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Mechanics and Construction => Mechanics and Construction => Topic started by: Firebot on April 14, 2011, 06:51:26 PM

Title: Class Project: Need help trying to power wheels with Drill DC Motor
Post by: Firebot on April 14, 2011, 06:51:26 PM
For one of my classes we need to build a robot that can put out fires. My design involves using DC motors striped out of a variable speed drill to move wheels to power tracks. I have no clue how I can convert the high speed of the motor in to a lower speed with high torque to power one wheel at a time or is it even possible to use one motor to power two wheels on each side instead of 2 motors per side.
Thanks
Title: Re: Class Project: Need help trying to power wheels with Drill DC Motor
Post by: rbtying on April 14, 2011, 08:34:09 PM
You would use gears.  Or, in this case, try a sprocket and chain (you can run the chain around both wheel axis as well as the sprocket, and it's more forgiving if you don't machine to exactly the right size.)
Title: Re: Class Project: Need help trying to power wheels with Drill DC Motor
Post by: Firebot on April 14, 2011, 08:47:59 PM
What kind of gearing would I use? Would a worm gear be best you think?
Title: Re: Class Project: Need help trying to power wheels with Drill DC Motor
Post by: garrettg84 on April 15, 2011, 06:48:58 AM
Worm gears are great for gear reduction, however they aren't very efficient due to friction. One other pitfall or perk depending on your requirements - once you stop giving your drive shaft power, your axle/tires are LOCKED up. It creates for some jerky movements, but it is nice to have such a drive system if the bot will ever need to 'park' on an incline or decline. This jerkiness can be almost eliminated but ramping up and ramping down power to your motor. Smoothing it out will require a little more coding on your half though.

If I were presented with this issue, I would find the smallest bike sprocket I could find and a much larger sprocket and use a bike chain drive. I'm not sure if that is overkill for your project though or what your monetary restrictions are.

good luck!
Title: Re: Class Project: Need help trying to power wheels with Drill DC Motor
Post by: waltr on April 15, 2011, 07:37:50 AM
What happened to the gear reducer that was in the drill motor?
Title: Re: Class Project: Need help trying to power wheels with Drill DC Motor
Post by: garrettg84 on April 15, 2011, 07:40:18 AM
What happened to the gear reducer that was in the drill motor?

Excellent question. I had originally thought the same thing, but then assumed that was included in the equation and still moving too fast or not providing enough torque.
Title: Re: Class Project: Need help trying to power wheels with Drill DC Motor
Post by: omkar on July 03, 2011, 08:29:25 PM
Check these out ... i did exactly this...
http://www.instructables.com/id/Mad-Dog-Robot/step5/Hack-Drill-Motors/ (http://www.instructables.com/id/Mad-Dog-Robot/step5/Hack-Drill-Motors/)
http://www.wa4dsy.net/robot/drill-motor-hack (http://www.wa4dsy.net/robot/drill-motor-hack)