Sorby Steb Center Modification

[Don Geiger]

I have a couple of Sorby Steb Centers in different diameters and really like them for spindle work. One thing that has always bothered me though is the amount of pressure the spring-loaded point puts on the work piece. Today I was turning some very thin finials and had one collapse when I was narrowing down the top to a nice fine point. I decided it was time to experiment!

I pushed the point and the spring out by using the small diameter knock-out rod that comes with the One Way live center. The spring is very heavy and I thought about running to the hardware store to get a lighter one. Then I thought that I would first try shortening the spring so it doesn't have to compress so much. I used a pair of side cutters and (while wearing safety glasses) cut bits of it off. I tried it in the Steb center a few times until I got close to what I wanted and then using my grinder fine tuned the length of the spring.

While I had the spring and point out I sprayed some Ballistol oil into the bore and ran a wad of cloth through it a few time to clean it.

Now the point is a little past the teeth and the amount of pressure to compress it is much less.

Don Geiger

[David E Keller]

Sounds like a good idea... Thanks.

[Lance kanaby]

Hey Don, thanks for the heads up on the steb center spring tension. I have all three sizes and for small diameter spindle turning I use the 1/2" size and have not had any problems. I am sure if I used the bigger sizes it might split the wood. A lot of this has to do with how much pressure is put on via the tail stock too.

[John Keeton]

Don, sounds like a good fix. I am curious, though.

When I turn finials, I usually use a pen blank. I square the end, and lightly chuck it up in the inner jaws of the chuck. I then use the tailstock to center the blank, and tighten the chuck.

With the tailstock in place, I round the blank, and take some stock off to get it in the general, but heavy, shape of the finial. Then, I remove the tailstock, and turn the finial with no tail support.

I found early on that I could not leave the tailstock in place for a thin finial.

[Steve Schlumpf]

Don - glad you found a way to lesson the pressure!

Haven't tired a Sorby Steb Center - so have no idea if my knockoff is close to the same but I have a WoodRiver multi-tooth drive center (http://www.woodcraft.com/Product/2021122/24537/WoodRiver-Multi-Tooth-Drive-Center-1-Diameter-2MT.aspx) and it has a set screw that allows me to adjust how much of the center point is exposed. This then also determines how much pressure is required to push the pin back into the drive so the teeth can engage.

Seeing as how I have never seen a Sorby Steb Center - I was wondering if the amount the point is exposed was adjustable?

[Wayne Spence]

Don -Good tip, thank you. I have problems getting a good bite on dense hardwoods such as rosewood, cocobolo. Any tips there?

[Don Geiger]

Hey Don, thanks for the heads up on the steb center spring tension. I have all three sizes and for small diameter spindle turning I use the 1/2" size and have not had any problems. I am sure if I used the bigger sizes it might split the wood. A lot of this has to do with how much pressure is put on via the tail stock too.

Hi Lance:

The point didn't split the wood (although in some cases I guess it could), but the amount of pressure I had to put on the wood to compress the point to engage the teeth was so great that when I turned a finial with a very small diameter tip it collapsed at that point before I was finished with it. I just think that since the teeth are what holds the piece and point is just there to keep the blank centered until the teeth are engaged, why does the spring have to be so strong?

I only shortened the spring on the 1/2" diameter drive. I don't see any reason to do this to the larger ones. My wife also uses the 1/2" one to turn knitting needles and they too have to come to a point.

Good to hear from you!

Don