>Brad asked about making a "Tensioner" for spindle turning. There are two ways to do it. Both require a Oneway tail-center.
The end of the Oneway center is threaded 3/4-10NC. Drill and tap the tenon on the spindle or make a sacrificial waste block to fit the thread on the center and attach it to a tenon on the spindle.
Make a draw-bar for the tail-center by fitting a piece of all-thread rod into the hole through the center and lock it in place with epoxy. JB Weld is good for this, but the draw-bolt will become a permanent part of the center.
If you have a second chuck, Oneway makes an adapter so a chuck can be attached to the tail-center. That way it won't be necessary to drill and tap the waste block for every spindle.
However you do it, you will need a chuck that gets a good firm grip on the wood. I use two (2) Talon chucks with the #1 or #2 jaws to apply the tension.
Most interesting. How thin have you turned doing this. Have you noticed a reduction in chatter on whatever size your turning. I find this interesting and have followed it for years but have yet to try it. I wonder how hard it would be to rig up either a Beal Collet or and R-8 collet to this method.
>Let's put things in perspective. It has becone an "Urban Legend" among woodturners that tension can solve all of our vibration problems, and eliminate the need for a steady rest. Neither is true. Tension is just another trick that we can use when turning long skinny pieces of wood.
Adding tension eliminates any bowing of the wood from pressure between the centers. And, it stiffens the wood and makes it more difficult to move sideways from tool pressure, the same thing that happens when we apply tension to a bandsaw blade. Less movement means less vibration.
Tension will do nothing to the "twist" that is put in the piece of wood from tailstock friction, and cutting forces.
Using a chuck at the tailstock can have the effect of adding the mass of a flywheel at the end of the wood. This can have a smoothing effect of changes in cutting forces and can act as a vibration damper.
It is possible to add too much tension to the wood, causeing it to vibrate like a plucked guitar string when the tool is applied to it.
For myself, tension has been very effective for chair parts and other things of similar size and length. I turn the stretchers and back spindles for a Windsor Chair with tension. It has no value on the legs for the same chair because I can turn them between centers.
I have never applied tension to something as thin as a knitting needle. I would support the wood with my fingers and make the cuts lightly with a very sharp skew.
>I don't dissagree at all. I've had the force of the tailstock rip a thin spindle in two and it doesn't weigh as much as a chuck. Windsor chair parts are probably 3/8" or more. I shape mine on the shaving horse. Haven't tried turning one but thought about it because I wanted a chair with a Cat tail look to the back.
I can see where it would help reduce chatter. Hadn't thought of the guitar effect. Can you just tune it like a banjo.
I'm trying to figure out if a compression fitting could be mounted to a nut to fit the Oneway tailcenter. I already have the nuts. Or maybe that should be I'm already nuts. Anyway well see when I get back from the symposium.
>Several years ago, I was turning a number of thin spindles for drop spindles. The pressure from the tailstock caused these spindles to bow and made it difficult to turn them as smoothly as I wanted to. I contacted Folker Wiess and asked him if he could make one for me. I described what I wanted and he said he would give it a try. The story about this device is at the link below.
The use of a Oneway live center with chuck adapter screwed on and then a chuck mounted to the adapter should work quite well if you can add a threaded rod to hold the live center in the tailstock. But if you don't have a Oneway Live Center, a chuck adapter, and a small chuck to screw onto it. The spindle tensioning device that I had Folker make up for me would be a bit less expensive. I turned spindles less than 1/8" in diameter and six inches long without any support on the spindle except the tensioning device.
>Russ & John, I'm not only a nut, my threads are stripped! but I can still wonder. I suppose that the length of a very thin spindle and the distance from supports a cut is being made are both related to the degree of bowing and axial distortion. If so, a blank roughed thin enough to fit inside the headspindle and fed thru a collet or compression nut might supplement or allow omitting tailstock tensioning by keeping the 'exposed' length short and the cutting site near headstock support. I'll conveniently forget any outboard whipping of a long blank. What else did I forgot?. Arch
>That's exactly what I did when I turned a conductors baton. I cut the wood 3/8 square and then held it on the jaws of my chuck and extended a couple of inches. turned this and then did the same. when it got long and started to whip I pulled the center pin out and put the point of the wood loosely in the center to keep the whipping down while I turned the rest of the baton. it was 12" and tapered from 1/4" down to 1/8"