which motor can we use for the shooter?

our team 1946# want to use a motor for the shooter but we can’t use CIM becuase we are using for 4 motors

You could use the Fisher Price motors, but you probably need to make a gearbox to reduce the speed, but not reduce it as much as the black plastic gearbox does.

We made a gearbox for that motor using a gear out of the black plastic gearbox. It has 4.5:1 reduction. The plastic gear has a hex shaped hole in it, so you can use a hex rod to make a shaft to drive the shooter roller. It might be difficult to make the holes in the correct location, but you might want to give it a try and see if you can do it. This gear reduction should work good with a shooter wheel that is about 5 inches diameter.


You might even use two Fisher Price motors. You will have about the same power as one CIM. Copy Squirrel’s gearbox, but use two motors to drive the same gear.

That’s a great suggestion.

I would also suggest the Fisher Price (Johnson Electric) motors. They’re 1/3 horsepower a piece (2/3 the power of the CIM, which is 1/2 HP) and runs at 15,600 RPM. Shooter wheels at normal diameter seem to work pretty well direct-driven from CIMs (5,000 RPM), so gearing the FP’s down by a factor of 4 or 5 should probably be good (because of the less torque of the motor compared to the CIM) for about 3-4 K rpm. If you can’t make a gearbox, Banebots makes some good ones that fit well with that kind of reduction range, and there’s also the planetary transmission from AndyMark (3.67:1). With whatever gearbox you use, if it’s low reduction, make sure you don’t stall the motors, because those FP’s have a lot of magic smoke in them, and are quick to release it. When you have a third of a horsepower in such a small motors, there’s a trade off in the pounding it can take. They can burn up without ever tripping a breaker.

Alternatively, if you’re using the FP motors already, you could use the Banebots motors. They’re less powerful (about 1/4 HP), but run faster (17,500 RPM) and don’t burn up AS EASILY (that’s not to say they don’t burn up). Banebots sells gearboxes for these with the motors only, because the motors themselves are only about $5.

One reason I suggested using the gear from the FP gearbox is that the team who asked, is in Israel, and might not be able to recieve any parts from the US in time to put them on their robot.