John K Jordan
12-23-2015, 8:35 PM
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.
327798
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!
327799
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.
327800
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.
327801
(Continued in part 2 of 3)
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.
327798
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!
327799
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.
327800
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.
327801
(Continued in part 2 of 3)