20-5723-1 Milw. Road BiPolars with PS3
As I doublehead just about all my steamers, it made sense to doublehead two Milw. Rd. Bipolars (they did this in real life, as they did with many electrics). Unfortunately, one runs slightly faster than the other, or one runs slightly slower than the other. I first noticed this when running them independently, one of them had a very slight hitch in its step, forward direction only...I found a slightly loose motor mount screw, tightened it, and am not really sure it solved it or not...that's how slight the hitch or momentary hesitation was/is. Then, I set them on the same line and ran them both at 10 scale mph, and after about 60 feet the faster bipolar pulled ahead by about 24 inches.
Does anyone have a clue as to why this is? I didn't adjust any accel or decel rates.
As for doubleheading these two engines, I guess putting the faster one in the rear would be the best option, as it would be a pusher to an extent, though am wondering if that would wear the motor down prematurely? Putting the faster one in front would generate serious coupler tension over time...had that happen on steamers before...they were some strong couplers.