Reply to "WHAT’S ON THE WORKBENCH AT THE MOMENT"

I recently bought an Atlas SD-35 on that auction site. Good price and I expected some problems. First problem was the gearbox in one truck was bone dry and the worm wheel on the idle shaft as well as the worm was totaled.  Luck would have it that I had an identical chassis with motors also from that auction site which I purchased with several other such chassis for parts about five years ago.  So I had all the mechanical parts to repair the new SD-35.  Another problem that I intended to address was something I have had to repair on several other locos which had plugs on each end of the motherboard where the chassis ground and the center rail connected. When these locos jump the track you can get a short running through the traces on the motherboard which quickly burns through the trace. This can burn either center rail or outside rail traces. The outside rail traces are not as likely to short out as the center rail however on many locos the trucks are electrically isolated from the metal chassis/frame so the short runs through the motherboard rather than the chassis.  I have added PTC polyfuses to these locos to protect the traces on the motherboard. The photo was made after adding a center rail buss between the pickup rollers and the PTC polyfuse on that buss but before adding the buss for the outer rail conductors.  The wire is superflex silicone and can get very hot without melting the insulation. The connections to each end of the motherboard connect to the same place on the buss so the potential to each connection on the MB stays the same should one of the trucks derail and it's pickup roller gets grounded. I did the same mod to the connections to the truck frames also.  I do have a question about why the trucks are insulated from the loco chassis/frame.  Does this improve the signal to the R2LC ?   On some of my early pullmor TMCC conversions I made a ground strap from the trucks to the frame trying to suppress any arcing between the trucks and the frame. I am guessing that is the purpose here but seems it is much more complicated way to accomplish the same thing while making the trace on the MB more likely to get fried.    j