by Fred Holder

The Spindle Tensioning Device is designed to provide a live chuck at the tailstock to allow one to apply tension  to a thin spindle by pulling on the spindle with the tailstock. The nose is threaded to take a 1/2" Jacob's Chuck with a 20 tpi attachment thread. The Morse Taper seats into the tailstock taper and the threaded rod pulls the Morse Taper firmly into the tailstock and holds it there when tension is applied to the spindle.
 

A tool that I’ve been looking for and have jury rigged up a time or two just never seemed to come onto the market. When I turn long thin spindles, I had felt that a pulling piece at the tailstock; i.e., a “live chuck”, if you will, that would grab your spindle and apply tension to it would make the spindle more stable to turn. Finally, I harassed Folker Weiss of F.H. Weiss Engineering Services or Ashland, Oregon into making me up one to my general design. It arrived just before I went to the AAW Symposium in Tacoma, but I’ve had quite a bit of opportunity to try it since returning. Let’s say it did everything that I thought it would and perhaps a bit more. Folker was a bit hesitant about offering it for sale in general, because many lathes do not have a drilled through tailstock. For people with one of those, the tool will not work. Finally, I got him to give me some model numbers and prices and ordering information. Here goes:

CUSTOM SPINDLE TENSIONING DEVICE, MODELS STD-1,-2, OR-3.
Price $220.00, includes the basic tool with the 5/16-18 x 12 in. tension rod and hand nut, the tenon turning center, insured shipping within the continental USA* by priority mail or UPS ground, money back 30 day “examine it in your shop” guarantee if returned undamaged and postage paid (Folker's standard guarantee), brief description and instructions. Payment method: Check or money order prior to shipping. Sorry, No Credit cards or  COD.
Available for MT-2, MT-3, also for MT-1 as above except with a 1/4-20 tension rod and nut. These items may not be in stock at all times, a shipping delay of several days must be expected.
Also available: Matching 1/2 in. capacity key chuck with 1/2-20 threads. Price: $25.00 with no extra shipping charges if ordered together with the basic tool.

You can no longer order these tools from Folker, he has had to give up working. We appreciated the fine tools that he made for us when he was making and selling tools. If you get a chance to purchase one of these tools, grab it up because he is no longer producing them.

I’m sure this idea isn’t original with me and others have probably been using it for many years, but to my knowledge there has been no one commercially manufacturing such a Tailstock Tensioning Device. I am pleased to get Folker to add it to his line of fine products. Another one of his products that I’ve been using for some time is his LTC (Live Tailcenter Cup) which is available for #1, #2, and #3 Morse Tapers. I use mine quite a bit, especially when turning balls. It is also a nice backup to hold a bowl in place on a jam fit chuck to turn the foot.  He now also has available a new, lower priced cup, designed to fit the Oneway live tail center.

Although I used this device as a live center to turn the tenon on my pieces of wood, Folker does not consider this a practical application since it could push loose the press fit bearings. In his words: “The device is designed for tension, not for compression, while the bearing can be loaded in either direction, the taper end and the threaded end are press fit into the housing and the bearing from the inside out. So, if the compression load exceeds the holding capacity of the press fits, the shafts will be pushed in. That may not be noticed until the two shafts touch, gall from the friction, and generally ruin the tool.”
He recommends the use of a wood screw held in the chuck to place a pulling tension while the tenon was cut. He felt that the use of the tool as a live tail center might put excessive pressure on the tool and ruin it. He therefore does not recommend this use. So far, I’ve experienced no problems with it, however, I’ve kept the pressure to a minimum recognizing what he has told me.
This new device has really made turning long thin spindles a much easier task. I’ve never been able to master Richard Raffan’s technique of turning long thin spindles. They always bowed and finally broke on me.

This view shows the Spindle Tensioning Device in use. The spindle shown here was turned down to 0.175 inch in diameter before beads and "v" cuts were made in it. Once it became thin, the lathe was never stopped. No support was used on the back side of the spindle when turning. I did support the spindle when making beads and "v" cuts. I thought this the better part of valor. The 0.175 inch part of the spindle only measured 6-1/4" in length.  But without the Spindle Tensioning Device, I could not have turned this spindle this thin without some support of the spindle to reduce vibration and bowing.

I don’t guess a 6-1/4” spindle is really that long, but when it is 0.175 inches in diameter before turning beads and “v’s” is it pretty long for me. I deliberately did not give the spindle any support with my hand while turning, but simply applied the skew to slice away the excess. I did feel it was the better part of valor to give some support while cutting the beads. Besides I wanted my sample to take to “show and tell” at the club meeting.