Rebuild Version 3

The positioner push bar is changed to a coupler grabber - semi-prototypical AFAIK, no push bars are used... they would smash real train cars :) The dumper pit bottom is cut out more and the ramps are now supported with metal rods. Hopefully this will alleviate 'coal' residue building up on the edges, rather than falling into the pit.

Getting the grabber to actually work is a problem, as there seems to be a wide variance in what the servos actually do : sometimes the 'brake' lifts the car into the air and other times it does not rise far enough to correctly position the car. This (and the positioner seeming to stop at different positions) affects where the car(s) are and thus the coupler grabber sometimes misses that thin divide between the coupler and the box support behind it. Hitting the coupler - rather than its attaching rod, or the box support causes the servo to grind and not actually 'grab', thus when the car is moved it stops in a wide range of positions :(

i dunno, might end up going back to the push bar - it seemed to be doing ok after changing the code to jiggle the car after stopping. ... but the coupler grabber sure looks a lot more interesting and realistic.

will keep trying to adjust things, however, being this finicky leads to a lack of repeatability - having to adjust things (for hours?) every time a train is dumped does not seem practical.