Center Drill Holder

[Brian Rupnow]

I wanted to try out the tailstock lock that I just added to my lathe, and one of the things I've been meaning to build for a while now is a center drill holder. Every time I go to drill something in my lathe, I have to put a center drill into the tailstock chuck, tighten the chuck, drill the center hole, then remove the center drill and put in the appropriate sized drill. I wanted something with an MT2 taper that I can just pop into the tailstock to do my center drilling. I bought an MT2 blank, (they're only about $6) but it was just too short. I needed something that had a bit of reach to it---that would stick out past the tailstock at least as far as the tailstock chuck does, when mounted in the tailstock. I had a 3/4" diameter peice of "mystery metal" laying around, so I drilled a hole .22" all the way through it and reamed it 0.25" dia.to a depth of 1.05". (That way if my center drill ever breaks off, I can poke it out from the other end with a 3/16" rod.) I drilled and reamed a blind hole 1.25" deep in the MT2 blank. Both the holder and the MT2 blank were then drilled and tapped 1/4"-20 for a set screw. There was no tang on the tail end of the MT2 blank, and I wanted it to self eject from the tailstock when I cranked the handwheel all the way back, so I screwed a 3/8" bolt into the tapped hole in the back end of the blank (with a little 638 Loctite) and cut the head off. The tailstock lock works bloody marvelous, and I now have another peice of "Homemade" tooling.

 

[mklotz]

I did that too when I was starting out but I quickly discovered a problem. It took as long to retract the TS quill to eject the chuck as it took to mount and unmount the center drill.

After buying an Albrecht keyless chuck for my mill - one of the best investments I've ever made - I bought a knockoff of the Albrecht for the TS. Now changing from center drill to drill, etc. is a doodle - just grab the chuck, twist, insert center drill, and twist again. It takes longer to write it than to do it.

Keyless chucks are wonderful things. Their only drawback is that they don't work in reverse - they're strictly for clockwise turning.

 

[black85vette]

I like your solution for the missing tang. I need to do that to my live center.

 

[Brian Rupnow]

Mklotz--You may very well be right. I am still in "Time killing mode", and I did want to try out my tailstock lock. One thing about making things from scrap material---If it doesn't work, or I find I don't use it, I'm only out my time, which isn't worth very darn much these days!!!!! :'( :'( :'(

 

[black85vette]

Lets see:

1. A lathe = $700
2. Tooling = $800
3. Materials to "learn" on = $200
4. Brian's contributions to our hobby = invaluable

I wouldn't say your time is not worth very much.

 

[ozzie46]

Lets see:

1. A lathe = $700
2. Tooling = $800
3. Materials to "learn" on = $200
4. Brian's contributions to our hobby = invaluable

I wouldn't say your time is not worth very much.

Hear Hear Vette, I agree whole heartedly. Thm: Thm:

Ron

 

[Stan]

black85vette: Tailstocks are designed to hold centers (fixed or live) which never have a tang. They should eject the center without having to modify it.
Brian's MT stub comes with a threaded hole in the small end which may be too large for the ejection end to hit.

 

[doc1955]

Here is just a tip I've used a few times. If by chance you should break a center drill tip off don't throw it away. Instead make a removal tool from it and use it to remove the offending point. Can't remember where or when I came across this but it has saved me some headaches a few times.
You may already know this trick but though I would share just in case some one hasn't.

 

[ozzie46]

Thanks For the tip Doc. Filed for future reference.

Ron

 

[reggie98]

What about using an old MT drill as the basis for the center drill holder? Almost nothing to buy, if you start with a battered drill from a tag sale, car boot sale, fleamarket. Look for one with damage to the flutes, broken end, etc. but an acceptable MT shank. Wouldn't require much more than trimming to length, drill/ream or drill/bore to size.

 

[Thad Swarfburn III]

Keyless chucks are wonderful things. Their only drawback is that they don't work in reverse - they're strictly for clockwise turning.

Dang, never thought of that - thanks for pointing it out. Another possible mistake averted!

 

[rklopp]

Keyless drill chucks work fine in reverse as long as you don't exceed the loosening torque. I use mine all the time for power tapping in the mill. Of course I don't try it with 5/8-11 taps, but it works fine for, say, 5/16 (8 mm) and smaller machine screw taps in easy-tapping materials like mild steel, aluminum and brass.

 

[BobWarfield]

I too stuck a keyless on my Lathe Tailstock shortly after building a cam lock and really like the speed.

One drawback with the keyless chucks--they will really lock up on a big bit. You wind up needing to take a wrench too them to get them loose again. For that reason, I will ultimately purchase a big Jacobs to use when working with big bits. Certainly any Silver & Deming falls into that category for me. Probably anything over 3/8's as I think about it.

Brian, you need to build yourself a peck drilling lever for that tailstock. That'd be my next productivity enhancer for mine. Someone on here did a nice one a while back, but I have managed to forget who it was.

Cheers,

BW