Sumpter250 EOY 2010 challenge

[Green_Elite_Cab]

Sumpter250
As Galen wrote before, i too see no need to place the motor in the tender. If the motor is in the tender you need to use a long drive shaft with two universal joints and with a telescoping member in the middle.

Galen wrote:
"You just might be able to get that dinky little motor in the boiler or firebox somehow. Is there a particular reason for putting it in the tender?"
That was tried, and is the reason why this project wasn't done a long time ago. I had intended on using a gear tower, so that the motor could sit on to of the drive gear box......it didn't work.
Leaving the boiler "empty", allows me to get the loco's weight balanced for better tractive effort.

Schraddel wrote:
" On the photo it seems to me there is a brass bushing over the Motor shaft. And it's outside diameter is equal as the diameter of the gearbox input shaft. "
The brass bushing was part of the above mentioned "gear tower modification". I may turn it down just a bit to accept a smaller universal fitting ( cup ).
the drive will be configured: [drive gear box shaft with cup...intermediate (through firebox/cab) shaft with ball, and cup in the cab area...connecting shaft with ball at both ends...and cup on the motor shaft.
The other consideration is that that intended motor, will not be strong enough to move the loco. The boiler area is not big enough to allow a larger motor, without removing all the backhead detail I've already built. There's room in the tender for a slightly larger motor if needed. ( I really didn't want to see "motor" inside the cab ).

Have you considered using Model Aircraft Neoprene fuel line? This may easily solve your drive problem. You only need to cut the fuel line the proper length between the Worm gear's shaft and the motor's shaft. It will pull apart easy enough if you have to, but when the motor turns on, It clinches down on the shaft, kinda like a Chinese Finger trap (you know the one, where you can't pull your fingers apart?). If the locomotive ever binds, the fuel line will twist off rather than let your motor burn out.

Its actually a very reliable technique, and i've used it to repair a couple P1K RDCs and an old Metroliner (pictured below), as well as tried it in an old Athearn locomotive. Again, its probably cheaper and easier than to try and make a solid drive shaft. it is flexible and will stretch and twist with the tender.