Was wondering if anyone has found brass flywheels that can be installed on the Kato HM-5 motor? And if so, are they press fit or do they need bushings. I have access to some HM-5's but would want flywheels.
Or does anyone know the diameter of the motor shaft on the HM-5?
I haven't purchased any 3rd party flywheels in a long time. A-Line used to be the main supplier and I assume theirs have a 2mm opening, to fit their Mashima motors.
The Kato motor shaft is rather soft unfortunately and unless you have the right tools, pressing on flywheels isn't a good idea. I bent a motor shaft (thus destroying the motor) trying to press on flywheels.
Older Atlas stuff uses a brass flywheel with a delrin bushing that will fit a 2mm shaft. They don't have the hex opening on the outer end however.
If you can get the Kato motors with the flywheels already attached, that's usually the best way to go. More expensive and availability is more sporadic, but it's a real time saver - unless you require smaller length flywheels. My last motor swap was on an Atlas C420. I wasn't able to get the Atlas flywheels (2 different sizes) off the motor, so I wound up using the Kato motor with the big flywheels, and just grinding the hell out of the chassis to make it fit.
Atlas downsized their flywheels in between the first and second run of SD35s - circa 2002 I believe:
And now they've gone to an even smaller flywheel on one side to make room for the speakers (C420 Silver Series):
Basically this means some grinding and chopping or complete removal and restructuring of the weight to get a Kato motor + large flywheels in place.
My next remotoring project may not be burning up any decoders but it sure burns a lot of oil. And premium:
Kato was out of HO motors for quite awhile and just got in a 1000 of them about 3 months ago. I spoke to their tech support and they make up the motors with flywheels as needed. They are in stock right now for $35.00@.