Another newbie question

[Shane Copps]

OK guys,
First, thank you for helping me with the centering issue. I remounted the log on the lathe (SS) like you guys told me to, Then as the lathe was chattering around a little vs. jumping across the shop, I added a little weight and Viola- I have been able to beat the log into a mostly round stick that is about half the size it was.

Here is my new dilemma- As I worked the wood, the live center kept tearing out and then the wood would quit turning. I tried hammering the live center in, but I can only get it to go in about 1/4 inch and then it stops and when I pick up the log, the center falls out. I line the marks in the center back into the log and sandwich the log between the centers. It turns for a while and tears out. I thought this was possibly because of some soft parts in the center of the wood, so I mounted some blocks on the log- centered the log again and started back up- now the live center is still tearing out of the blocking. I also noticed that every time the live center tears out, I am getting a deep burn on the other end. I also noticed that the log/blocking is riding up the "Dead" center and after a short time turning, the "Dead" center seems to be causing a friction hold on the log- which isn't helping my tear out on the live end.

The live center I have has a point and then four blades that go straight into the wood, and the "Dead" center is a point that goes up inside of a hollowed out socket area. It is when the log rides up to the socket area that I start having the friction hold from the center.

Any ideas on what I'm doing wrong?

Thanks
Shane

[David Bassett]

It sounds like you need a larger heavier duty drive center. Maybe a faceplate?

Also, (I assume) your terminology is opposite what I'm used to hearing. I just checked CraftSupply / Woodturner's Catalog and they use "Drive Center" and "Revolving Center", probably to avoid any confusion. I'm used to Live & Dead centers to be used in the tailstock to hold spindles. The difference is a live center has bearings and spins where a dead center is fixed and the wood spins on it. If you are using a dead center in your tailstock you are adding friction that may contribute to your problem. (If you are using, what I know as, a live center in your headstock spindle it will spin and I'm surprised it drives your wood at all.)

Until you get a sturdier drive sorted out the only option I can think of is lighter cuts.

[Thom Sturgill]

First off terminology -

Drive center - in headstock, can be spurs, safe center (ring) or steb center
Live center - in TAILSTOCK uses bearings to spin freely
Dead Center - mainly used in metal machining, this is a solid piece of steel with a 60 degree point.

It is normal for the drive center to work its way into the wood some. Lyle Jameison has a good video on mounting the wood and setting the center. I personally do not like driving it in with a hammer. It does not take much to mushroom the taper to a point that can gall the spindle. A wooden mallet is fine.

https://www.youtube.com/watch?v=b4xIHTS0yJc (https://www.youtube.com/watch?v=b4xIHTS0yJc)

[Kyle Iwamoto]

Periodically, as you rough, the drive center works it's way into the wood as you found out. Frequently, in the beginning, stop and clamp down on your lever to clamp the piece harder. On a SS it's a pain, since its a 2 handed operation, but as you work, the drive center will eventually seat down far enough to stay "in place" so to speak. I've found that the lever actually puts a lot of pressure on the work, and I never had to hammer on the spur drive. Which as already mentioned, you should do with a mallet.

[Shane Copps]

Ok- This tells you how new/how long it's been since I have done any turning.

What I seem to have from your descriptions are a Drive Center with a point and 4 spurs. and for my tailstock I have a dead center. I'm gathering that I need to find a live center for the tailstock to cut down on the friction?

And Thom- I am using a soft handmade wooden mallet to tap it in.

Thanks
Shane

[Shane Copps]

This seems to be the issue. The work piece works up the tailstock center and walks away from the drive center and then it spins or tears out.

Thanks

[Thomas Canfield]

One demonstrator at SWAT several years back suggested using a 1" spade bit to form a recess for the "drive center" to retain it should you get a catch. That also get down below any bark or soft outer wood and provides a flat surface for all the drive points to engage. I use a 2 prong drive center (bought from PSI) which seems to get a good bite and allow some variation in mount if aligned with grain. I do also recommend a large Forstner bit to form a flat for a faceplate or a worm screw in chuck. Unless the wood is fastened to faceplate or wormscrew, you do need to keep checking the tailstock pressure on live center to be sure the drive spurs are firmly engaged.

[Dave Cullen]

This seems to be the issue. The work piece works up the tailstock center and walks away from the drive center and then it spins or tears out.

Thanks

When turning a spindle or any long grain piece, the tailstock center point will penetrate the grain a bit and the piece will get loose in the lathe as you've noticed. You have to periodically give the tailstock wheel a tweak to keep it tight.