SparkFun Forums

[nhibou]

Hello,

I have a small DC motor from the sparkfun inventor's kit. I can make it work easily thanks to the instructions.

Though, the "stem" is very small and "slippery" ==> I'm not sure how to "use" it? For instance; how do I attache a gear to it? Should I glue it?

Or maybe it's only meant to vibrate ?


Thanks!

[nhibou]

Hi,

Hot glue doesn't work well...

Any idea how to use the small DC toys motors?


Thanks!

[leon_heller]

The gear needs to fit the shaft properly. It should be secured with a suitable screw.

[nhibou]

Hello,

It's a very small DC motor, there is no screw and I haven't any gears

note: i'm not talking about the servo

Thanks for your help!

[leon_heller]

You said that you wanted to attach a gear to it. You need to buy one with a screw, that fits the shaft.

[fll-freak]

Working with small motors is always a problem for the reason you just found. Trying to connect a mechanism to the shaft can be all but impossible for the hobbyist. In the manufacturing world, items are connected in several ways. They are pressed onto the shaft. The item has a slightly smaller diameter hole and they are pressed together. Another way (as Leon noted) is a small screw (set screw) in the item being attached. A "flat" is another way items are attached. The shaft has a small flat spot ground into it. This acts as a key for a plastic gear that has a D shaped hole.

For us mortals, finding a friend with a lathe is important. With the tool, you can make custom connectors. Without one, you can try small diameter surgical tubing. You can often find the right inside diameter brass tubing at a hobby store. These can be cut to size and crimped or glued into place.

[esklar81]

Other thoughts:

1. If you do find a gear, pulley, or coupling with a set screw, you may want to file a small flat onto the shaft against which to tighten the set screw. Otherwise, if you ask for much torque, the shaft is likely to spin inside the power transfer device you connected to it.
2. I've had moderate success in mounting small motors to some small plastic parts by drilling an undersized hole in the plastic, then soaking it in hot water for a few minutes before pressing in the shaft. Filing a flat on the shaft should help.
3. The datasheet for the motor shows the shaft as 1 mm in diameter. That should help in finding a suitable thing to which to connect it.

Have Fun,
Eric