Some recent work on the In-ko-pah RR

[TRAINS1941]

Very nice Ray.

Jerry

[Ray Dunakin]

First off, I found a pair of websites about restoring an engine almost identical to this one:

http://www.eldensengines.com/F-M%20Power%20Station/F-M%20Power%20Station.html

http://www.coolspringpowermuseum.org/Exhibits.htm


I learned a lot about the engine from from these two sites. For one thing, it's a 300 horsepower Fairbanks Morse opposed-piston engine, probably model 38F5-1/4. This type of engine has two crankshafts, one at the top and one at the bottom. It also has two sets of pistons, which face each other in the cylinders. Also, the large thing protruding from the top front, which I'm currently working on, is a supercharger.

In addition to powering generators, these types of engines were also used in locomotives, submarines, and surface ships.


Anyway, I've mostly been working on adding all the details to the supercharger. The air filter was made from a short segment of 5/8" styrene tube, with a piece of 1/2" tube stuck into it. An acrylic, elliptical dome was used to make the rounded bottom of the air filter (shown bottom up in this photo):




I cut another segment of 1/2" tube and cut a slit in it, so I could wrap it around the first tube. Later I cut a piece to fill the gap:




A few years ago I bought some photoetched mesh with round holes, thinking I'd find a use for it eventually. It turned out to be perfect to replicate the mesh on the air filter:




I cut a strip of the brass mesh to the proper width, then wrapped it around a much narrower tube before installing it on the air filter. I sealed the ends together with tiny bit of thick CA, which was enough to hold it in place. Then I topped off the air filter with a styrene disk to represent the lid. I still need to add the bolt to the center of the lid:




Here's how it looks on the supercharger. I haven't glued it in place yet, it's just sitting there. The other details were made from various bits of styrene tubes and strips:







Here's the whole engine so far. The orange piece was made from the bottom of a prescription pill bottle:






That's all for now, more later.

[Greg Hile]

Wow, this is shaping up to be another masterpiece. And prescription bottles! I've been saving them without knowing why and you just gave me an idea for the fire pole assembly for a fire house I am designing. Thank you!

[finescalerr]

I think you forgot the timing chain .... -- ssuR

[1-32]

alright, ray.

[Lawton Maner]

Russ:
An engine of this size and age most likely has its timing driven by a gear train which is inside because of its need to be lubricated at all times.

[finescalerr]

I was kidding around about the timing chain. I don't even know what a timing chain looks like or does! -- Russ

[Barney]

Looking good Ray and the engine coming on nicely to
Barney

[Lawton Maner]

Russ:
A timing chain looks like a bicycle chain on Steroids. 
It connects the crankshaft with the top of the engine so the valves open and close "in time" with the motion of the pistons.  Most new cars have a timing belt which over time stretches and has to be replaced.  The last thing you want is for a valve to be open so a piston crashes into it as it speeds to the top of its motion.

[finescalerr]

Thanks, Lawton. Now I finally know their function. I think I've seen timing chains on old car motors in engine rebuilding garages. -- Russ

[Lawton Maner]

Russ:
If you keep learning one thing a day, your mind will never grow stale.
For Ray to allow you to see the chain, he's going to have to model the engine under repair with the cover off which is far to much work.

[Ray Dunakin]

Apparently this type of engine didn't have a chain anyway. It was all done with gears.

[finescalerr]

Nonsense, Ray. They were made of plastic, as your recreation clearly exhibits. -- ssuR

[Ray Dunakin]

A few days ago I posted this photo of a styrene test piece for the covers on the engine:




My plan was to make a rubber mold and cast these things in resin. But that test piece was too rough. Well, I tried a couple more and couldn't get it to look as good as I wanted. So I tried a different approach, making it out of 1mm Sintra and scribing the indentations. That turned out even worse:




Even if I could have created a suitable master, I had doubts about how well such thin pieces would reproduce as castings. So I scrapped the whole idea and decided to come up with a non-prototypical design that would be simple enough that I could make all 20 of them individually. My first test of this was extremely simple, just a flat piece of styrene with rounded corners and a nut/washer in the middle:




But I felt that this was TOO simple. I wanted something that looked a bit more interesting. The design I settled on was made by layering two pieces of .020" styrene. Both pieces had the corners rounded, and I beveled the edges of the smaller piece before gluing it on top of the base piece. Here's how they turned out:








I also did some work on the base for the engine and generator:








.

[Design-HSB]

Hello Ray, that promises to be a very appealing model again. With good suggestions for the replica.