VINTAGE 2Rail-?

The rubber grommets used in the old motor mountings were to minimize any vibration and noises from the motor or the drive line. The brush contacts for the motor and also its field are already insulated from the motor's frame.

Newer 'can' type motors run much more quietly with less 'cogging' of the armature than the old motors did. So they usually do not require that sort of isolation from the locomotive frame. Still, if the modern motors can also be isolated that way, they could be even quieter in operation.

Ed Bommer

Precision Scale Corp may still have those robber gromets.

"PSC"

Your local hardware store or big box home improvement will have the rubber gromments. I've bought them before for other uses.

My favorite motor mount is a chunk of brass tube screwed to the tailbeam, with a sheet of old inner tube Goo-ed on, then the motor goes on top of that, aligned with the drive shaft, and held with aircraft safety wire. All the U joints on my steam are sent to dead storage or diesel use, and the steamers get Toyota #O vacuum line to transmit rotation to the worm shaft. Dead quiet.

But those grommets are still standard hardware.

Hi Jim,

I am in the UK and am currently restoring a Max Gray/KTM Big Boy. The job has come to a halt for the same reason the motor grommets have perished.

I wonder if you solved the problem? While lots of grommets are available the KTM size was unusual certainly over here.I wonder if you followed up the PSC link? 

Dennis

Jim,

 

I have purchased grommet assortments from an electronics supply house in Baltimore that included grommets of the size used by KTM.  However, at an O Scale meet  last year, I purchased several packages of original KTM grommets (4 per package) and they appear to be like new.  If you cannot find a suitable replacement in a local hardware store,I can send you a package of the KTM grommets. 

 

If you are going to install a can motor to replace the original KTM open frame motor, as Ed Bommer pointed out, you probably do not need the grommets,

 

I have remotored a good number of engines with various can motors and seldom if ever installed gtommets.

 

Joe Foehrkolb

I bought matching rubber gromets at the local hardware store.

Hi Joe,

 

Thank you for your advice and kind offer. I have today made up some temporary grommets from rubber sheet and a hole borer. At least I could check out the motor.

I will spend a little more time trying to find a replacement. Although I build O gauge from brass/nickel kits I am new to US O gauge. After a few weeks I have only just managed to prove the drive wheels were insulated! Becuase I could not see any obvious insulation I assumed there weren't. However an ohm meter proved otherwise. I may possibly replace the motor as another suggestion. Although here in the UK we have a good selection of O gauge suitable motors I suspect they may not be 'man' enough for the BB? More searching I suspect.

Again thank you for your help and kind offer. See how I get on in the next week.

regards

Dennis

Hi PRRJIM,

 

I have had a good browse on eBay and whilst there is an enormous selction the original of 4mm bore and 8.5mm hole size seems unusual. However I will try again. Thank you for your reply.

 

regards

 

Dennis