14 May 2015: Just added the pictures with captions. The underside of the 90-cross section is probably the most interesting. TRRR
Scottransam, thanks for the drawing. I'll attach a photo of the change I made last night. Very similar and I actually like how it changed the space and may allow for a freight yard build out. (I like the way you extended out around the basic layout.)
As Carl/Moonman has noted there are likely multiple issues here. So, separating the cross and switch track sections will help identify what's going on. I'll add separate responses too in order to clarify each. This one's for the SD-70 and the cross.
#1: The 90-degree cross section. Attached is a photo of the underside. There's copper latticework connecting the three rails in both directions of the cross arms. Notice there is a single jumper wire going from what I'll call the south arm of the cross to the east arm (when viewed from the track side). It is clamped to the center rails. The SD70 stalls moving from the south to the north.
Using my Bethlehem Steel ruler :-) on the top of the track, I see that the center plastic square is 1/32 inch lower than the plastic pieces that surround it. So, there's a little low point for the roller. The overall impression looking at a side view is that the track where it joins the center square bulges upward on the four sides and then the center piece drops down that 1/32 inch.
When the engine shutdown again last night at a slow speed, the front roller was just about to leave the plastic square in the middle of the cross. The rear truck was about 2/3 through the curved track section attached to the bottom of the cross. The truck had swung out so far left that only the right-most metal hanger that holds the roller to the underside was touching the center rail. So, it looks like there is a case for a moment at least when both rollers have no power. Mannually pushing the engine forward a short distance powered it up again as it now had contact. I've recreated the roller positions on the track. (Sorry my camera is really cheap but my backyard trees are nice!)
Solutions? Jumper wire or metal plate? I'm holding off on adding a lock-on to the inner loop (thanks for the further explanation) because that requires ordering yet another part. I want to get a multitester this weekend so I can better observe what's going on volt-wise and where in the track first.
Tomlinson Run Railroad
** RATS! My photo uploads are failing and I have to head out now. The text should explain things well enough. Will try this evening and then post my discoveries about the switch and both engines now that it's been separated from the cross. **
