Shorts running MTH trains over Fastrack Operating/Uncoupling track...

Compare the "bulge" with other activating track. I had a PS3 ride up without shorting, but the plastic was swollen due to a button held on too long. The shorting must be a wire on the pickup touching the frame when pushed up too far.

The bulge is as it was new out of the box. I didn’t think about the roller touching the frame. I’ll look. Thanks. 

I had a problem with an MTH GP9 where the rollers actually caused the drive wheels to raise off the rails on some of my Super O switches. My solution was to swap in smaller diameter roller assemblies from MTH, part# BD-0000097. Problem fixed!

Rich, thanks for that info. I had no idea I could do that. 

Ed, that part number is for a single-arm roller assembly. I decided to try these because a later model RS3 that I purchased new had this particular roller setup and never had a problem on any of my switches. You should check to make sure they will work with your engines. I'm planning to swap them on an E6 A unit that I recently picked up, too.

I used a Dremel to grind the bulge down and cures it and doesn't effect how it works. I've had that happen with MTH engines. I've had one that it would bounce off the track at any speed. It was a fiber cutting disc or the sanding drum. Can't remember but I would say the fiber disc.

Thanks. I wasn’t sure if doing that would damage the track. 

Riverrailfan posted:

Thanks for the photo...great help.  Did you lower the center metal piece as well, or just the plastic ramps...? 

I ground the center metal piece. Try not to grind the plastic at the center rails.

Well, i did my grinding before I read your latest.  I did both. But I did in a way that left a short run-up to the metal. I just finished testing my engine and it ran fine at lowest speed in both directions over the track and the operating and uncoupling functions work perfectly.   Once again a big thanks.  It's always a confidence booster to know someone else has successfully completed a fix.

And an even bigger boost when you can fix it.

Absolutely. Too often I make things worse. Not this time. :-D

Even mine still had a hump. Glad it worked out for you. 

Greg

I’m having a similar problem. Shorts at any speed going over it. When I remove the jumper wire underneath the track for the asc2 rewire it stops shorting. However then the asc2 won’t turn it on.  I must be doing something wrong.  Wondering if you guys can point me in the right direction.  Thank you

I also had this problem. In my case I modified the engine, so the center pickup rollers could retract completely into the truck, thus no longer lifting the truck off the track and stalling the engine.

I have attached my modification procedure for your reference. You can use electrical tape or thin plastic to keep the roller from shorting on the frame. The key is to use an insulating material that is thinner than the plastic supplied with the engine.