Bachmann Spectrum Split Frame Insulators

[CoolRuehle]

Any ideas on where Bachmann Spectrum split frame insulators?

I checked the online parts section of the Bachmann website -- no dice, just a bunch of Thomas the Tank Engine parts. (I wish I could find the late Mr. Conductor) :-)

I need an entire insulator set. I installed a Digitrax Decoder tonight and two of the Tee-nuts and one of the center insulators split. One of the plastic engine insulators split as well, abut I managed to make that work ok. This plastic is very brittle and of low quality.

If anyone has any ideas on a retrofit plan, that would be helpful as well.

Thansk!

--Jon

[Jim Banner]

In a pinch, you can make your own.  The center, cylindrical part does not have to have a square end - you can use two screws instead, as long as their ends do not touch in the middle.  Try a piece of 1/8" styrene or pvc tubing.  If it is a bit loose, wrap a bit of Magic Mending Tape around it.  Drill and tap the ends for #2-56 machine screws or use #2 self tapping screws.  For the insulating washers, drill a hole in a piece of .030 or .040 styrene sheet, using a drill that will barely fit through an original washer.  Then use a 1/4" hole punch to cut the outside diameter of the washer, looking through the female half of the punch to make sure the hole is centered in your washer.

I suspect the problem with the originals is not so much bad plastic as worn moulds.  The more the moulds are used, the more the pin that makes the centre hole in the casting gets worn down.  The smaller the pin, the smaller the hole.  Eventually the hole gets so small that even the correct sized screw will cause the casting to split.  I suspect that at least some of the pieces split when the locomotive was originally assembled.

The hardness in old injection moulded styrene parts is more likely a result of over heating.  That can make them much harder now than when they were new.  So when putting screws back in, it is imperative that they go back into their original threads.  Forcing new threads in hard, old plastic is a recipe for disaster.  Better to use the old trick of turning the screw backwards until you feel and/or hear it drop into the old threads, then tighten it gently.

The ultimate solution is to machine new T-nuts out of an engineering plastic like PVC or Acetal.  This is not too hard if you have a lathe and/or a milling machine but cost prohibitive if you have to pay to have it done.