Drill Gearboxes

[archiver]

Posted by Dan.

Student on team #10, BSM, from Benilde-St. Margaret's and Banner Engineering.

Posted on 2/13/2000 3:43 PM MST



Two questions:
1. What exactly is the purpose of those 'anti-reverse' pins in the drill gearboxes (besides breaking)?
2. Does anyone know if these are common in other cordless drill gearboxes, specifically in DeWalt brand drills?
Thanks for your help, :-Dan

[archiver]

Posted by Dodd Stacy.

Engineer on team #95, Lebanon Robotics Team, from Lebanon High School and CRREL/CREARE.

Posted on 2/13/2000 4:43 PM MST


In Reply to: Drill Gearboxes posted by Dan on 2/13/2000 3:43 PM MST:



: Two questions:
: 1. What exactly is the purpose of those 'anti-reverse' pins in the drill gearboxes (besides breaking)?
: 2. Does anyone know if these are common in other cordless drill gearboxes, specifically in DeWalt brand drills?
: Thanks for your help, :-Dan

Dan,

I think the basic reason is so that you can operate the 'keyless chuck' by hand (in either direction). When you attempt to overdrive the drill/gearbox (in either direction) to tighten or loosen the chuck, the 'anti-reverse pins' lock up the gearbox to give you something to torque against. I assume all drills (cordless or not) that use a keyless chuck incorporate anti-reverse pins, regardless of brand.

When you throttle down on a traveling robot (forward or backward), the momentum of the robot 'overdrives' the motor, causing the pins to lock up and pitting the entire kinetic energy of the 130 lb robot against the torsional strength of a bunch of plastic gears and housing pieces trying to resist. The only thing that prevents the entire thing from shattering on the first try is that the wheels slip on the carpet and limit the peak torque.

TAKE THE PINS OUT.

Dodd