Something else to look into. The power pickup from one side is transferred from the truck bolster to the frame just from the frame sitting on the truck. I found a film of oil on the truck bolster where the frame rests on it. You could clean and file or sand the truck bolster and the frame, or solder a wire from the truck bolster to the frame. Use a small gauge wire that won't bind up and hinder the movement of the truck. That will give you positive power pickup to the truck.
It has new nylon motor mounts, as another unit needed them replaced, and I still had the extras from the new set (pkg of 8 new ones) . I will have to check to see if it's twisting though... And I did make sure there's no electrical contact to the frame, mounting wise anyway... So unless it's twisting slightly... Thanks for that info, I will have to check that out.
Ricky W.
HO scale Proto-freelancer.
My Railroad rules:
1: It's my railroad, my rules.
2: It's for having fun and enjoyment.
3: Any objections, consult above rules.
When you removed the motor to install the decoder, what condition were the nylon motor mounts in? Athearn has finally wised up and designed new motor mounts that are held in with screws instead of being a friction fit.
If the older style mounts are not firmly in place, or are so old and dried out that they allow the motor to move around, it can cause binding like you describe.
I use the new Athearn motor mount package, item 84028, for all installs even if the old mounts are not deteriorated.
Another possibility: When you replaced the motor, did you put electrical tape between it and the frame? There may be a small sliver of metal sticking up from the frame and touching the bottom motor brush contact if you didn't use insulating tape, or the motor could be twisting sideways in the old motor mounts and touching the frame.
What condition are the motor brushes in? I've had to put new brushes into some of the older Athearn locomotives as decoders were installed.
Yeah, Motor is isolated with tape, clips flipped, top to bottom, bottom now on top. I'll try the black wire onto frame. It did run on DC, just test section though, a little jumpy on slow speed, but I thought the clean and polish would fix that, could that show another issue? Thanks for all the tips so far.
The black wire on the old light post is probably the problem, the post is riveted to the frame and usually they are kind of loose. You can drill and tap a hole int he frame inside the shell and put in a brass screw and solder the black wire to that, or even better would be to solder wires right to the metal portions of the truck sides so as to not have to rely on the bolster to transfer power.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Be careful that the motor isn't maxing out on amps and the decoder is getting overloaded.
Richard
Is the bottom motor/ brush clip totally isolated from the frame w/ capton or elec tape? I switch the clips to place the pronged bottom clip ( frame contact for bottom brush) on the top. Prong can perforate the isolation (tape).
Modeling B&O- Chessie Bob K. www.ssmrc.org
You may just have a really stiff mechanism. Does it have much running time? If not, I'd suggest removing the decoder and doing some break-in running on straight DC on a loop or test stand until the driveline components loosen up.
I had an Athearn mechanism that literally wouldn't run even on full 12 volts DC due to how stiff it was at first. I had to manually coax it along for several minutes (by turning the flywheels) before it started to run on its own. With a few hours of break-in time in each direction it was fine.
Rob Spangler
Thanks for the tip... Okay, It's an HO scale Blue-box GP60, with a hard-wired Digitrax DH123. Red wire is connect to both front and rear trucks, black on frame post from old light. Orange-grey to motor, and LED's on white/blue and yellow/blue. I dis-assembled, cleaned and polished the trucks contacts, as well as the frame contacts. It does have power, as the lights work. But even at full throtle, the motor only hums. If you spin the fly-wheel by hand it moves a little, but then stops again, but the lights stay on. nothing in the trucks is binding-up, and I am unsure of what else to look at, any ideas???
You also have a computer software problem.
If you're using Internet Explorer, go to the top of the page where the URL appears and click on the icon that looks like a sheet of paper torn in half. That will put IE into "compatibility" mode so it works correctly with these forums.