Cab Forward 2020

[bob turner]

One is 24:1, the other is 25:1. The drivers do slip, and the motion is periodic. The mind has a difficult time seeing the periodicity over such a long period - I have tried, and it is not at all obvious even if you know what to look for.

I can find no loss of traction due to the slip, although it is not insignificant - 1/25 over four inches of surface or so is something like 1/8" per driver revolution.

This is a much better solution than the two motor, independent gearbox idea. Clean, quiet, powerful.

[R.K. Maroon]

Very interesting. Thanks for the explanation. Credit to you for experimenting, as I would have considered it not viable.

I have shied away from articulated locomotives, but only because I did not much like the amount of overhang that they showed on our local club layout. I have left enough space in the new shop (now under construction) to increase the radius of curvature. If that happens then it might be enough to motivate me to finish this project:


This is a General Models / All Nation 2-6-6-4, modified with a Belpaire boiler a la Pittsburgh and West Virginia. One weakness with these is the single engine drive:


Bob recommended that I "don't bother" with this drive as it is, but to find a pair of NWSL gearboxes, which I have. Nonetheless, I am pretty sure the project will sit as it is until such time as wide curves become available, if indeed they ever do.

Jim

[J. S. Bach]

I suspect that if you do not have any steep grades and do not run excessively long trains, that single drive will be just fine.

[bob turner]

I have empirical evidence that that is not true. For some reason not totally clear to me, these things have a difficult time just pulling themselves around a flat layout. You would think that the front engine would be a lot like an extra freight car, but for some reason it sucks the life outta these things.