Bachmann 0-6-0


A

Andy120

New Member
Hi all
Has anyone considered re-motoring/modification to this little beasty to shorten the overhang and get it looking more like the short real thing?

Andy
 
Would a little 4 x 8mm 5 volt be suitable or underpowered? Im thinking relocate the motor to the other side of the worm gear allowing the forward edge of the firebox to be moved forward to between the 2nd & 3rd drivers. If i can work an additional reduction gear in, pulling power may not suffer since high speed isn't really an issue.
 
I can't comment on the required prototypical model changes, but reduction gearing should be unnecessary! Electric motors generate full torque at 0RPM, so really the only pulling power limitation is traction.
 
Well the little motor i was thinking of doesnt have a hope in moving it. back to the drawing board.
 
TrinityJayOne said:
I can't comment on the required prototypical model changes, but reduction gearing should be unnecessary! Electric motors generate full torque at 0RPM, so really the only pulling power limitation is traction.
Click to expand...

That doesn't make complete sense to me. Surely if you reduce the gearing in half one unit of torque only has to move the wheels half as far therefore it can do it twice as easily. admittedly you cant take advantage of the lower gearing unless you increase the weight on the wheels to give more traction.
 
The torque of the motor will be directly related to the volts (number of volts = the force applied to turn the motor shaft). Your trouble is your 5V motor, not enough volts. TrinityJayOne is correct though in saying that electric motors provide maximum torque even when not rotating because the "force" (volts and current) are generated from outside the motor, not internally such as in an internal combustion engine like we use in our cars.
 
Hi Andy,

I can give you a little bit of DC Motor theory.

Torque is inversely proportional to the speed of the output shaft.

DC motors have maximum torque at zero RPMs and it decreases as RPMs rise.

In other words it is a tradeoff between how much torque a motor can provide and how fast the output shaft rotates.

If your gearing slows down the output shaft you will have more torque.

All DC motors are rated for power output. If you use a motor that is rated too low the amperage will rise and it will reach saturation. At saturation Torque falls of linearly with the amperage above saturation. Heat will build up and thermal runaway will begin and the motor will fail.

You need a smaller motor that has a similar power output rating. That maybe difficult to find, because as you know with most electric motors, bigger is stronger because current needs a conductor of sufficient size to prevent heat from building up.

If and when you find that motor then you can determine what gearing you will need.

I don't have any experience with changing motors other then to replace them with the same motor. I am a mechanic not an engineer.

I bet if you keep asking somebody will have done this and be able to help you.

I wish you well.

Louis

Andy120 said:
Hi all
Has anyone considered re-motoring/modification to this little beasty to shorten the overhang and get it looking more like the short real thing?

Andy
Click to expand...
 
Thanks for the info guys. I have found 6x10 and 6x12mm motors, both need voltage dropping resistors for there rated 6v max. It doesnt help that decoders apparently pulse full voltage instead of actually varying the voltage like aircraft ESC's. I hope to increase weight by casting a new shell in a lead based alloy, which also aim to act as a heat sink. It will have to be insulated by plastic somehow. I will test the current gearing then try and determine what to do from there.
Andy
 
Here is where this idea has progressed to. I have the 6 x 10 & 12 motors, which will turn the wheels ok but could really do with further gear reduction. Finding suitable gears and placement is the next issue. An idea to series wire two motors to get higher torque and use the full 12v was squashed by the motor supplier on grounds that the motors aren't likely to like that.
Andy
 
I don't think that's a planetary. Most likely a parallel helical. Unless I missed something in the data. Nice for switchers or narrow gauge engines like shays. A little noiser than I like though!
 
Well ive got the gearbox but the motor which comes with it is only 3 volt. So now im looking at how to adapt the gearbox to the 6 volt motor. Every dimension is different!
Andy
 
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