Metropoulos Forum

What do you guys use for the bigger holes like the power tube sockets?

I've seen a tool (bit) that's shaped like a cone. I think it allows for any size that you want?

That bit you're referring to is what they call a stepping bit, which should be used anytime you drill through metal to get minimal flash(the burrs you commonly get around holes drilled through metal).

For the bigger holes such as tube sockets, you're gonna wanna use a hole saw.

Jon

I posted a while back in the general topic page about having purchased a greenlee stepper. Great buy. Theyre hella expensive, like $60-$70, but they do a great job for any chassis hole you need. Youll need the 1-3/8 sized bit (the biggest and most expensive) to do all holes including power tube and filter cans. They probably do the cleanest job next to punching. Buying a reamer or file to clean up the flash is a good idea too.

you can get those on ebay for $30-$40 as well.

BTW - use your drills Low gear and for steel some 3in1 isnt a bad idea.

a punch set can be had from harbor freight for $20, and it works better than the step bit. the step bit will leave one side of the hole slightly smaller than the other which drives me nuts! but a step bit is much faster.
mike

for alluminum, you can buy regular wood spade bits. they work great if you keep the drill steady. and you can do about five chassis's before they are too dull. they only cost a few dollars and work better than the step bit.
mike

myker wrote:for alluminum, you can buy regular wood spade bits. they work great if you keep the drill steady. and you can do about five chassis's before they are too dull. they only cost a few dollars and work better than the step bit.
mike

I used them before the step bit and did not find that to be true. Both had close to the same amount of grit but the stepper Im using now is beter with a slow even drill.

Is this something like what your talking about mike

http://www.harborfreight.com/cpi/ctaf/D ... mber=91201

Is that all you need for it?

Ebay, ebay, ebay. I recently bought a step bit that will cut up to 1-3/8". Brand new, delivered in less than a week. Quality probably isn't as good as Greenlee, but mine works just fine. For the ultimate in ease and perfect holes, get yourself some knock-out punches. ALL OVER Ebay. I originally bought mine from Mouser but paid top dollar. I think they're worth it. I've a 1-1/4" and 3/4". They're about $30 each. I've since discovered a bunch on Ebay (usually used). Greenlee's are the most popular, but there are others that work great.

dan, thats exactly the model that i have. thats all you need. it takes longer than using the step bit, but makes a nicer hole. did i just say nicer hole?
mike

How do they work exactly? I have a general idea.

Say you were going to punchout a 1" hole. You would first mark it out, and drill a smaller hole in the
center of the 1" hole. This is for the drive bolt that will hold
the 1" die and punch. (Basicly a bolt with bearing on it)

After you drill the hole,you slide the 1" die
over the Drive Bolt (flat side towards the bearing), then slide it into the hole in the chassis, then thread the die on the other side until the teeth are hand tight against the chassis. Squirt a little oil to help cutting.

Then you tighten it with a wrench or drill to cut the hole.

Yes! Knock-out punches are by far the best way (short of milling) to make perfect holes. And definitely the easiest. I've used step bits, serrated hole cutters, abrasive hole cutters, etc. and none come close to the ease of punches. No shavings, no chattering and no bit walking. Found all over Ebay. Just search "chassis punch" or "Greenlee punch".