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Re: Decauville 0-4-0 1:22.58 Scale

Posted: Thu Sep 17, 2020 5:29 am
by diddler
I finished the engine and linkage install this weekend, The little bugger ran perfectly on 20 lb of air. I am going to change he piston design to accommodate two teflon seals. this will give me a better seal in the cylinder. I did wind up putting a small hole in the bottom of the stack to allow water to drip out. This hole is around .050, I am sure that there will be not problem with the draft.

Re: Decauville 0-4-0 1:22.58 Scale

Posted: Thu Sep 17, 2020 6:44 am
by diddler
This is a shot of the Locomotive with the engines and linkage installed sitting on some make shift rollers to check function. All worked well from the start.

Re: Decauville 0-4-0 1:22.58 Scale

Posted: Wed Sep 23, 2020 6:33 am
by diddler
So this weekend, I redesigned the piston/seal assembly for the engines. If you look at the drawing, the piston is shaped like an (H) looking from the side. The seal was a split seal with oil grooves cut into it. I cut the end of the piston off ( One of the ends of the (H)) and made two seals out of teflon that resemble an oil seal, The two seals were installed facing the direction of the input of the cylinder. The part I cut off the (H) was then made to screw on the end of the shaft locking the assembly together.
With this setup, I could run the locomotive at 10 lb of air pressure on the first notch off center both forward and reverse.
I have pictures, but forgot to send them to my work email to send them up, I will do this soon.
Also started building and welding the boiler, Oh joy    

Re: Decauville 0-4-0 1:22.58 Scale

Posted: Wed Sep 23, 2020 7:52 am
by Pontiacguy1
Sounds like it is going very well! Keep going, and it will be done soon. If a new locomotive can run square, on 10 PSI, and doesn't clink or clack around, then it's probably built pretty well. Good job!

Re: Decauville 0-4-0 1:22.58 Scale

Posted: Wed Sep 23, 2020 10:15 am
by diddler
Thank you for your kind words Pontiacguy, I am very happy for what it has become, being for my first one ever. Before I redesigned the piston, I could press down on the locomotive when the wheels were turning at a low speed and the wheels would stall, Now I can press down very hard and the little bugger keeps chugging .

Re: Decauville 0-4-0 1:22.58 Scale

Posted: Thu Oct 01, 2020 10:08 am
by diddler
Well it has been a few days but I offer the following:
The first image is the old way the pistons were made , although the cylinders ran ok like that, I didn't like it so I made the pistons with the seals I made in the second pic. Much better seal and the locomotive would run down to 10 lb
The third pic is just the engine assembled
The 4th pic is the engine mounted and timed.
The last pic is where I am at in the boiler assembly, I did make the decision to use steel.

Re: Decauville 0-4-0 1:22.58 Scale

Posted: Mon Oct 05, 2020 9:11 am
by diddler
I was just a little board today so I built a scale Steam Locomotive Head Lamp, Just need to add the glass and paint the inside white. Just for a moment I had a thought to make it function but soon lost that idea. :lol:

Re: Decauville 0-4-0 1:22.58 Scale

Posted: Mon Oct 05, 2020 10:44 am
by NP317
Nice detail.
RussN

Re: Decauville 0-4-0 1:22.58 Scale

Posted: Wed Oct 07, 2020 7:47 am
by diddler
Thank you RussN, I am doing everything to put off Silver soldering the boiler, Just don't want to make a mistake, just a little too much heat, and it is all over.

Re: Decauville 0-4-0 1:22.58 Scale

Posted: Wed Oct 07, 2020 10:07 am
by NP317
I understand that psychology...
Review Kozo's silver brazing techniques. Those are good to have in your head.
RussN

Re: Decauville 0-4-0 1:22.58 Scale

Posted: Sat Oct 10, 2020 4:51 pm
by diddler
Can anyone give me an idea of the working pressure of this boiler I am about to partake in the assembly of. Of all the information I have, this I have nothing on, I do not have any information to adjust the relief valves at. Any information would be of great help.

Re: Decauville 0-4-0 1:22.58 Scale

Posted: Mon Oct 12, 2020 9:14 am
by Pontiacguy1
Most small scale locomotives in 1/2" scale 2 1/2" gauge ran on 100 PSI. A lot of your early small scale stuff was 100 PSI, even in 3/4" and 1" scales. 1 1/2" scale is usually 120 PSI. However, you might not need that high of a pressure. I would probably start off with 80 PSI pop off point, and see if it does well there. Smaller scales like garden scale locomotives (gauge 1) sometimes ran on a lot less, down to even 40 or 50 pounds max working pressure sometimes. They are not expected to pull passengers, though.

That's the thing: With 2 1/2" gauge being considered the crossover point between scenic garden railways and ride-on passenger hauling railways, they could be built either way. I've seen more of them built using similar methods to 3/4" scale and 1" scale locomotives, but there are a lot that are built using methods and fuels that you find in the garden railways too.