My question is: Has anyone ever seen an attachment for a cordless drill that replaces your wrench in a knock-out set (2" and smaller holes). My boss said he saw one several years ago but has never been able to find one since. It seems like it would be a pretty slick device. Thanks!

You just need the right (7/16?) square drive socket and the adapter.

I am not sure a cordless drill would have the mojo to drive a slugbuster set, maybe a cordless impact gun?

I tried this once with my Panasonic impact drive [1/2" drive] and 1" socket.
It worked in so far as getting the hole punched but it also shook the bearing loose from the stud.
I wouldn't do it again. It's rather fun to use the power of one's arm to punch a 2" hole in sheet metal. If you are worried about production speed, have your employer provide you with the hydraulic version.
~Peter

Cut neat holes, but sound like the Green Line of the T coming into Park Street Station. (For those who don't know what that sounds like, imagine a loose fan belt at 150db!)

These are by Greenlee, but I have found another set simular and cheaper by another company. (Forget the name.) And are made better, and have a spring that helps keep you from crashing the carbide tips as the pilot goes though. I have determined that the bits definately last longer due to this improvement. The Greellee version will last through about 500 holes if alot of care is taken not to crash the bit. The other ones with the spring are easier to take care of, and are at about seven hundred holes, and counting.

[This message has been edited by e57 (edited 10-23-2005).]

thanks for the replies - I think the attachment had some sort of speed/gear reducer in it so you could use the speed of the driver to compensate for the torque needed to drive the knockout - otherwise you couldn't really control what you were doing too well

There used to be a tool called a Cobra that did just that--allowed a cordless drill to run a KO punch.

I googled it, nothing. Been almost 20 years since I've seen one.

Cliff

"I am not sure a cordless drill would have the mojo to drive a slugbuster set, maybe a cordless impact gun?"
I bet my 24v DeWalt has enough torque on low-speed.

E57, I have some of those Greenlee carbide holesaws and love them, however I have some that were used by idiots and the teeth got broken. So I have tried to find someone who could replace the broken tips, braze on new ones like you do a carbide saw blade, but have had no luck.
My question then is this: Does anyone know a place I can send them to be fixed? If so how much per tip? I understand the problem that most shops have is that this is a circular configuration and most people who replace the tips on saw blades do it in a straight line. Can anyone help?

WhiteRook, I wish I knew.... I have a dozen or so of them that I let the idiots use. (One of them was nearly tooth-less, and that should have been a sign, but I missed it. Bit came bake with fewer teeth than the guy had. )

Either way, the ones I have got now are lasting much longer by the simple addition of a 1/4" spring. The pilot goes through, and then you have to give it some light pressure on the spring to engage the carbide hole-saw portion.

At >$50 each they are a hard thing to spend money on, but when popping out >300 holes {FAST} in a set of panels, gutters and cans, they are money well spent. And just buy one for the job with the material, and figure if it lasts through that, its a bonus.

The only thing I know thats faster is a C-clamp for hole punches with an electric pump, and you really can only use them on everything but the back of a can or panel.

I have a Greenlee bi-metal set that I've used a lot, and never chipped a tooth. My "secret"? Using cutting oil.

Sure, it smokes, smells, and is messy, but the teeth are still sharp as new.

"There used to be a tool called a Cobra that did just that--allowed a cordless drill to run a KO punch."
Look on pages 18/19 here: http://edev.colorassociates.com/greenlee/holemaking.pdf

For hole cutters, how about the Greenlee Ultra Cutters, on page 51 of http://edev.colorassociates.com/greenlee/holemaking.pdf ?

(Edited to add: I didn't realized until after I posted that I'm pointing to the same document as Larry Fine just referenced. I guess the WWW isn't really that big of a world out there!)

[This message has been edited by SolarPowered (edited 10-24-2005).]