Method of rapidly centering regular shaped stock for turning

Hi Leo When I'm doing a run of between centers spindle turning, my four jaw chuck really is lying around. My scroll chuck is a wood-turning chuck with serrated jaws, however, it is easily eased open or closed a tad by a slight nudge on the scroll plate tommy bar. See photo 5 on link

. Should you want to indent the workpiece when mounted, I suggest, rather than using an allen wrench and the Center Plug I made up, drill a hole through the center of a Center Plug and make the indent with a sliding fit sharpened steel rod. (A sort of very long center punch) and a hammer. Thanks for your interest. Exbrat

I guess I'm sort of confused as to use... You replaced a center finder with a scroll chuck and pointed nipple?

There has to be something I'm missing here... this is for finding and marking center for spindle turning, right?

If I am understanding this, couldn't you put the stock to be cantered in the chuck and center punch it from the back of the chuck?

mac

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Great Minds Think Alike...

Good point on the chuck, too.. I'd never used a metal chuck and had little idea how it functioned compared to a wood lathe chuck..

mac

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Ahh... that brought on up from the memory banks..

A teacher that did a lot of lamps showed my his knock-out bar and it had a very small hole in the end with a pin in it.. he ran it through the spindle as if he was knocking out a Morse taper and it center punched his lamp body for drilling..

mac

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So it's no good. The Sorby steb center has the same problem.

You must have missed my post to Leo on 27th. That's exactly what I suggested. That approach is ok if your self-centering four jaw chuck is left mounted most of the time, even for a job lot of a couple of dozen spindles using a drive center such as the Robert Sorby steb centre.

As I see it, using that approach I'd have to:-

1. Mount each blank. Close up the tail stock (guessing the center at the tail - better removing tail center and using empty tailstock to take hammer blow otherwise you will end up with an off center indent at the tail end).
2. (In my case remove outboard accessory). Insert spiked rod and give it a hammer blow. Open up the tail stock and reverse and do other end.
3. Repeat 1. and 2. a couple of dozen times.
4. Fit drive center and start turning.

Time is money. I'd beat that hands down. 3 or 4 seconds per workpiece to center mark and indent (providing I'm not making four-poster beds!).

Ref your post on 27th about the Veritas Center Marker. Good link. Thanks. Excellent, simple idea.

You said "Ok for spindle work, but sort of useless for bowls, IMO.. "

Would be easy enough to knock one up with 8" sides to take up to 16" bowls. Just needs a sliding marker knife. e.g. a 1" to 2" piece of hacksaw blade, sharpened to a knife edge and clamped at about the workpiece center (with, say, 1/8" protruding) in a narrow diagonal groove bisecting the 90 deg cradle.

Exbrat

If you cannot use the center hole of your chuck to house a spiked insert could you perhaps mount a spike on a steel plate, possibly a cruciform shape to avoid the jaws when they close, and position it snuggly (interference fit) on the front of the chuck backplate. It would be possible to do that on my chuck but I am not familiar with the Nova.

Exbrat

Whatever works for you, I guess... A minute or 2 with a center finder works for me.. Everyone turns with different techniques and goals and mine is to relax and not stress.. If it isn't fun any more I'll find something else that is.. If I ever get into the "time is money" production mode, I'll import my stuff from China.. YMWV

mac

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