using a draw bar in the tailstock

[iclark]

I just had a Doh! moment in another thread when SceneryMaker pointed out that the quill length in the tailstock changes during use. That makes a draw bar problematic for many applications.

I had suggested using a draw bar to keep a drill chuck from pulling out of the quill when drilling with a large Frostner bit. I've actually had more of an issue with large twist drills or brad point bits wanting to pull the drill chuck loose from the MT2.

With twist or brad point bits, my hand on the drill chuck is normally far enough away from the spinning wood that I just need to pay attention.

With a large Forstner bit roughing out a hollow form or bowl, I find myself wishing for some other way/place to use my hand to keep the drill chuck in the MT2.

Now that SceneryMaker woke me up, it occurs to me that a draw bar could have a handle to hold rather than using a nut tightened against the quill. That would get my hand that is restraining the drill chuck well away from the spinning wood.

The main use I have for a draw bar in the tailstock is for inside-out turning. I mount a lightweight 4-jaw chuck on a live center in the tailstock to hold that end of the 4 pieces during the first turning (the inside out step). That means that I don't have to do any gluing for that step. I like to keep some tension on the blank while turning. There can be a very fine line between putting the blank in tension and pulling the quill away from the live center.

[SceneryMaker]

I have a MT2 adapter for my headstock with a 1/4" thread for a drawbar and a 5/8" straight shaft for the output. It came with my Beall buffing wheel kit but it also fits the Jacobs chuck that came with my old (Does 1953 qualify as old?) Shopsmith? I know those chucks are still available.

I also I have an adapter to mount my Nova chucks in the tailstock but I can't remember where I got it. This would make it practical to mount my work in the semi-stationary tailstock and hold the drill chuck in the headstock with the drawbar. This makes the whole thing work backwards from normal but I've been told before that I'm not normal.

This should not threaten to dislodge either the drill chuck or the work.

Food for thought.

[hairy]

Ernie Conover uses a drill pad in this video   https://www.youtube.com/watch?v=G-fpyMS5W4w

It goes in the tailstock to hold the workpiece for drilling. The drill bit is in the headstock.

In one of his books he describes a crotch center. Basically the same thing, but made to hold cylinders and dowels for drilling on the lathe.

[crokett™]

IMO, if the drill chuck is pulling out of the tailstock while you are drilling you are doing it wrong. You should be backing the bit out of the hole frequently enough to clear chips and prevent galling that it won't pull the chuck out of the tail stock. I can see a use case for some kind of drawbar when you are using a chuck.

[Arlin Eastman]

This is what I use for bits and extending them which hold them very securally 

https://www.drillbitsworld.com/Products-...rills.html

Search | Wholesale Tool (wttool.com)

https://www.wttool.com/search?q=jobber+b...genumber=1

Wholesale tools used to carry the MT 1-5 taper bits but do not anymore so I switched to Drill bit world

If you wanted a dedicated mt taper and drill bit just glue it in and it will never move

[Arlin Eastman]

Thanks for Ernies link Hairy.  I keep forgetting to watch is videos.

[Dusty Workshop]

Make sure that your taper in the tailstock is clean.