Mabuchi Gearbox Assembly

[Boco Gear]

My team and I made a decision that we were going to use the Mabuchi motor with the plastic gearbox on our bot but we are lost on how to assemble them to hold a shaft. Could someone help us with this?

Thank you in advance,
Brad

[vivek16]

Do you have Inventor?

I made a coupler to go to a 1/2 inch shaft a while ago. I could send you the part.

It was essentially a cylinder that had screws in the slots in the plastic of the output.

-Vivek

[Boco Gear]

Okay we found a coupling that will work but now the only problem is how do we mount it now to our bot we have brainstormed it and so far we have nothing.

Any Suuggestions are welcomed

[Skifanatic]

So how exactly do you mount a mabuchi 545 to a kit fisher price plastic gear transmission? We can't figure out how to do it because of the difference in the shaft sizes of the motors.

[vivek16]

Since the bodies of the 545 and the fp are the same, you can use the same mounting pattern. For the pinion, you will have to order another 32 dp, 19 tooth gear to press onto the 545 that has a smaller bore.

-Vivek

EDIT: neither martinsprocket, mcmaster or sdp-si have 19 tooth, 32 dp gears.

[Tristan Lall]

Originally Posted by vivek16

Since the bodies of the 545 and the fp are the same, you can use the same mounting pattern. For the pinion, you will have to order another 32 dp, 19 tooth gear to press onto the 545 that has a smaller bore.

-Vivek

EDIT: neither mcmaster or sdp-si has 19 tooth, 32 dp gears. I'll keep looking but I'm not sure what to tell you.

Maybe SDP/SI would have a 0.8 module, 20° pressure angle gear with a 3 mm bore.... (32 pitch is a close approximation, but not really the right size.) The gears you find there might be plastic, though.

The current F-Ps (as in, the ones in the kit in 2009) came with 16-tooth pinions, not 19.

[vivek16]

Actually, the shaft diameters on the 545 and the fischer price should be the same....

You should just be able to remove the pinion from the fp and press it onto the 545. May I ask why you are using the 545's instead of the fischer prices? They will work better. This is under the assumption that the FPs are not already spoken for elsewhere.

thanks, Vivek

[Skifanatic]

Well the shafts are different lengths so will a fisher price gear work on a mabuchi with the different shaft length?

[vivek16]

I'm not sure if it will fit at all without altering the gearbox because of the length. The shaft _should_ fit the gear though, they're the same diameter.

I'll let someone with a bit more experience with pressing gears onto shafts respond.

-vivek

[Tristan Lall]

I haven't tried switching the F-P gear to the BaneBots RS-545 motor, but I'd advise against it. The shaft on the 545 is much shorter, and not textured like the one on the F-P. (Then again, the motors aren't that expensive, if you've got spares. You could try it and report on your success.)

Also, the Fisher-Price 00968-9015 from this year is made by Johnson, not Mabuchi. Mabuchi makes the small RS-385 motor in the kit this year.

[vivek16]

The 545 shaft is significantly shorter, it also does not have the splines of the FP. I haven't tried to get a gear on there. I imagine a pressfit will be harder with the smaller, knurlless shaft. Personally, I would leave the FP's in and just use them.

Boco gear: The fischer price gearbox has bolts around the perimeter, just use longer bolts (make sure you don't risk the gearbox coming apart because of this).