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How do I incorporate a hobby-style motor into a project, physically. How do I mount it and connect a wheel to it? (Assume that I have a working H-bridge or even switches, and am not concerned about how to use the motor electrically, just physically.)

I've purchased small, hobby style motors at various times. Typically, they run on 1.5 V to 12 V, and many of them have no built-in gearing (and thus spin really fast with very low torque). How do I connect a wheel to it, or a gear or pully?

Next, most motors of this sort are round. Round! If it was flat on one side, I could glue it down. It looks like they are designed to be screwed into something at the front or back, but I don't know how I'd make a surface to mate to it nor make marks to drill holes through it precisely enough.

What have you found works for when you want to make an electronics project move around on its own?

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I would suggest you look at some shapelock. Shapelock.com

You can mold any type of mount you want with this. You could also buy gearboxes that are designed to mount on these hobby motors. But as cheap as they are you may want to consider buying some with the gearbox already attached.

Most hobby supply stores have assortments of wheels, sprockets, gears and pulleys for these or you can find them on ebay.

Good luck and let us know what you build.

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  • \$\begingroup\$ Now that is interesting. I happen to have some Shapelock, and I really haven't done much with it. (At the moment, I'm just trying to build a simple robot, as a practice before trying to build a rather larger robot. If I actually get anywhere with this, and remember, I'd be happy to post some details.) \$\endgroup\$ – Clinton Blackmore Feb 4 '10 at 17:37
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    \$\begingroup\$ Hmm. Thanks for the link to shapelock (sounds neat!), but I would not recommend using it for any motor that is going to heat up. Motors can easily exceed 150F = 65 C. \$\endgroup\$ – Jason S Feb 6 '10 at 14:14
  • \$\begingroup\$ Jason you are correct that if the motor heats up above 150 this is not a good solution, however for a small robot I don't think his hobby motor will get that hot but I could be wrong, I find quite often I am :) \$\endgroup\$ – Mark B Feb 6 '10 at 20:01
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    \$\begingroup\$ Shapelock is PCL, isn't it? \$\endgroup\$ – XTL Jul 22 '10 at 19:47
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get some cardboard or even decent paper & push the axle through it without enlarging the hole. You may need to place masking tape to reinforce the hole once you've made it. The idea here is to maintain the accuracy of the centre hole. After this get a pencil & rub it on the paper so as to make a kind of 'picture' of the surface end of the motor, making sure you can see the mounting holes in the picture. You can then use this paper as a template to make a right-angle mounting bracket for it. careful not to use too long a mounting screws into the end of the motor as they may foul the commutator brushes or the armature. I find a good source of tiny little self-tappers in cheap import shops, not available separately but in carefully chosen throw-away cheap plastic toys etc. Just choose yourself a toy with lotsa little screws!

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Mounting motors can be a pain. One ugly, but workable trick in some situations is using hose clamps.

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Get one of the Tamiya Double Gearbox kits. They are quite cheap, and come with two motors and two gearboxes, with shafts for attaching wheels. I've got a couple of them, but haven't got round to assembling them. When it's put together all you need do is build it into a little cart, add a couple of H-bridge drivers and start programming.

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  • \$\begingroup\$ What are you guys meaning by H-bridge drivers? Is it not ok to just plug the leads of the motor up to a potentiometer and battery? \$\endgroup\$ – LoveMeSomeCode Jan 27 '11 at 22:02
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    \$\begingroup\$ @LoveMeSomeCode : you'll get a better response if you post that as a fresh new question, rather than a comment, if Wikipedia: H bridge doesn't already answer your question. \$\endgroup\$ – davidcary Nov 13 '11 at 12:58
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If nothing else you can buy motors from Roombas rather cheap here: http://www.protechrobotics.com/ or even cheaper here at roombarecycle The Roomba motors either have gearheads on them or a head to use a rubber pulley. Most mechanical parts can also be found there.

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An H-Bridge is a circuit that has 4 transistors (2 PNP and 2 NPN) that will control a single motor in 4 states (forward, reverse, coast, and braking). Can use bipolar transistors for low(hobby) power up to about 500ma or MOSFET transistors for more power. You can buy H-bridges preassembled but spendy. My 2004 copy of "Intermediate Robot Building" by David Cook has a good explanation in Chap 10 and 11 of H-bridges. Lots of H-bridge explanations on the net. chris-m

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    \$\begingroup\$ Is this ment to be an answer to one of the comments? The OP didnt ask for an H-Bridge explanation. \$\endgroup\$ – PetPaulsen Mar 27 '12 at 7:17
  • \$\begingroup\$ maybe its because this site is only electronic stuff not mechanics \$\endgroup\$ – skyler Apr 22 '13 at 16:28
  • \$\begingroup\$ "Assume that I have a working H-bridge". -1 \$\endgroup\$ – Federico Russo Sep 11 '13 at 12:46

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