Large Scale Central

Bachmann 10-Wheeler -- Dead on the Rails

Problem Solving
#1

North Star, a Bachmann 10-wheeler with an upgraded chassis and frequent character in my repair posts, went dead the other day pulling a string of three U.S.-style LGB coaches. Unlike previous failures, there was no whine indicating to suggest a split gear ( Bachmann 4-6-0 Periodically Stops and Whines) and there was no headlamp light which did suggest the break was coming from someplace closer to the drivers than the internals based on a previous incident where the soldering gave way at the motor tabs. I also vaguely remembered that one of the hard points that holds the bus carrying 'trons from the drivers to the internals had required some CA bracing somewhere along the line.

Given the above, the 1:24 gang and I cracked “him” open. Sure enough, one bus had broken free. The screw and plastic shard are on the wood block:

20230331_145503
20230331_1455031920×1440 310 KB

Here is a closeup of the broken hardpoint:

20230331_145531
20230331_1455311920×1440 286 KB

I also put an ohmmeter across the leads that lead into the internals. It didn’t go to infinity, so I am assuming that things are good “downstream” of this. I could be wrong, but this needs to get fixed.

Before proceeding, I wanted to sanity check my plan.

  1. Grind out the broken hard point.
  2. Glue in a wooden shim.
  3. Replace the bus.
  4. Use a little woodscrew to hold the bus to the shim.
  5. Button on North Star and test “him.”
  6. Based on the results of the test, either enjoy “him” until the next failure or take off the cab and boiler and continue with troubleshooting.

Thanks for the vector check!

Eric

#2

If you have some plastic tubing you can drill out the center of the broken mount tab, cut a piece of tubing to slide into the (same size) hole you drilled, glue the tubing in place,cut it flush with the top and then run a self tapping screw through that. However it looks from the picture that you should have enough material there to run a self tapping screw into it like it is just pre drill a small pilot hole. Oh and reading the title “If it’s dead on the rails” get it off the rails before Kidzilla’s Amtrak comes blowing down the main!!

#3

Looks like the CA gave way and let the screw pull out. Either the piece of wood or Rooster’s suggestion of putting a tube into the remains of the stub will work.

A better mechanical solution would be to bolt right through the base and put a nut on the top. Not much clearance though - especially underneath?

#4

Pete & Rooster:

Thanks. I took a good, hard look at the part in question. There was insufficient “meat” let for the simlplest solution, a self tapping screw, and I worried about clearances if I went with the best mechanic mechanical solution and attempted a bolt and nut. Adding to my material worries, the plastic on this whole loco is getting very, very brittle. I decided to go with the wood shim, first grinding out what was left of the original post…

20230401_172224
20230401_1722241920×2560 403 KB

…then using E6000 - the second best glue for everything - to affix my shim.
20230401_173346
20230401_1733461920×1440 229 KB

Tomorrow, I will root about for a small screw, like the type to mount hangers to picture frames, so I can button North Star up and put “him” on the rollers.

Thanks for the vector check!

Eric

#5

Quick update…

Some Dremel work, a small wood block, and, of course, solder to repair a snapped wire later and I had everything good to go.

20230402_154200
20230402_1542001920×1440 243 KB
20230402_152947
20230402_1529471920×2560 471 KB

Oldest Son prepped the test rollers, and it looks like North Star is ready to run until the next piece breaks!

Video: North Star On the Rollers Ready to Serve Again!

Thanks for the assistance!

Eric

#6

Suggestion. The recommendation is go to your local hardware store and purchase JB Weld. It is a 2 part machine-able (sanding, carving work) material that bonds to a variety of materials. Once mixed according to instructions it holds better, is stronger than many glues, is generally non conductive although there are multiple versions with a variety of hardening times. Your original post problem by have been able to be solved by filling the original hole with a collar made of tape then drill a new hole.

This is not a unique problem and it will rear it head again in the future. I have even taken small parts, cast a mold around them using play dough and then when the JB is set sand or otherwise rework the casting as appropriate. These casting are typically under an inch in size.

#7

Mike,

Thank you very much! I have seen this product at our local hardware store. I’ll have it on hand for the next time!

Eric

#8

You can use a plastic straw as a mold