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umm... my motor kinda looks like that except the stick that protudes is a bit longer.
The gear can stay on but the hole in the middle of the gear doesn't fit the stick well, so the gear can spin if you touch it.
Since the stick on the motor (sorry dunno what to call it) is supposed to spin when the electricity gets to it,
i thought it might be a problem...

yea that would be a problem
you could try three things
1.get a different gear
2.glue the gear that you have to the motor stick
3.get a different motor

robotman09 wrote:the stick on the motor (sorry dunno what to call it)

That "stick" is called the "shaft". Any play/wobble in the gear can cause problems. Besides the obvious probability of slipping on the shaft, it can cause the gears to bind and possibly wear extremely fast. The gear may even come off the shaft at the worst possible moment (Murphy's Law).

If the fit is pretty close, with no visible gap, you might be able to glue the gear on the shaft. If you use superglue (cyano-acrylate), be carefull it doesn't run up/down the shaft into the motor's bearing.

If there is a gap between the gear and the shaft. You will probably need to “shim” the shaft to make it large enough for a tight fit. Here are some ways I’ve tried (with varying success):

Wrap tape around the shaft to make it larger. Start by wrapping the tape around the shaft until it is bigger than the hole in the gear. Next cut off and remove short pieces of tape until you get the fit you want. It’s easier to get the gear on if the tape sticks out slightly beyond the end of the motor shaft. This makes the end tapered slightly.

Use an appropriate size brass tubing to shim up the shaft. Hobby stores stock brass tubing in various sizes that are a slip inside each other. You can use more than one size to add layers until the shaft is the necessary size for the hole in the gear.

I’ve used insulation stripped from electrical wires or plastic/rubber tubing. It may take a while to find a size that works and it’s possible you won’t find one.

Finally, I’ve not had much luck getting any method to work reliably, especially under heavier loads. In fact, many commercial methods for adapting gears to various sized motor shafts don’t work well.

At any rate, as the old, old saying goes: Use that lump on your shoulders for something other than a hat rack! Keep thinking, trying and you will succeed. It’s good to ask for ideas, but only you can make them work on your device.

thanks! I am much obliged.
i'll see what i can do...

I've played a bit with gears on motors, and this is what I did, with success (I never actually put it into place, however, just to note).

First of all, I went to the hardware store to look for a bushing. However, the size I needed doesn't exist. If the size you need does exist, get it. I did find something, sorry I don't know the name, it was kinda like a threaded bushing, and a bit tapered. It fit very snugly into the gear, but the center hole wasn't big enough for the shaft to fit through. I used a drill to enlarge the center hole as straight as possible (it ended up being very slightly tilted). The threads carved a bit into the plastic gear, keeping it in place, and a bit of hot glue kept it on the shaft.

Whatever you do, be precise, and good luck!

starpug wrote:

49ers wrote:thanks
so do you think you can get one easy if you don't have one of those remote control cars???

You don't need a prefabricated chasis, you probably can't use one anyway because it's against the rules. You just need a couple of small pieces of wood or metal and some wheels and axles. Then you just have to ad a place to put batteries and a motor or two and a switch and you're good

getting a pre made chais against the rules??
????

There are no rules yet, so nobody can say. It was legal for EV.