New GUN DRILL

[Cat Whisperer]

Got a brand new gun drill today (ebay $10 + $11 shipping).

I always wanted a good lubricant-through-the-bit drill.

This one's 1.18" in diameter.

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Did I mention that it's 32" + long?

[GGaskill]

You know that the feed per revolution for one of those is .0005" or less?

And the oil operating pressure is 1000 psi?

And rpm is pretty high also.

And you need to bore a hole for it to start in.

[Cat Whisperer]

Didn't know any of that.  I just figured that I'd be able to get $21 worth of use from it.  I appreciate the info.  It is very likely, because it leaves only 6" of space on my 38" lathe, that I will severly modify it.  Probalby cut it to half the length (that suits the scale of stuff that I build) and make multiple heads for it - spade drills and boring heads.  It has a 1" shank which fits into my home-made boring bar holder well.

[Soot Sucker]

You got a great deal deal Cat...

There certainly are some great deals to be had on eBay. Sometimes you just have to do some seaching and hunting.

You did real good!


S.S.

[GGaskill]

The cutting oil is used to force the chips out of the hole, so the chips need to be very small (hence the low infeed rate) and the oil pressure high.  If the chips stick in the bore, the drill will likely twist off.  :-(  So don't skimp on the cutting oil pressure.

I would try to keep the drill at its original length and make a holder that allows me to choke up on the drill (hold it in the middle instead of the end.)

[Cat Whisperer]

The cutting oil is used to force the chips out of the hole, so the chips need to be very small (hence the low infeed rate) and the oil pressure high.  If the chips stick in the bore, the drill will likely twist off.  :-(  So don't skimp on the cutting oil pressure.

I would try to keep the drill at its original length and make a holder that allows me to choke up on the drill (hold it in the middle instead of the end.)

That is one option that I've been thinking about - as I have a bunch of 1144SP in 1.75" diameter (short lengths) - I may well make a collar that will slide on it, secured where I want it, and will fit one of my boring bar holders.

The other option is to make a changable head on it for spade drill bits and boring bar cutters.

In any event it will most likely end up being driven by a need of a project.

[Cat Whisperer]

You got a great deal deal Cat...

There certainly are some great deals to be had on eBay. Sometimes you just have to do some seaching and hunting.

You did real good!

S.S.

Thanks S.S. - I've been watching the tooling seciton in general from about 10minutes to an hour before closings.  That way I can pick off an item with NO other bids on it and get it for what I want to pay.  Takes about 45minutes three or four evenings a week.