What motors do you use to drive your robot?

[_GP_]

I'm curious to know what other teams use as their main drive motor?

Our drive trains group wanted to use the drill motors, are these appropriate for the drive train? I had assumed they would use the big CIM motors, but they were worried about having to gear tehm down alot.

Thanks for any help

[Chris Fultz]

Last year, team 234 used a drill and CIM geared together and then geared way down so that we were slow, but deadly powerful. We geared a transmission in as well, but we ended up not switching gears. This same setup can be geared higher to be faster, or whatever you want.

Hope this helps

[ShadowKnight]

drill motors work fine and our team is using them again this year. It's crzy easy to do the drill motors simply because the mouting is prefabricated and the gearbox is something that has already been built. They're less of a drain overall on resources to use. Problems with the drill motors can be heat, our motors had major problems with heat because we ran one forward, one in reverse and the drill motor is not designed to go in reverse for any long periods of time. In time, one of our motors literally cooked, the back melting into a big mess of plastic and wires and all that. Heatisnks have been used before the cool the motors as have fans, though that does some to cool the motors, heatsinking is better.


The problem however with the Atwoods (the CIMS you were talkign about) is that there were not designed to run for long periods of time according to one of our mentors. They lack a cooling system, fans or even vents, for that reason. So when you run them, all the heat builds up insides of the motor and you end up setting yourself up for major problems. The other issue of gearing down is a valid one because a gear box (and a good one at that) is needed so that the drive train will not kill it self when it tries to inch forward...they spin I think at like 5000rpms or something like that when you hook them up to a battery. So you WOULD have to gear down the atwoods...and if the gear box isn't build lacking completely of movement, gears start seperating and thus, start stripping. It can be very bad.

All in all...stick with the drill motors. They're convenient and lack a lot of the problems that the Atwoods have.

[MisterX]

Typically we have used the drill motors for the drive train (like every past year) but this year we are trying something different and going with the Chipuau (Indian Outlaw, half Cherokee and Tompawa, there a one of a kind) But yes I definetly agree with the gearing down part; right know we are having to decide between two gear boxes that we might use.

[Cory]

You might want to add Drills+CIM's.

As for your question, either one will prove to be fine. The Drills have a bit more power than the CIM's. They can be shifted using their transmission if you wish, and you already have the mounts and gearboxes if you dont want to make a chain and sprocket drive. People have voiced concerns with the integrity of the transmissions, but if you do it right, there wont be any problems. Also, the drills wont backdrive in their standard configuration, which may or may not be an advantage.

As to the CIM's, they are very easy to mount using the holes on the face. (10-24, I believe?) They still have a good amount of power, they don't overheat as often as the drills. They don't have an anti backdrive feature like the drills. They are also a bit heftier than the drills. One plus is that they spin at approximately the same speed forward and backward, unlike the drills, meaning that your robot wont drift to one side constantly.

Cory

[Atman]

We used the Atwoods last year with our two speed transmission and they seemed to work just fine. We are probably going to end up using them again. We had them geared just right and they gave us the power to push anyone we wanted around in low gear running at 4fps. Even in high gear we were able to push a lot of the competition around at 10fps. No problems with overheating. In years past we did use the drill motors and they were effective.

[Matt D]

In past years, we have gone with just the drills (2001, 2003). In 2002 we used the drills and the CIM's with a complex and heavy chain & sprockets transmission (We didn't have a machine shop).

Last year we just used the drills, shifted them with servos, and geared them down with chain. It worked well, although we had trouble overheating during the playoffs. We fixed that by cooling them with canned air (which is freezing cold).

It is much easier to go with just the drill motors.

[Jeff Waegelin]

We used the CIMs the past 2 years, but we'd used the drills the previous 4 years. This year, we're using the drills and F-Ps together.

[Paul Copioli]

We have used the drills and CIMs the last 2 years (actually, in 2002, we used the drills, CIMs, and Fisher-Price).

A little more information to help you out:

1. The drills this year (and last) are great for rookie teams due to the pre-fabricated gearboxes that come in the kit. The drills are also the most powerful motor by about 30% - 40%.

2. The CIMs are an excellent motor for driving because they are close to the same speed in forward and reverse and since they are a big motor, they dissipate heat a lot better than the drills.

The CIM motors are excellent for driving and we have never had a problem with overheating. We have never failed a CIM motor, but have burnt both the FP and the drill. The CIM motor is very robust.

3. I would only use the F-P if you are combining it with the drill or the CIM. I would not use it by itself.

-Paul

[Jay H 237]

Since our team has had success with the Bosch drill motors we keep using them year after year. We keep the transmission on them (with the pins removed) so we can have low and high range shifted by a small pneumatic cylinder. Our drive train has one mounted on each side and connected to the wheels with 35 chain. The motors are mounted opposite each other and one is connected to a jack shaft before the spocket to the chain so it will run the same direction of the other motor. This solves the problem of the robot "drifting" to one side when driving. They do get hot if they're driven long (like in a parade) but they don't get a chance to heat up during a normal 2 minute competition match.

[TheShadow]

Last year we had too many issues with the drill motors. This year I think we're going with the Chippewas

[Spikey]

We will use either the drills, or the CIMs. It all depends on what we use the other motors for *Wink*

[Smrtman5]

Last year was the only year (that i know of) where we used the CIM motors, and we did have a large and heavy (and poorly constructed) gearbox. This year were reverting to the tried and true drill motors.

[pras870]

Well the past 3 years we've used the drill motors (this year is no differerent). Last year though, we tried a dill/CIM combination which worked pretty well, although they added a lot of weight :/

[sanddrag]

Originally Posted by Cory

The Drills have a bit more power than the CIM's.

If my calculations are correct, the Chias have more torque at 40 Amps than the drills. But the drill does have a higher stall torque and is overall a more powerful motor.