Drive center slipping.

Re: Drive center slipping.

Peter Teubel

>Bang the drive spur into the wood ALOT harder (off the lathe, of course, and using a wooden mallet). I always embed it at least 1/4". If I'm using green wood, I use a 2-spur drive and embed it 1/2".

Re: Drive center slipping.

John Lucas

>Bill

I either drill or hand chisel through the soft wood when I'm doing natural edge bowls. I always start with the bark toward the drive center.

I don't usually have that problem on bowl blanks that have been cut out of solid wood. I have had it happen on endgrain and have considered buying one of the big drive centers from bestwood tools but I don't do enough of this style turning to justify it yet.

Re: Drive center slipping.

Ric Erkes

>I was thinking about sending this idea to John for an AAW submission, but since you asked.

I start by drilling a hole the diameter of my spur drive about 1/4" deep. That locks the spur drive in position. To keep the spur drive from spinning in the wood I put a few drops of CA glue in the hole. That hardens up the wood and haven't had a spur drive spin out since I started doing it.

Ric

Re: Drive center slipping.

John Lucas

>Ric

That sounds like a good one. If you wantme to submit it send it to this e-mail along with your address so I can put it in my tips file. Carl is going to be asking for more tips any day now and I promised I would get them to him sooner.

Re: Drive center slipping.

Glenn Hodges

>Great idea Rick, getting ideas like this is why Wood Central is such a good forum.

Nashville, Ga.

Re: How do you shift the center?

Al Crandall

>If the location of the center is locked in by a counterbore, what do you do if you want to shift the centerline by 1/2" or 3/4" after you see how the grain relation to the bowl shape is developing? One of the great things about starting a bowl between centers is the ability to shift the center position easily to fine tune the grain pattern.

Re: How do you shift the center?

Ric Erkes

>Every once in awhile, I do need to shift the spur drive position. I use a spade bit to drill the hole and sometimes it will be necessary to chisel a flat spot for the tip to start a new hole, but the two holes can intersect.

Most of the time I can shift the orientation from the tailstock. This is especially true with natural edge bowls. I shift the tailstock to level out the two high sides and the two low sides. But all that can be done from the tailstock while leaving the spur where it is. Maybe it is the way I approach it, but it is pretty rare that I need to adjust the spur drive position.

Ric

Re: Drive center slipping.

Mike Schwing from Maryland

>Of course John has been using the smallest jeweler's screwdriver for a spur lately to turn his goblets.

Re: Drive center slipping.

Jim Rutten

>After finding the center I take my spur drive and whack it into the wood to score it. Then I use a punch to deepend the middle hole and a screwdriver that is about the right size to deepen the straight lines. Then put the spur drive back on the lathe and put the wood onto the spur drive. Good luck, Bill.

Re: How do you shift the center?

Whit

>One other thing hasn't been mentioned here is the depth of the blades on the spur drive. I also have a DVR. The drive that came with it was way too shallow - only about 1/2". I replaced it with a much deeper 4 prong drive (happens to be one made by Delta, purchased at my local Ace Hardware for under $20) which works great. A couple other thigs I do are, when mounting a log (green wood, what I turn mostly) for bowl turning is 1. Chisel away the bark and phloem down to solid sapwood in the AREA either the spur drive or the tailstock will be. That way I can relocate either the drive or tail center or both to get optimum grain alignment. 2. After mounting the piece between centers and tightening the tailstock as much as I can, I lock the spindle and rock the piece back and forth, hard, to work the drive deeper into the wood. I then retighten the tailstock. Doing this (and the deeper drive blades) has eliminated any tendancy for the spur drive to "drill" itself into the wood.

Hope this is of some help.

Whit

Re: How do you shift the center?

Arch

>To prepare a blank I pound a duplicate spur drive well into the blank to prepare it for mounting on the lathe's spur center. To protect the duplicate I thread a short bolt into its drawbar hole. Lathe head spindles have a robust nut or integral flange for registering fixtures against and to prevent axial movement toward outboard. I'm afraid to do it, but why can't I pound the blank onto the lathe spur center to begin with? I wonder if this pounding exerts more pressure than tightening a tailstock screw. Maybe its the bang, but I'm not talking sledge hammers. Has anyone here actually damaged a lathe's spindle, bearings castings etc. by doing this or is this possibly another turner's legend? Arch

Re: How do you shift the center?

Dinyar Chavda

>Thanks, Arch, for raising this issue. FOr years, now (since I bought my lathe in '96), I have been doing just that, i.e., adjusting the position of the wood while it is between centers, tightening the tailstock initially by hand, and then whacking the wood a few times with a hammer while rotating the wood (and tighten the tailstock as I do so). I have heard about the potential damage to the lathe, but, if you look at one of Dave Ellsworth's earliest videos (Tips for turners--the one on bowls) he does just that! I figured, if it works for him.....

Dinyar