Guys, thanks for all the kind comments on my project, this is my latest progress.
I installed the spoked wheel covers, and the connecting rods using the rivets and the small caps from the TGauge.com valve gear sheet. Just by cutting the rivet it held the cap in place. However, I added the smallest drop of CA just to be sure it will hold up over time. Working with these small parts is insane work. I am calling it Extreme Steam Craziness.You need extra rivets and other parts as you are bound to lose some during assembly!
I also learned lots more from my tests with the 3.2mm motor. The rear magnets are very close to it, and seem to have an effect on the locomotives performance. I placed the magnetic rings from the rear wheels on my soldering iron for a few seconds, and that demagnetized them. Placed them back on the wheels, and the locomotive is running very well at this time. In fact I found that all the model really needs it two wheels with the magnetic rings to be efficient. I am using them on the center wheels on my first prototype, the other wheels have rings that are demagnetized. This is with the 3.2mm motor. The 4mm motor has more power and may work better with them. I plan on building a second model with a 4mm motor to test this out when I get time.
I moved the spacing out slightly so the valve set would fit. I was hoping that the extra gap would still give me enough gear mesh and it did. However, I think that your spacing may even work, but you would have to test it.
I did run it with only one driven pair of wheels, and she ran well. I would also like to mention that she ran with the three magnetic wheels attached. It really glues the engine to the track as you can run full speed and she would never come off the rails! My problem was after running for 30 minutes or so the engine was losing performance. I removed the rear magnetic wheels and she ran great again. I think with a 4mm motor I would go with two sets of magnetic driven wheels. The middle and the front ones. However, I would test this first. I was going to draw up a new chassis to fit the 4mm motor, but decided to give the 3.2mm motor a shot since I came this far with the project.
I had a little problem with my 3.2mm motor chassis after I installed the connecting rods. The wheels were slipping, and the rods were jamming. I tried gluing the wheels in with CA, and 5 minute epoxy without success. I had to build a new chassis, so I redrew my design for a 4mm motor, as I wanted a little more power. The 4mm motor just fits my Pacific Locomotive body. I want to mention that I used the TGauge.com axles, but the steam wheels do not fit into the holes. I had to drill them out to get them to fit, causing the wheels to slip. However, after I completed my new chassis I found a glue that worked well. I used a small amount of Gorilla glue.
I used 4 magnetic wheels on this version on the middle and front axles. The rear wheels have two demagnetized rings on the wheels. This chassis runs great with lots of power. I am using a 13ohm 4mm motor. I installed the connecting rods and simple valve gear. The model is a scaled down version of one of my favorite Zscale locomotives.