HOW I TURN LONG, THIN SPINDLES, part 1 of 3

[John K Jordan]

Someone asked about techniques for turning long, thin spindles. I took the camera to the shop and got some pictures to explain the process I use and wrote down some steps.



HOW I TURN LONG, THIN SPINDLES, part 1 of 3
John K Jordan
12/23/2015

Turning long, thin spindles can be a challenge. The shaft can flex, chatter, and vibrate causing lots of problems and perhaps even breaking. These notes are to show the way I usually turn thin spindles.

I use a magic wand as the example but much of the same applies to conductor's batons and other spindles.

This photo has a few examples, in cedar, purple heart, dogwood, and cherry. The one on the bottom is the one I did for this tutorial. As an example, I made it thinner than usual which was more of a challenge. I also didn't spend much with detail or making it look well balanced. It shows!

The second one from the bottom is a finished wand before the support is removed.

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There is one basic problem: how to keep the wood from vibrating or chattering while turning.

Start with good wood. Pick a blank with the grain running as close as possible along the axis. Grain at an angle, figured or burled, knots, punky, spalted, lots of wormholes, and such can make the shaft weaker and it can flex more easily and break.

BTW, for magic wands I remove much of the wood at the shaft first on a bandsaw so I don't have to remove so much wood on the lathe. This saves a lot of time. It also gives me lots of cool strips of wood to pass out to the kids!

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Hold one end as firmly as possible in a chuck. If held between centers, you have two end points and the wood can easily flex. If one end is held tightly and the other in a center, the first 1/3 to 1/2 is restrained from flexing and the whole thing is a lot stiffer. This is just common sense.


I do not actually hold it in a standard chuck but use a jam chuck. I turn a short #2 morse taper on one end then jam that into the headstock spindle. This has several advantages: One, it eliminates the chuck and rotating jaws and gives more working room. Two, I can turn longer shafts on a smaller lathe, for example, when I make magic wands on a mini lathe out in public. (I make up blanks ahead of time on a bigger lathe.) Three, a real advantage is the piece can be removed from the lathe and returned with perfect registration, something not easy or possible with a chuck.

I made a small gauge from a piece of brass which lets me make a perfect taper every time. Before I made the gauge I sized the taper with calipers at two points. I always use a parting tool to cut a small relief between the high and low ends which lets it seat better in case the taper is not perfect.

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For this exercise I picked a cherry blank I already had in my stash of wand blanks.

These photos show the blank with the morse taper cut, then jammed into the lathe spindle. Bring up the tailstock to seat it firmly then release a little. Too much force on the tailstock can cause problems when the shaft gets thin.

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(Continued in part 2 of 3)

[John K Jordan]

HOW I TURN LONG, THIN SPINDLES, part 2 of 3

I turn at the highest speed possible which is 3200 RPM or so on my lathe. The inertia from the rotating mass tends to make the shaft stiffer. Also, spin fast and cut slow for the best finish.

Make everything round and for a magic wand, rough out the handle. The handle can be finished cut first but I usually like to wait until I develop the transition between the handle and shaft.


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Begin tapering and shaping the shaft. I generally use a skew chisel. As it gets thinner the fun begins.

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When it starts to get thin the shaft will probably vibrate and chatter during the cut or it may even vibrate on its own without even touching it. Sometimes loosening the pressure from the tailstock helps if you have it too tight.


Some strategies for handling the vibration.

First, I do not do what I saw on a YouTube video - just sand to size with 80 grit paper. Ack. I rarely use anything coarser than 400 grit, often finer. If you have not yet developed spindle turning skills, the 80-grit gouge may be an option.

Make light cuts with very sharp tools. I almost always use a sharp skew for thin shafts. A spindle gouge will work but is sometimes more of a problem since the narrow tip can dig in more easily. The skew can support the wood with a wider bevel and the straight edge is more forgiving. A skew ground with a larger angle (say 45 deg instead of 30 deg) will be more forgiving.

A roughing gouge will also work. It's kind of like a curved skew.

I cannot turn these without using the "left hand steady rest" method. I rest my left arm on top or against the headstock and cradle the spindle lightly with my left hand. (This is perfectly safe. Don't wear long sleeves!) I use my left thumb to lightly support and guide the tip of the skew. This provides excellent fine control.

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This, of course, requires holding the tool with the right hand only. I grip very near the tip and support the end of the handle by forcing it against the underside of my forearm. This supports the tool well.

Note that as the tool is moved along the shaft, the left hand has to move with it. This support is very light and the cut is very light. As Richard Raffan said once, if the wood gets hot from friction on your hand, you are using too much force with the tool!

Sometimes the shaft will want to vibrate even when supported with the hand. As before, I try either tightening or loosening the pressure from the tailstock.

Then I try different things to see what works the best. Sometimes I will switch to another tool, say a skew with a different angle. Sometimes reversing the direction of the cut will make a big difference.

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When working on the left end, I might support the right end by crossing my hand over the tool.

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(Continued in part 3 of 3)

[John K Jordan]

HOW I TURN LONG, THIN SPINDLES, part 3 of 3


I have had some very thin shafts vibrate regardless of what I did. I don't worry about it too much when shaping but it's horrible when doing the finish cuts. Instead of resorting to sandpaper, I use a small cabinet scraper.

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One oddity: if you do happen to put sudden force on the side of the shaft perhaps with a catch or some enthusiastic turning, it may knock a bow in the shaft and make you want to give up. However, this can be fixed. I simply tap the shaft several times in the middle with the tool handle while it is spinning. Usually several strikes will hit it just right and knock it straight again. If necessary, release a little tailstock pressure first. Some woods are worse about this. It's not often a problem but a good thing to know.

After the shaft is done I finish turning the handle then apply a finish on the lathe, usually Mylands shellac-based friction polish. Remember the shaft is fragile so to avoid side pressure just squeeze the finishing cloth around the shaft. I always use a small piece of cloth for safety, although with thin spindles like this the shaft will break before you can rip your fingers off with a large cloth!

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If texturing, be sure to support the spindle. I sometimes use a star wheel texturing tool.

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I cut off the tip with the skew, then thin and saw off at the handle. If the end is broken off, you risk pulling out fibers and causing damage that cannot be fixed easily. I sand and finish the ends by hand.

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Here is the end result. Done in a rush, nothing spectacular, but I hope this explains the technique I use.

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I have made many wands like this and these techniques work for me. As they say, your mileage may vary!

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John K Jordan

[Doug Ladendorf]

Thanks John! Great stuff.

Doug

[Brice Rogers]

Thanks for your highly informative post.

[Peter Blair]

Fantastic John! Thank you so much for sharing your technique I do a lot similar but have been using stock the isn't square and between centres. I'll have to try cutting my stock longer and turning a morse taper. I can sure see how reducing the pressure will make for a lot less flex. Last one I did I used a spindle steady, was a pain but helped.

[Robert Henrickson]

Thanks! Clearly written and illustrated.

[Dave Fritz]

Very informative, thank you.
Dave Fritz

[terry mccammon]

Much appreciated. Thank you.

[Russell Neyman]

My fellow club member, Ralph Lindberg, shares this great tip that helps stabilize thin turnings, such as finials. He has a free-spinning jacobs chuck mounted in the tailstock, lightly clamping that onto the farthest end of the object. Then, he adds an ever-so-slight tension to the end, pulling it. This tension really helps fight the wobble. Ralph may jump on here and add a photo.

[John K Jordan]

adds an ever-so-slight tension to the end, pulling it.

That would help a lot, especially on longer pieces. You might have to have a drawbar or something to keep the chuck from pulling out of the tailstock. Fortunately for most spindles the hand support method works well.

JKJ