Loco Repowering

"Russell J Postlewaight" <russell.unfire@...

Hello from New Zealand, Home of the Americas Cup.

Ken Clarke, Thomas Beutel and others have made some great points regarding fine tuning and repowering of locomotives.

I model NZ Railways in Sn 3�, where one of our narrow gauge AB class pacifics loos to be about the same size as an HO scale Espee GS4 4-8-4. That is about 11� inches long and 2 inches high so add to that we also run on 16.5mm gauge track youll get some idea of the size of our locos.

Standardising on a drive system is an excellent idea and I use Sagami can motors with 36:1 North Yard double reduction Gearboxes. North Yard is a New Zealand firm who market a large range of scratchbuilding and repowering componentry of a very high quality. The RP25 locomotive and rolling stock wheels they manufacture are as good as if not better than Kadee quality you Americans enjoy only at half the price. Anyway most of my units use the 1630 Sagami motor with the gearbox fitted to the extended drive shaft. This appears to solve most of the alignment and gear meshing problems encountered with open framed motors and some of the lower priced gear arrangements such as those employed by Mantua and Roundhouse. The motor is then mounted to a brass mounting plate attached to the frame by two 1.4mm screws to the holes provided in the motor case. Provided you keep your motor exactly to 90� to the driving axle and the driving axle at 90� to the frame there will be no problems.

Ken made the statement about tuning before painting. I agree entirely. For some unknown reason, no matter how hard you try painting your locomotive will require you to retune everything after reassembly.
Perhaps this is one of these things that makes this hobby so much #*@$)(? fun?.

I also agree with his comments about longevity. I have a NZR A class pacific I built about 14 years ago with the drive system above in it and I've done no maintenance to the motor or gearbox but I now find myself about to replace the driving wheel crankpins.

Kind regards
Russell Postlewaight.

PS On a completely irrelevant note: can any of you people put me in touch with any fire apparatus modellers? My other hobby.