Connecting a 48 pitch stepper motor gear to a tuning knob

[UR_Correct]

Hello all!

I am usually lurking and posting around the EE side of physics forums, but I have a project that deals with a little bit of mechanical stuff (please move this thread if I'm in the wrong place), and the mechanical aspect of engineering certainly isn't my forte.

To be as superficial as possible, I bought a small stepper motor that has a 48 pitch gear attached to it. Here is a link to it:

http://www.adafruit.com/index.php?main_page=product_info&products_id=168

What I need is a sort of conveyor belt type of thing that will mesh will with this gear. I've been looking up "48 pitch belts" or "48 teeth/inch belts" on google to no avail.

I essentially need this to turn a knob that sort of looks like this (I want to turn the 3-clover looking thing off to the side of the gears in this picture):

http://www.musiciansheaven.net/pics/142C1.jpg

In fact, it looks just like that. Because the gears on those tuning knobs are of a different type and most likely different pitch, I was thinking of buying a higher diameter 48 pitch gear and try to jimmy rig it (i.e., super glue the sh*t out of it) to the large 3-clover looking knob.

This is apart of a project for school, and the prof really only cares about the electrical part (which I have working beautifully), so I don't need this mechanical stuff to be too fancy. I just need the knob to turn with the motor. It's the last phase of my project, and I'm running out of ideas.

So, do these conveyor belt things exist? If so, how are they classified? Perhaps this isn't the best way to go about it? Any better ideas to turn the knob with this motor?

Thanks in advanced for any help.

-Mike

 

[AlephZero]

Look inside an inkjet printer or a scanner and you will find stepper motors driving toothed belts. That may point you in the right direction for buying parts, or you might find an old printer that you can cannibalize.

 

[Unrest]

What I need is a sort of conveyor belt type of thing that will mesh will with this gear. I've been looking up "48 pitch belts" or "48 teeth/inch belts" on google to no avail.

That gear is probably meant to mesh with another gear and I doubt you'll even be able to put a rubber belt on it even if you could find one.

One way would be a string instead of a belt. You can use a couple of turns around a rubber pulley to stop it slipping. Or, if the range of rotation is limited, tie the string to the pulley as well.

But I think the most robust and possibly easiest way is to make a custom coupling to connect the motor directly to the cut-off knob. Just get a short steel rod and drill a hole in each end for the two shafts. Then lock it to the shafts with a pin through a cross-hole.