I have some freshly cut maple that I want to turn into vases and urns. Can I safely use a four jaw chuck to hold a roundish blank once I turn a tenon between centers? My blanks are around 12 inches long and 4 inches in diameter! I will be using a Delta 46-460 lathe ( if this makes a difference)! Thanks for you input and suggestions!
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Four jaw chuck for spindle work?
- Thread starter Joe Ruszczyk
- Start date
In theory, yes, you can. In practice, that's a pretty long, heavy blank, especially on a lathe of that size. If you round the blank between centers first, so it's reasonably balanced, you might get away with it. You'll need a really well made tenon to keep the wood in the chuck and turn safely. If you do try it, I'd suggest keeping the tailstock in place when possibly to reduce vibration and enhance safety.
Going from green wood to finished urn or large vase is a real challenge for me. If I wax the ends on a blank and let it sit, in 4 years, I may have a blank that hasn't cracked badly. If I rough turn the blank, it'll dry faster, but then in order to minimize cracking, I've got to turn a reasonably uniform wall thickness and I'm locked into a particular shape. I wish I could go down to the local lumber yard and buy a nice, dry 6X6 hardwood blank.
It's one of the more frustrating problems, for which there doesn't appear to be a good solution here in the arid west. You at least have plentiful hardwoods, a little humidity, and some chance of success.
Going from green wood to finished urn or large vase is a real challenge for me. If I wax the ends on a blank and let it sit, in 4 years, I may have a blank that hasn't cracked badly. If I rough turn the blank, it'll dry faster, but then in order to minimize cracking, I've got to turn a reasonably uniform wall thickness and I'm locked into a particular shape. I wish I could go down to the local lumber yard and buy a nice, dry 6X6 hardwood blank.
It's one of the more frustrating problems, for which there doesn't appear to be a good solution here in the arid west. You at least have plentiful hardwoods, a little humidity, and some chance of success.
I almost always, when turning any spindle where it is possible, use a tenon. Mostly it is a better grip than the spur drive. With spindles the size you will be turning it should work. If you are turning a piece that long for hollowing, then you most likely will get vibration when you remove the tailstock. Steady rest or be VERY gentle when you hollow. 6 inches and 4 inch diameter, no problem. A bigger set of jaws will add greatly to the stability.
robo hippy
robo hippy
The lathe will only make a difference depending on how out of balance the piece is, and how much weight you have added to the lathe. The lathe my jump around until you round and balance the piece. If it is a 4” dia log that you will turn down more, I would not leave it 12”. Maybe 8-9”.
4”x12” is getting out there a bit, but I do it fairly often. I leave the TS in place as much as possible, and dont turn the bottom 1/2 down in dia until you have finished the OD top 1/2 and hollowed the top 1/2. A tall spigot style set of jaws, with an inch or more of grip, will help a lot. I would not do it with standard jaws that only allow ~3/8” grip depth.
Wet wood cuts a lot easier than dry and is much more fun. For an urn, where a top cap is usually used, leave wall t ~3/8” or so, and leave a little extra in the area where the top fits. When dry, put the between centers using a jam chuck and square up the tenon, mount in the chuck, and true up for proper top cap fit. Light cuts, take your time. The thicker wall provides enough stability to round out for the top, and an urn needs to be a bit thicker just in case it gets dropped. I dry pieces in heavy craft paper. For vases I go to ~1/4 to 3/16” wall and let it warp.
You can rough turn it to 1/2-5/8” wall and let it dry. Leave the bottom 1/3 a bit heavier . Drill the center of the bottom out, 3/4” dia or so. It will be plugged when dry. Reduces cracking. Take it easy finishing turning, dry wood generates more force, but you can get a perfectly round shape if desired.
4”x12” is getting out there a bit, but I do it fairly often. I leave the TS in place as much as possible, and dont turn the bottom 1/2 down in dia until you have finished the OD top 1/2 and hollowed the top 1/2. A tall spigot style set of jaws, with an inch or more of grip, will help a lot. I would not do it with standard jaws that only allow ~3/8” grip depth.
Wet wood cuts a lot easier than dry and is much more fun. For an urn, where a top cap is usually used, leave wall t ~3/8” or so, and leave a little extra in the area where the top fits. When dry, put the between centers using a jam chuck and square up the tenon, mount in the chuck, and true up for proper top cap fit. Light cuts, take your time. The thicker wall provides enough stability to round out for the top, and an urn needs to be a bit thicker just in case it gets dropped. I dry pieces in heavy craft paper. For vases I go to ~1/4 to 3/16” wall and let it warp.
You can rough turn it to 1/2-5/8” wall and let it dry. Leave the bottom 1/3 a bit heavier . Drill the center of the bottom out, 3/4” dia or so. It will be plugged when dry. Reduces cracking. Take it easy finishing turning, dry wood generates more force, but you can get a perfectly round shape if desired.
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I urge you to start with smaller pieces 4x4x5 and work up to the taller sizes.
a good 4 jaw Chuck will hold spindles well. A severe catch can pull a piece partly out of the Chuck letting the end whip around.
this is a much more dangerous with a 12” piece than a 6” piece.
end grain hollowing and the tools you use for it has it own learning curve.
hollowing a 6” you can use a 1/2” tool, 9” deep a 3/4 “ tool, 12” deep I use 1.5” bars.
consider doing 4x4 pieces of increasing lengths of 5, 6, 7, 8, 10, 12. Getting comfortable and proficient before going to the taller pieces.
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@hockenbery is right, work your way up to deeper hollowing. You need hollowing tools to get more than a few inches deep, particularly if you want the opening smaller than the body.
For hollowing tools, there are hand held, captive, and articulating (pivoting joints). There are many designs and choices, worthy of research and study on its own. Its an “in depth study”!
For hollowing tools, there are hand held, captive, and articulating (pivoting joints). There are many designs and choices, worthy of research and study on its own. Its an “in depth study”!