidy solution I would have gone with if I'd thought of it, Ford Pinto flashbacks notwithstanding


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## shred (Dec 24, 2008)

The burner is made. That completes the Loco parts! 

*[Note: I neglected to insert this here earlier, so I'm sneaking back in to do it for the sake of continuity]*

The burner is very different from the plans. Reportedly the one in the plans doesn't work that well and the authors switched to a 'poker' style burner. I got some details from Tony directly and modified them in the usual Slightly Loco style. 






Here's the Crap-o-CADTM drawing with what passes for the key measurements (drawn, as usual, after the part is made-- notice it doesn't actually match the picture; I discovered that making the last two slots the same depth as the others made the burner much easier to light and keep lit.)



(click the image for a larger version)

The jet is from the JetBoil camping stove spare parts kit. The thread was so oddball metric that instead of waiting for a tap, I drilled a close-fitting hole and loctited it in place [edit: this isn't a very good idea.. silver-soldering it to a threaded sleeve would be better]. If you make the brass parts push-fits, it makes tuning and tweaking easier, even wholesale replacement of the burner if you want to try more slots or different configurations. You can anchor them in place later with some high-temp glue or solder.
_*
[end of insert]

[double-extra insert]*
With a loupe, I did my best to estimate the size of the JetBoil jet orifice. Near as I can tell, it's about .008" or about... .21mm.. I wonder if that's why it has "21" stamped on it

Also note later on I made a right-angle input jet-holder to make the plumbing neater.
*[end 2X Insert]
*_

All it needs now is some tuning and a lot of polishing and detailing.  That won't happen for another week or more as I'm off to see the family... if I can ever get out of the Phoenix airport... been stuck here for 6 hours already and another 2 to go 

Anyway...


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## shred (Jan 3, 2009)

It moves! I got the burner tweaked and running with the JetBoil jet (the burner works very poorly outside the boiler flue, but well enough inside) and the butane tank valve mostly sealed up, so here's video of the very first run at my extensive R&D Test Facility (ok, it's a loop of snap-track on the garage floor ):



​
;D ;D ;D

Lighting the burner is fun. Turn on the gas and hold a lighter over the smokestack. A tall blue flame shoots out of it for a bit, then sucks back into the boiler. 

Next items are to attach the roof, shorten the gas valve handle and improve the gas tank mounting. And go buy more gas. I ran out playing with it


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## ksouers (Jan 3, 2009)

That's awesome, Shred!

Congratulations! It looks and runs great! :bow:

Love that high-falutin', super secret test facility. Where is it? Area 56 1/2?  ;D


Kevin


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## Maryak (Jan 3, 2009)

Oh what a wonderous machine 
	

	
	
		
		

		
		
	


	









Best Regards
Bob


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## joe d (Jan 3, 2009)

Shred

That's super! sounds good too. (I've got some of that test track in my secret storage facility behind the furnace....)

Cheers, Joe


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## stevehuckss396 (Jan 4, 2009)

Just saw the video. SWEET!!


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## shred (Jan 4, 2009)

Thanks all. I'm getting dizzy watching this run in circles, it's so much fun. 

 For those having trouble viewing it, there's a murkier version of the video on YouTube now

[youtube=425,350]3hcLNzA0x2E[/youtube]
[ame=http://www.youtube.com/watch?v=3hcLNzA0x2E]http://www.youtube.com/watch?v=3hcLNzA0x2E[/ame]

And I sneaked back in to my pre-Xmas post and put up some details on the burner.


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## J. Tranter (Jan 4, 2009)

That looks and runs great. Thanks for posting this. I am still working on mine I can only hope it turns out as good as yours.
J. Tranter


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## shred (Jan 9, 2009)

I've been doing way too much playing with the loco instead of finishing it, but having fun is what this is all about 

I did get some time to clean up the gas and burner plumbing-- I built a right-angle jet holder, installed a pipe cap as a basket to hold the gas tank and shortened the valve up so it only barely sticks out the window (it can be easily rotated to out the back, front or side as needed). Now the big loop of silicone tubing out the back is gone, replaced by a small loop under the cab roof (I like having it as a thermal barrier-- the jet parts can get very hot, which does bad things to the butane valve delivery, so a snippet of tube stops any heat conduction through the pipework)





I also installed the steam dome cover-- I'll post more on it later since cutting the saddle curve took some creativity, and there's a funky bayonet-mount for the steam pipe but here's an overall picture for now (you can see how dirty it is from playing with it )


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## shred (Jan 12, 2009)

I've been running this far more than building on it, but I did get around to doing a little 'bling' work-- making a saddle and a top for the smokestack as well as re-plumbing the exhaust with 1/8" copper instead of 3/32"-- back pressure was hindering performance a little. At the moment, the record is 50+ laps of the extensive test track facilities, or about 500 feet on one tank of water.

The other thing is I bead-blasted some parts and put mounting rails on the roof. That was a little tricky since it's all curved and I had no measurements, so what I did to locate them was to set the rails on the sides of the cab, dab a little superglue on the tops and stick the roof on. That won't hold up long-term, so I then took the roof off and clamped the now-superglued rail to the roof so it wouldn't fall off during soldering and soft-soldered it on. 

Here's the 'before' picture. Note the flux and short bit of soft solder lying on it. The whole setup is in a vice to let gravity help with the solder flow.




Apply heat with the Creme Brulee torch to the other side (it's actually burning, though you can't see the flame in the picture)




and moments later... the rail is soldered on. It's not the prettiest joint since there's leftover superglue goo around, but as this is up under the inside of the roof, you can either leave it like that, or soak the roof in acetone to dissolve the old superglue, then clamp and solder again, but this time being neater since everything will be clean. As yet, I've taken the former path 

The cool thing with soft soldering is if you're careful with the heat, you won't even discolor the parts. I did no cleanup to the roof since soldering and these pictures (and even the 'soldering' picture above is of the second rail, the other edge having already been done). Had I wanted to, I probably could have tinned the rails and just soft-soldered them on right there and skipped all the supergluing.


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## J. Tranter (Jan 12, 2009)

Shred a couple of questions if you remember. What size holes did you drill for the bushings and what thread did you use for them? The plans call for an 8 and 10mm thread I believe and I'm wondering if I should go and buy metric taps or if I can use what I have.
Thank you for any help you can give.
J. Tranter


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## shred (Jan 12, 2009)

J. Tranter  said:
			
		

> Shred a couple of questions if you remember. What size holes did you drill for the bushings and what thread did you use for them? The plans call for an 8 and 10mm thread I believe and I'm wondering if I should go and buy metric taps or if I can use what I have.
> Thank you for any help you can give.
> J. Tranter


I used "what I had", which no doubt would horrify any Proper Model Engineers . IIRC that was a fine-thread 5/16" and maybe 3/8", but I think they're both 5/16" UNF (-24?). As long as you plan to make the mating parts yourself (safety/filler/steam/gauge/plugs/etc-- model boiler fittings are only made in a few thread styles), and have enough threads for strength it should be ok. At a guess the holes were 1/2"-- some convenient size on the step drill anyway. I used 3/4" bronze to make the bushings, but turned it down to 9/16" or so for the flange. 

If you haven't soldered up the boiler flanges yet, I'd consider moving the front one to right behind the smokestack hole and making the rear one a little bit of an 'outie'; that picks up a little more water volume, which is good in a tiny boiler like this.

At the end I did buy one metric tap for the Ronson-style gas filler valve I recycled from an old pencil torch-- IIRC it was a slightly odd fine metric thread, but one Enco had. 3.5mm*0.5 or something-- I can look that up if needed. Officially the gas jet was also threaded some oddball metric size, but I loctited it in place since it's not part of a pressure vessel [edit: see SandyC's comments below re; Loctite]


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## J. Tranter (Jan 13, 2009)

Thanks for the reply. Will aluminum bronze be ok for the bushings? And what gas jet did you wind up using? Thank you for all your help.
J. Tranter


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## shred (Jan 13, 2009)

J. Tranter  said:
			
		

> Thanks for the reply. Will aluminum bronze be ok for the bushings? And what gas jet did you wind up using? Thank you for all your help.
> J. Tranter


Al-bronze for the bushings I don't know about. I was all set to use some brass I had, remembering my old Mamod, but after reading about de-zincification, and not wanting to risk it I went out and got a foot (well, 13".. I have no idea why bronze is sold in 13" lengths) of regular bronze for the job. Enco puts it on sale a lot. You might want to ask the boiler specialists about Al-Bronze (if any are reading this, chime in!). 

The jet I'm using is the JetBoil backpacking stove jet. They sell a spare parts kit of the jet, a spare piezo igniter and sometimes some o-rings for ~$10 at backpacking and camping stores. I checked it out under a loupe the other day and it appears to be a .008" / .21mm orifice which is pretty close to the recommended sizes. That makes sense since it's designed to run a little gas burner not very different from the engine burner (that's pretty much how I picked it-- I was impatient over the holidays and didn't want to order in a model jet, so I went to REI and looked for the smallest butane/propane stove they had and asked about spare jets for it.)


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## Maryak (Jan 13, 2009)

In the OZ model boiler code for copper, bushes in direct contact with the boiler shell are Phosphor Bronze. Aluminium Bronze is not listed in the code.

Hope this helps. ??? ???

Best Regards
Bob


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## SandyC (Jan 13, 2009)

Hi Shred,

It looks like you are having a great deal of fun with that loco and what a great job you are making of it.

You mentioned that your gas jet had a weird 'metric' sort of thread..... well, the majority of the small gas jets used by manufacturers of camping gas cookers, DIY blowlamps and model steam loco's ('G' gauge etc) have a 1BA thread..... which is based on a metric form..... 5.3mm OD &#160;x &#160;0.899mm pitch &#160;(0.2087" dia x 0.0354" pitch (28.25 TPI))

The gas jets I use (as do the majority of UK/EU manufacturers and at least 1 American company) were originally manufactured by 'Calorgas' who eventually sold their camping gas division to 'TAYMAR'...... who were then bought out (taken over) by 'COLEMAN'.... an American company.
It is, therefore, possible that JetBoil get their gas jets from 'Coleman', with their own 'CUSTOM' markings on them...... if so then they would most likely be 1BA thread.

These gas jets are available (mail order) from the following (amongst others): -

www.roundhouse-eng.com

www.polymodelengineering.co.uk &#160; &#160;Then look under the 'BRUCE ENGINEERING' section.

sizes commonly available are: -

Number 3 which has a 0.15mm dia jet bore

Number 5 which has a 0.2mm dia jet bore

Number 8 which has a 0.25mm dia jet bore

Number 12 which has a 0.3mm dia jet bore

Number 16 which has a 0.35mm dia jet bore

All have 1BA thread.

The NUMBER system shown is still used in the UK/EU since this ties in with the original 'Calorgas' numbering system.
and you Know how us Brits just hate to change things..... &#160;:big: :big: :big:

I hope this is of some help to you. &#160;;D ;D 

As for your question "why do they sell Bronze in 13" lengths?"... I suppose it is that they may purchase in 1 metre lengths (39" + a bit for cutting), and cut it into 3 pieces for resale... just a thought.  

Here in the UK you can buy it in whatever length you want up to around 4 metres..... you need DEEP POCKETS though.... :'( :'( :big: :big:

J.Tranter.....

I would not recommend ALI-Bronze for bushes.... it is difficult to Silver Solder...... it can be done, providing the Ali content is not too high, however, it does requires special flux additives (required to clear away the inevitable ALI-OXIDE) to be certain of good joints.

A much better choice would be either SAE 660 Bronze, Colphos 90 or Gunmetal (LG4).... all of which are both easy to machine and take Silver Solder very well.

Straight PB102 Phosphor Bronze is also suitable, however, it is much more sticky to turn and thread.

I use SAE 660 for all of my bushes.

Best regards.

SandyC. &#160;;D ;D

BTW Shred..... Might I suggest that you keep a &#160;very very close eye on the LOCTITE joint you used for the GAS jet on your burner...... Loctite is not very good at high temperatures, and if the jet comes loose it can easily be forced out by the gas (typically 25psi pressure @ room temperature, but much higher depending on temperature... can reach 6BAR (87psi @ 40deg C))....well.....you don't want to see the results..... much better to get the right tap and screw the jet in.   :'( :'(.... PLAY SAFE.


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## shred (Jan 13, 2009)

SandyC  said:
			
		

> Hi Shred,
> 
> It looks like you are having a great deal of fun with that loco and what a great job you are making of it.
> 
> ...


Thanks for the expert advice Sandy-- I confess to not being very happy about loctiting the jet in, though I did use #620 hi-temp Loctite and have limited the gas valve itself so even flat out it would only make a medium-size flamethrower  Unfortunately (well, not that unfortunately, I have even less access to BA taps) it didn't seem to match a BA thread either-- it was somewhere between 3.5 and 4mm x 0.5mm thread, though I've forgotten the exact details. What I'll do is silver-solder the current jet into another threaded piece that has a thread I do know so I can still fish it out for cleaning, but not worry about it coming loose. 

Looks like it's about #5 size by your chart. Elsewhere somebody said they believed the jet-number was the diameter in thousandths of an inch, which would put it at #8 size and that sounded a little big.


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## shred (Jan 13, 2009)

Following up to my own post, it was less than an hour's work to turn up a threaded sleeve, silver solder the gas jet in, tap the burner and reassemble it all properly. Thanks for the additional kick in the pants SandyC.

And I had a thought to address this particular thread, my expectations for it and tie it to the rudeness one just in case people are wondering (btw, I've got no complaints so far)--


I expect any and all to jump in if they see safety problems. 
I invite interested parties to comment and contribute as desired, especially if they see something that might be missed by a relative novice such as myself or the others playing along ("When are you planning to martinize the whiffer bearings? ... I found it easier to do that before pinking the rasterfratz", to make up an example).
Should you want to post about your fully functional live-steam, rivet-correct 2-10-10-2 Big Boy in N-scale, you are kindly and politely invited to shove off and start your own thread (seriously, I'd love to see it, but not here)  ;D

Thanks


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## rleete (Jan 13, 2009)

"When are you planning to martinize the whiffer bearings? ... I found it easier to do that before pinking the rasterfratz"

 ;D  I found this particularly funny. Just struck the right note.

Personally, I have little interest in locomotives, my main focus being stationary engines. But, I do enjoy reading all the related projects. I have been following this thread because of the detailed build and accompanying pictures. If you were building something completely different, I'd still read it all because of the nice pictures and 'how I did it' comments. That is worth the time in itself.


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## J. Tranter (Jan 13, 2009)

Seriously thank you for all your help Shred. I greatly appreciate it.
Thank you also Sandy C. and Maryak for the answer on the bronze.
J. Tranter


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## artrans (Jan 14, 2009)

thats cool as hell but the nicest one I ever saw was relax just kidding sorry again the the past post that really is cool why don't we see any steam vapors what scale track is that ho g o very nice.where are the palns for that or is it your design.


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## Brian Rupnow (Jan 14, 2009)

Shred, I think you have done a marvelous job, and a great job of documenting it. I enjoyed the video.---Brian


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## SandyC (Jan 14, 2009)

;D ;D



> it was less than an hour's work to turn up a threaded sleeve, silver solder the gas jet in, tap the burner and reassemble it all properly.



Shred,

An excellent and correctly engineered solution to a tricky problem. :bow: :bow: :bow:

I hope the kick didn't hurt too much. ;D ;D ;D..... I have seen to many accidents with leaking LPG gas.

From your latest description, it would, indeed, seem that JetBoil are producing their own gas jets.... and what a weird thread!

Keep happy.

Best Regards.

SandyC. ;D


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## shred (Jan 14, 2009)

artrans  said:
			
		

> thats cool as hell but the nicest one I ever saw was relax just kidding sorry again the the past post that really is cool why don't we see any steam vapors what scale track is that ho g o very nice.where are the palns for that or is it your design.


It's O-gauge track, but it's 'narrow gauge' for the scale, if the term 'scale' still applies  In theory it can run on the next size up track (Gauge 1) by moving the wheels outboard of the frame rails, but mine doesn't actually fit G1 track since the frame rails are a little too thick (I have resisted making the axles even longer to make a slammed 'hoopty' locomotive for wider-gauge track :big

The reason there's no visible steam is the steam exhaust is piped into the smoke-box chamber at the front of the boiler. The gas-burner ends there and the burner exhaust is so hot and so much more volume that it makes the steam disappear. If I pull out the exhaust pipe so it exhausts to the air, then you get some visible steam, but it comes from the exhaust pipe, not the smokestack. Since I like steam clouds, I tried putting a tube inside the smoke-box to route the exhaust steam straight to the top of the smokestack, but it's still not visible enough.


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## J. Tranter (Jan 21, 2009)

Shred what size did you cut the 3/8 tube on your burner?
John Tranter


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## shred (Jan 21, 2009)

J. Tranter  said:
			
		

> Shred what size did you cut the 3/8 tube on your burner?
> John Tranter


Hmm.. I don't remember. I can check later. It's not terribly critical-- there's about half an inch sticking into the flue, and the air hole is just behind the plug, so I suspect I put the center of the air hole 1" from the end. The rest of it holds the jet in place and you may want to shorten that or make it right-angle to clean up the plumbing. The flue end has the slotted tube telescoped into it, so as long as it grips that tube well and puts the first slot around 0.75" from the plug, it should be ok. The idea is that the slotted tube can be moved and rotated for tuning or replaced to try different slot configurations.

Also I ended up silver-soldering the end cap on the slotted tube-- the 'press' fit I made wasn't tight enough so it didn't like to stay put.


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## stevehuckss396 (Jan 21, 2009)

Now that the little loco is running, any plans for paint and polish? Maybe a few dressup trinkets?

Steve


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## shred (Jan 22, 2009)

stevehuckss396  said:
			
		

> Now that the little loco is running, any plans for paint and polish? Maybe a few dressup trinkets?
> 
> Steve


Yeah.. I've been meaning to do more, but been a little distracted lately. I did throw together a 'woodburning' stack cap to see how it looked. Not sure if I prefer that to the small cap. I like both, but in different ways. I also soldered a real number to the smokebox door and did a little more cleanup.

Plans are to do some rivet lines on the cab, then paint as much as I can stand. I'm thinking black with a silver smokebox at the moment, but the stores seem to be out of silver hi-temp BBQ paint (they have black, white and .. almond in stock ???)


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## Macca (Feb 1, 2009)

Your loco looks great Shred, I hope mine turns out that nice.
I haven't had much time to to play around in the shed lately, I picked up some 5/8th" pipe for the flue during the holidays and its just been sitting round gathering dust. 
I finally got down to the shed yesterday, and planned to solder up the boiler (most of it anyway). I had a bit of trouble drilling the flue holes in the boiler end plates, I found them very difficult to hold. It would probably be better to drill the holes before forming the plates. Once I got both end plates drilled, I drilled the top of the boiler for the bushes and chimney, this went without incident. At first I tried to solder the boiler together one part at a time (dumb idea, I know). I got the first end plate soldered in and, because of my impatience, knocked it off the bench. Copper pipe that has just been silver soldered (and is still hot) is quite soft, and will deform if you look at it funny, let alone drop it onto concrete. So I desoldered the end plate, cut and drilled a new boiler tube, and cleaned and assembeled everything ready for silver soldering. This time it worked like a charm, here it is after being pickled overnight.




The chimney is just sitting there, so I could see how it looked.
I drilled a section of pipe to make the smokebox, and split it down one side. It was then annealed and spread apart slightly to fit over the boiler.




There is about 1mm between the front of the smokebox and the front of the boiler. I plan to cut and solder a small piece of copper to fill in the gap at the bottom.
Hopefully tomorrow I will be able to order some phosphor bronze to make the bushes, then once they are soldered in I will be able to pressure test the boiler.
Do any of the Aussies know where I can pick up a suitable pressure gauge for a decent price? www.ejwinter.com.au has them for $100 each, this seems incredibly expensive to me.


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## Maryak (Feb 1, 2009)

Macca,

Seems to be about the mark in Oz for 3/4" dial. I've found hobby mechanics in Qld pretty good to deal with.

Best Regards
Bob


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## stevehuckss396 (Feb 1, 2009)

shred  said:
			
		

> Yeah.. I've been meaning to do more, but been a little distracted lately.
> Plans are to do some rivet lines on the cab, then paint as much as I can stand. I'm thinking black with a silver smokebox at the moment, but the stores seem to be out of silver hi-temp BBQ paint (they have black, white and .. almond in stock ???)



Black sounds great. How about some fancy pinstripe.

I was thinking about a bell. Didn't most older steamers have a bell clanging as they left the station.

Just a suggestion, Even without it, it's still is a great project.

Steve


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## shred (Feb 1, 2009)

Macca  said:
			
		

> I finally got down to the shed yesterday, and planned to solder up the boiler (most of it anyway). I had a bit of trouble drilling the flue holes in the boiler end plates, I found them very difficult to hold. It would probably be better to drill the holes before forming the plates. Once I got both end plates drilled, I drilled the top of the boiler for the bushes and chimney, this went without incident. At first I tried to solder the boiler together one part at a time (dumb idea, I know). I got the first end plate soldered in and, because of my impatience, knocked it off the bench. Copper pipe that has just been silver soldered (and is still hot) is quite soft, and will deform if you look at it funny, let alone drop it onto concrete.
> ...
> 
> There is about 1mm between the front of the smokebox and the front of the boiler. I plan to cut and solder a small piece of copper to fill in the gap at the bottom.
> ...


Looks good. You may not even need to fill the gap at the bottom of the smokebox-- it might make a useful air vent and/or drain hole. I got my pressure gauges at some surplus place long ago, but I've seen them in the hardware store in with the plumbing and air bits-- you don't need an ME one unless you want to install it on the loco permanently. You'll want one that goes well above 100 PSI (or equivalent Bar)-- a friend suggests pressure testing the gas tank to higher pressures than the boiler-- some people test as high as 400 PSI in larger scales since they do goofy things like heat the gas tank to get the gas flowing better.

When you do get a gauge, put it on a loop or U of copper tube so you can use it for steam tests later on.

I silver-soldered my boiler one end at a time so I could check the joints on the inside as much as possible, but whatever works, works; you should be able to do a pretty good inspection from the bush holes with a flashlight. Keeping the boiler from being dinged is a non-stop process after you silver solder it in any case.

If it warms up enough today, the plan is to start with some paint on mine. I went by an auto parts place and got some high temp 'header' paint to try on the smokebox.


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## shred (Feb 2, 2009)

I started in on the painting today. I'm not all fired up about paintwork and still haven't totally decided how or what I want painted, so I'm being a little haphazard about it (that and there was some sort of game on today). Current thought is mostly black with a silver smokebox and brass accents. 

So, after total disassembly, putting the not-to-be-painted and maybe-paint-later parts in one box,



I sprayed a few parts with the first coat of black 'hi temp' BBQ paint (it looks much darker in person)



I plan to sand the bushing ends back to brass later on.

Since BBQ paint wasn't available in silver, only black, white and, almond ??? (hmmm... all the BBQ's around here are either black or... silver, go figure), I got some 'ultra high-temp' header paint at an auto parts place. This particular stuff has off-car curing instructions that I'm confident almost nobody ever follows-- 30 minutes at 250'F, 30 minute cool down, 30 minutes at 400'F, 30 minute cool down, 30 minutes at 600'F, cool down.

But, I happen to have a craigslist-special little kiln and multi-step temperature controller (note, these are handy things occasionally, so if someday a small programmable glass, ceramic, wax burnout or heat-treating kiln floats by cheap and you have the cash, grab it), so away we went. Here's the smokebox getting 'ready for a ride on the Reading'




And after it's 3 heating/cooling/soaking cycles, it came out pretty nice. The base is going to be painted black later on, and the blem near the top will be covered by the smokestack, so we'll go with it.


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## Maryak (Feb 2, 2009)

Shred,

Nice kiln, looks like the china painting kiln my ex (1st) wife has/had?

Best Regards
Bob


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## shred (Feb 2, 2009)

Maryak  said:
			
		

> Shred,
> 
> Nice kiln, looks like the china painting kiln my ex (1st) wife has/had?
> 
> ...


This one was used for lost wax mold burnouts, but I suspect the same kilns or slight variants get sold into lots of different markets-- glass fusers, heat treaters, casters, painters, ceramics, etc. It's about 10"x10"x10" inside and heats to 2000'F. This one has a separate controller though many are now integrated (originally I was trying to deal for just the kiln, but the seller ended up throwing in the controller-- an excellent accident for me, I didn't realize how useful it would be).


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## shred (Feb 8, 2009)




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## Macca (Feb 8, 2009)

Very nice. ;D 

Last week was pretty much a write off for me, I worked overtime every night, didn't get home till midnight on friday .
I made up the bushes on saturday, and got them soldered in. The phosphor bronze was a bugger to tap, it kept grabbing, I ruined one bushing from chuck slippage. I dilled both holes on the boiler 10mm, and tapped both bushes M8x1.0. Now I have to make up a pump and pressure test the boiler, so I can see just how bad my soldering was.

I have a few questions for you;
How did you end up attaching the wheels?
How is the boiler held down? I understand the front base is soldered on, and probably bolted from below, but what about the back of the boiler? Is it held down by the bodywork?
Can you show some more photos of the steam dome? Specifically the bayonet style bit, and I am a little confused about how the filler valve and banjo bolt fit together, can you do a crap-o-cad diagram?


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## shred (Feb 8, 2009)

Macca  said:
			
		

> I have a few questions for you;
> How did you end up attaching the wheels?
> How is the boiler held down? I understand the front base is soldered on, and probably bolted from below, but what about the back of the boiler? Is it held down by the bodywork?
> Can you show some more photos of the steam dome? Specifically the bayonet style bit, and I am a little confused about how the filler valve and banjo bolt fit together, can you do a crap-o-cad diagram?


Yeah, I like the look of bare brass and copper, so it was a leap to paint it all, but I'm pretty happy how it turned out. The black BBQ paint is pretty fragile though. I'll have to source a substitute next time.

The driving wheels are fixed by loctiting them to the gears. Those set-screw to the axle. The off-side wheels can freewheel if they like. They are kept separated by a length of brass tube slipped over the axle. You can see I've put some shaft collars on the outside ends of the axles-- those were going to go on the inside and attached to the off-side wheels to create a set-screw attach there too, but it had plenty of traction as-is, so I put them on the outside for looks.

The boiler is held down at the front by the smokebox and mount for that-- that's bolted in from the bottom. The aft end more or less floats-- the rear saddle is bolted to the frame, but the boiler just sits on it-- that allows the boiler to expand and contract as it heats and cools. The steam pipe and bodywork help anchor it as well. I had some rubber tube between the cab bodywork and boiler since I left a huge gap, but it's not there now and seems to be ok with just the steam pipe and smokebox holding it on. If I was going to make a new cab, I'd have it be a much closer fit.

Here's the steam dome C-o-C. Basically it's a banjo setup that's been drilled and tapped from the top to hold the Goodall-type valve. There are other ways to do it that might make for less vertical stack-up, but this one worked for me. Make sure there's clearance between the rubber bit on the Goodall and the inside of the fitting so water can get in. Note that I've drawn the fitting sticking below the bushing. You don't want that; it'll create excess water out the steam spout if the boiler is full. The unit removed from the boiler is visible front-and-center in the 'parts-not-to-be-painted' picture above and I've included a blowup below.


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## Macca (Feb 9, 2009)

Thanks Shred, you confirmed my suspicions.
I assumed the filler valve would have to extend below the steam outlet, which is where my thinking got stuck. I don't suppose it matters too much if the water inlet is above the steam outlet. Is there a risk of forcing water out of the boiler and into the engine when filling? And does it matter all that much?


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## shred (Feb 9, 2009)

Macca  said:
			
		

> Thanks Shred, you confirmed my suspicions.
> I assumed the filler valve would have to extend below the steam outlet, which is where my thinking got stuck. I don't suppose it matters too much if the water inlet is above the steam outlet. Is there a risk of forcing water out of the boiler and into the engine when filling? And does it matter all that much?


Depending how the holes line up, or if you fill the boiler to the top, you can squirt some water down the steam pipe. Even if you fill the steam pipe all the way up, it pumps out in a few cycles of the engine when you flip the flywheel if steam is up (watch where the exhaust is pointing if it's not into the smokebox 'cause the squirt of hot water can go a surprising distance).


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## shred (Apr 2, 2009)

The black BBQ paint didn't hold up   Either the metal wasn't prepped enough or it just didn't like hot steam and oil, but after some big flakes just sloughed right off, I decided to repaint (which meant replumbing the shop air and making a new air dryer and.. and.. it's no wonder the Paddleducks engine is going slow ). This time I tried some Brownells Baking Lacquer-- supposed to be fairly tough stuff used to refinish guns and the like, so I was optimistic it would hold up to heat, oil and hot water. That it does. I've also noticed it's fairly brittle-- a few knocks and bumps and there are little flakes missing. You can see the corner of the cab took a hit in the pictures below.

I used "matte black", but I'd call it more of a satin finish, with a little bit of eggshell in it-- add a coat of oil and water as after a steam up and it becomes almost glossy. It's reasonably easy to apply, blast the metal (I used glass bead, AlOx is recommended), spray on several light coats, heating with a hair dryer in between and bake for 30 minutes at 325'F-- there's a little instructional video on the www.brownells.com web site in with the metal finishes.  It took almost the entire small can for the loco.

The rest of the smudges and spots are leftover dirt, oil and water from it just coming off the track after several paint-testing steam runs. Honest dirt, that.















​


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## J. Tranter (Apr 9, 2009)

Shred I have a question on the wobbler engine if it is OK.
 I a trying do figure out how far the holes are spaced for the intake and exhaust ports on the port block.
It doesn't show it on the plans. Also is the wobbler of set on the port block. I read Tony Birds build notes and It said something about it being offset but I didn't understand it to well, I'm more of a look and do 
than a read and do type.
Any help would be appreciated.
John T.


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## shred (Apr 9, 2009)

J. Tranter  said:
			
		

> Shred I have a question on the wobbler engine if it is OK.
> I a trying do figure out how far the holes are spaced for the intake and exhaust ports on the port block.
> It doesn't show it on the plans. Also is the wobbler of set on the port block. I read Tony Birds build notes and It said something about it being offset but I didn't understand it to well, I'm more of a look and do
> than a read and do type.
> ...


I don't remember the port measurements I used, but that's probably a good thing.. the exhaust hole was off a little until I drilled it larger. Dave Goodfellow on his site has a way to mathematically determine the hole spacing, but most people either do one of:
 1 - Make a little jig plate like in Elmer's Engines or
 2 - Make the cylinder and put a sharp rod in the steam port that barely protrudes and use that to lightly mark the path of the cylinder hole as you cycle it by hand, then drill both ends of the scratch (and re-flatten the port face to eliminate leakage along the scratch).

Mine is set directly centered on the block, but it's made a little differently than the plans since it's from bar stock-- the plans call for a K&S tubing cylinder soldered to a piece to be the cylinder, and another piece of flat stock with tubes soldered to it as the port face. I can't think how that would need an offset, but I may have missed something.


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## J. Tranter (Apr 10, 2009)

Thank you for your help. I thik I get it now.
John T.


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## vlmarshall (May 23, 2009)

Great build, Shred. Congrats on the win, and thanks for posting so many details of the build. You've talked me into building a pair of Crackers of my own. ;D


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## shred (May 24, 2009)

Thanks. It was such fun building and running this little guy that someday I'll do another little loco ;D ;D

Anybody with questions, feel free to post 'em here or send a PM.


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