I've been puttering around my workshop, trying to find a decent (and cheap!) stardard guage engine for my Caribou lumber company to work the switchback. In my collection I've aquired 3 of these MDC clmaxes. For those of you unfamiliar with these little beasties they were designed in the mid-sixies and the design has never changed. They are powered by a 5-pole open frame motor screwed directly to the zirmac cast frame. Coupled to it are a plastic motor gear, followed by a brass idler gear and a large 'bull' gear that turns two very short universals under the frame to to trucks which are then driven by jack shafts with brass work gears and a gear on each axle. The design is simular to MDC's shay.
While the design to strong, and the engine will pull like a mack truck, the noise that comes from it is considerable probably due to a few things:
1) the bull gear sits quite lose in the gearbox, allowing it to move back and forth and 'rattle' in the box.
2) the open frame motor is mounted (screwed) directly onto the frame, trasmiting all the motor noise to it.
3) the fact that the motor has to turn at high speeds for the engine to get up to speed. Granted climaxes aren't meant to be speed record holders, But the massive gear reduction contributes to the noise as well.
My first modification was to open the gearbox, clean the gears and inspect for any flash. seeing none, I then tried shimming the bull gear so it wouldn't move side-to-side in the box. I tried to find a thin washer at a couple fastener dealers but I couldn't find one thin enough. Finally I made one out of .015" styrene. It's inside diameter was 21/64" and I just made the outside diameter small enough not to interfere with the gearing. I'm not sure if using an even smaller washer on both sides of the bull gear will help. Keep in mind that this is an experiment. When I reassembled the gearbox back into the engine I discouvered that the motor wouldn't turn due to four lugs that hold it in alignment in the frame. The spacer that I had made squeezed the bullgear in the gearbox so you can do either one of two things, 1) make your gear spacer out of thiner material, or 2) file two of the lugs. I chose the later and now the gearbox spins freely. Upon reassembly of the engine I used my demel tool with a brass wire brush to clean both the wheels and the brass pickup wipers. Speaking of those I'me thinking of eliminating them and hard-wireing the trucks to the motor.
When I ran the engine with the spacer in the noise had diminished a little but I still think more can be done.
My next step it to try to isolate the motor from the frame, this will involve cutting off the two large shoulders on the cast frame and milling down the motor area, hopefully adding a rubber motor mount and seeing what will happen. I may keep my eyes open for a small can motor as well, as long as I can get one cheap.
I'll attach photos as I get them and try to keep my progress updated. As I said this is mostly experimenting, seeing what if anything will work to make the little fellow's noise level more mangable. If anyone has any suggestions I'm all ears (so to speak!)
While the design to strong, and the engine will pull like a mack truck, the noise that comes from it is considerable probably due to a few things:
1) the bull gear sits quite lose in the gearbox, allowing it to move back and forth and 'rattle' in the box.
2) the open frame motor is mounted (screwed) directly onto the frame, trasmiting all the motor noise to it.
3) the fact that the motor has to turn at high speeds for the engine to get up to speed. Granted climaxes aren't meant to be speed record holders, But the massive gear reduction contributes to the noise as well.
My first modification was to open the gearbox, clean the gears and inspect for any flash. seeing none, I then tried shimming the bull gear so it wouldn't move side-to-side in the box. I tried to find a thin washer at a couple fastener dealers but I couldn't find one thin enough. Finally I made one out of .015" styrene. It's inside diameter was 21/64" and I just made the outside diameter small enough not to interfere with the gearing. I'm not sure if using an even smaller washer on both sides of the bull gear will help. Keep in mind that this is an experiment. When I reassembled the gearbox back into the engine I discouvered that the motor wouldn't turn due to four lugs that hold it in alignment in the frame. The spacer that I had made squeezed the bullgear in the gearbox so you can do either one of two things, 1) make your gear spacer out of thiner material, or 2) file two of the lugs. I chose the later and now the gearbox spins freely. Upon reassembly of the engine I used my demel tool with a brass wire brush to clean both the wheels and the brass pickup wipers. Speaking of those I'me thinking of eliminating them and hard-wireing the trucks to the motor.
When I ran the engine with the spacer in the noise had diminished a little but I still think more can be done.
My next step it to try to isolate the motor from the frame, this will involve cutting off the two large shoulders on the cast frame and milling down the motor area, hopefully adding a rubber motor mount and seeing what will happen. I may keep my eyes open for a small can motor as well, as long as I can get one cheap.
I'll attach photos as I get them and try to keep my progress updated. As I said this is mostly experimenting, seeing what if anything will work to make the little fellow's noise level more mangable. If anyone has any suggestions I'm all ears (so to speak!)
