Klein Unibit

[surfsup]

What a POS. I drilled out 5 noval socket holes last night in 0.075 aluminum and its already dull. At this rate, I'm going to chew through one of these for each amp chassis.

I am considering getting a few solid carbide or aluminum specific HS tools since I am in the industry. Its worth the $75 a bit to rip through it like butter with no coolant necessary.

Do the punches work well/easily?

[Gibsonman63]

Greenlee knockouts work very nicely. I used to build control panels and we used them regularly on all types of metal boxes to cut holes for pushbuttons, lights and conduit entry. Stainless Steel can be a little tough, but you probably won't be making to many amplifier chassis out of it.

[Kazooman]

I haven't personally used any chassis punches but I believe that they would do a great job for you on aluminum.

Unibits are great, but they do have one problem. By their very design they don't have a very efficient way to clear the chips of metal as you drill. You often end up with a buildup of metal on the cutting edge. This results in a lot of friction and resulting overheating (and hence dulling) of the bit.

I usually only have a few holes to drill and when I check the bit when I am done I often have to use an awl to pick some metal off the bit. It is stuck on very well!

I suggest stopping your drill press between holes long enough to inspect the bit for a buildup of aluminum. Clean it up before drilling the next hole. A PITA for sure, but it's probably necessary with a unibit.

[surfsup]

Yea, there is a lot of "gumming" going on. No chip breaking whatsoever. The cutting angle is all wrong on these things. I guess that's what you get for $15 these days. Cheap junk.

Maybe its because I'm used to 500-1000 inches per minute even with single tooth cutters. Here's some aluminum cutting:

http://hardmilling.com/sitebuilderconte ... 00-ipm.zip

I slowed it down (hand drill) and peeled off the long spiral chips (not the type of chips I want to see, or should I say "chip"...LOL) and pressed on. I got 'em done but what a PITA. My aluminum pedal enclosures were fine though with the same unibit.

What size do you guys drill for the PT/OT wire leads? Ace has some grommets I think they were 3/8" inner D.

[Kazooman]

Very impressive video! I imagine that they keep the cutting angle low on the unibits so that they don't grab the workpiece. Anyone who has tried to hand hold an aluminum stompbox enclosure while drilling a hole with a decent diameter standard twist drill knows what happens

[XgamerGt03]

Are you lubricating the bits? Any time I use unibits I always spray them down with WD-40 before I start, and every few holes I respray them. It works out pretty well for me, but now I have access to a hole punch for noval sockets so i'm going to start using those. If I had the money I would buy an entire set so that I didn't have to use many bits at all.

[Kregg]

I am considering getting a few solid carbide

I thought that carbide was a bad choice for aluminum bits, because they get gunked up. I was once told to use bright steel or cobalt for drilling aluminum.

[rp]

$15 for a Klein unibit? Aren't these things like $40 on up? Unibits on a drill press are ok, kind of scary with a hand drill.

I bought a set of Greenlee punches, the amp sizes 1/2, 3/4, 1 1/8, 1 1/4, long ago it's really worth it, you'll use the hell out of them and they last forever if you treat them right and stick mostly to aluminum. They're expensive but you really need just 3/4 & 1 1/8 to start and the later =s the price of the unibit.

[Ken Moon]

The Irwin unibits are much better quality. The one you got sounds like the ones from Harbor Freight - basically useless.

I've used the same size 5 Irwin unibit for about 30 amps now, and it seems to work as good as new (I use .090 aluminum chassis).

I use kerosene as a cutting fluid (just keep spraying it out of a little spray bottle), and a big ole' 1/2" chuck hand drill I got from Harbor Freight for about $30 on sale, which has a top speed of 500rpm, perfect for this work.

Here's the one I use for octal sockets:

http://www.amazon.com/Irwin-10235-Unibi ... B0009XJ31A

[M Fowler]

What I have been using the same cheap three piece set from Harbor Freight for three years and have drilled a lot of amp chassis.

Mark

[surfsup]

I thought that carbide was a bad choice for aluminum bits, because they get gunked up. I was once told to use bright steel or cobalt for drilling aluminum.

Agree solid carbide is not "as" good as an aluminum tool, but I can use em in steel without worry where I wouldn't the other way around.

Maybe I'll get the punch but the drillpress is at the P's house, its not mine...

[Gaz]

1+ on the 'real' Irwin bits, well worth it for the 3-piece set. Also, Greenlee makes really nice step bits as well - probably better quality than Irwin, in fact. Any good stepbit will be dual-fluted, stay sharp when used with cutting oil, and leave less burrs.

[rp]

1+ on the 'real' Irwin bits, well worth it for the 3-piece set. Also, Greenlee makes really nice step bits as well - probably better quality than Irwin, in fact.

Klein makes very good tools. They've been adding many more things all MIC and maybe the step bits are MIC but their good metals tools still are USA. Check the bit, if it's USA it was $40 not $15 and first rate.