Time to decide if you are going to modify the 3-cylinder to a 2-cylinder power plant. This is not a simple task. You need to be very careful so you don't break or lose any of the small parts. You also need to figure out what you are going to use for the two cylinder power plant and where and how you get the part.
You also might just decide to use a 3- cylinder power plant, the one that comes on the Atlas, or some other3-cylinder. The HO or HOn3 MDC Shay 3-cylinder power plant might also work and you might modify the MDC 3-cylinder to a 2-cylinder power plant.
I have several of the Toma HOn30 Shay engines and used one of the 2-cylinder power plants from them. To make it fit I had to cut away the Atlas Shay 3-cylinder power plant just above what looks like a tube of some sort going from left to right. I used that more or less a cutting guide.
To use one of the Toma Shay 2-cylinder power plants I had to cut off some of the lower part to make it fit the height limits I had.Then I glued it to the modified Atlas power plant backing plate.
This drawing shows the back of the bracket that holds the power plant and line-shafts. This is a 2-piece thing so try not and let it come apart or the line shafts will fall out. You can get them back together, maybe. I was able to put it back together on the third or forth try the first time it happened, but I did get better at it. If the part comes apart to many times you can wear the plastic pins that hold it in a nice tight fit and it will no longer stay together. That happened to me but I was lucky and got a new part from Atlas. They don't stock parts but I was lucky and they found the part I needed on a Shay that had been returned broken. As it turned I didn't need the new part. I was able to glue the bracket back together but if you have to do this use no more glue then necessary.
If you see the three tooth pick looking rods between the two bracket pieces, those move up and down or should unless you get glue or paint on them. The crankshaft turns with the trucks on the line shaft and should make those 3 rods go up and down, maybe. If you do something and the line shaft does always turn I wouldn't worry to much. It is small and hard to see it turning when it is working.
The top part of the bracket where you cut off the top part of the 3-cylinder power plant is where I glued the 2-cylinder power plant.
Looks like the Toma Shay isn't available for parts these days so cutting one of the cylinders off the Atlas model may be the only way now. That should be possible and also possibly blanking off the third con rod aperture so that only two in motion are visible. I reckon my eyesight might need a boost for that though!
The first power plant (on the right side) is the modified version of the Toma part, shortened a bit. The second is the way the Toma power plant comes and the third is a modified version of the MDC HO or HOn3 Shay 3 cylinder power plant. I think the modified MDC version is to large for HOn30.
This is the Toma Shay 2-cylinder power plant on an early version of my Shay conversion.
How about a white metal boiler and maybe a white metal 2-cylinder power plant. This is just a rough draft of the boiler. The boiler is a left over Keystone Shay boiler. Just testing to see if it I can make it fit and not short out anything. As a plus the white metal adds some much need weight to the Shay.
slateworks wrote: Watching - watching! Those Toma parts look very good, much neater than I could do with styrene.I agree, the Toma parts are excellent and I had a true master build and paint them for me.
I bought 5 Cabs and 2 Fuel Bunkers extra while they were in stock so I have now used both of the brass etch Fuel Bunkers.
I might try making more of the Fuel Bunkers out of card stock and see how they turn out.