Instructables

Hacking Drills- Cheap/Powerful Gearmotors for Robotic Applications

This Instructable will cover the process of how to modify a generic cordless drill for use in robotic applications by removing the chuck and disengaging the slip clutch. It will also cover mounting options for the motors.

Why use a drill motor instead of a purpose built gearbox/motor like a Banebots P60?

1. Cost. It's around $80 for a banebots gearbox/motor and about $30 or less for a cheap drill.
2. Drills are designed to be lightweight, durable and powerful. (isn't that we want in a motor?)
3. They are almost the same thing as a Banebots P60, but with more plastic. they have a similar final output speed*, and identical motors in most cases.
4. You get a battery and charger, which are always useful.

I use two of these in my top ranked combat robot Phoenix


* Banebots 26:1 gearbox with a 550 size motor outputs ~900rpm, which is about the same speed that most cheap drills spin at.
 
Remove these adsRemove these ads by Signing Up

Step 1: What You Will Need

Picture of What You Will Need
1. Cheap cordless drill such as the Harbor Freight 18v 900rpm drill but any single speed 500-900rpm drill with a 3/8" chuck will do.
2. V-Jaw Pliers
3. Snips
4. Cordless Drill (will not be disassembled)
5. 2 10-32 set screws and hex key for them
6. Philips and Flat Head Screw Drivers
7. 1/4" or larger hex key (it need to fit in the drill's chuck though)

Not Pictured
8. Steel pipe preferably about 2-3' long and 3/4" or smaller diameter
9. Table mounted vise
What about Speed Control? Can you hack the trigger controller or do you need something special?
AlexHrn (author)  Dream Dragon1 year ago
you could probably do trigger control with a servo or something else.

for pwm based esc's i have couple of recommendations...

for a dual channel esc,

=0 designs ragebridge http://e0designs.com/products/ragebridge/



for single channel esc's

holmes hobbies torquemaster brxl http://http://holmeshobbies.com/Holmes-Hobbies-TorqueMaster-BR-XL.html

or

botbitz's escheap85 http://www.botbitz.com/index.php?route=product/product&path=59&product_id=59
WOW! Those are expensive, not to mention American, and I'm not sure I'd know what to look for otherwise.

However, if you are using it for a robot, surely all you need is some kind of Transistor or Relay? The Processor would (Presumably?) deliver PWM signals at it's usual logic level and you'd just need to make that switch the higher power side (with apropriate isolation). Or am I missing something?
AlexHrn (author)  Dream Dragon1 year ago
i use rc airplane equipment

http://www.hobbyking.com/hobbyking/store/__28494__OrangeRx_T_SIX_2_4GHz_DSM2_6CH_Programmable_Transmitter_w_10_Model_Memory_Mode_2_.html

you could also something with  arduino to generate the pwm signal.

the esc's i posted before are ones i recommend for combat robots. if you are building a non combat robot you could get away with a 12a esc like a sabertooth 12

http://www.dimensionengineering.com/products/sabertooth2x12

but do not use them in a combat robot. they tend to fail in combat robots becasue of the shock forces involved.
Ahhh! Now I hadn't figured on the whole "Radio Controlled Demolition Fest" that is "Combat Robots". I can see why you'd need something much more robust for that.

I was thinking of a basic mobile robotic platform, just with a bit more oomph! Arduino, Picaxe, and just about any processor will be able to generate something resembling a PWM signal, it's just a matter of using that to switch the high power side.

Thanks for answering my questions though, thanks for posting the project in the first place, keep up the good work.

And Best of luck in the combat arena.