Jaws
- Thread starter RLBerg
- Start date
Help Support Home Model Engine Machinist Forum:
Yes. Chuck jaws that would close to smaller than whats on the chuck now. As it came with the lathe. I may have to think on this a bit and come up with somethingg that will work to hold smaller pieces. Put a though in my head.
Thanks Herbiey.
Thanks Herbiey.
Due to the small flats on chuck jaws they can't go down to nothing, but a friend required just that.
Using a tungsten cutter on the mill and setting each jaw to the right angle and height on each side, I was able to remove metal from each angled part until the flat wasn't there any more. I accurately measured the flat and halved it, using that setting to cut down to. A bit tough to machine, but definitely not impossible. It could have been even better if I has slung it onto the surface grinder and done all 3 at the same time.
By taking my time setting up for the cuts, the finished result on his 3 jaw was less that 1 thou TIR, better than when we started.
John
Using a tungsten cutter on the mill and setting each jaw to the right angle and height on each side, I was able to remove metal from each angled part until the flat wasn't there any more. I accurately measured the flat and halved it, using that setting to cut down to. A bit tough to machine, but definitely not impossible. It could have been even better if I has slung it onto the surface grinder and done all 3 at the same time.
By taking my time setting up for the cuts, the finished result on his 3 jaw was less that 1 thou TIR, better than when we started.
John
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I can't find a picture right now but a guy made some jaw add-ons to solve
that and other issues. He had some alum hex bar that was large enough
that he cut three 'pucks' off the bar, drilled biggish holes in the centers (big
enough to fit over the end of each chuck jaw). By putting one of these hex
bits over each jaw end he could close the three hex 'extensions' together.
The hex corners came together in the center allowing him to hold tiny things. And since there were six corners on each hex he could special
bore them for different things.
I hope that makes sense and maybe someone will remember and be able
to find a picture for you.
Pete
that and other issues. He had some alum hex bar that was large enough
that he cut three 'pucks' off the bar, drilled biggish holes in the centers (big
enough to fit over the end of each chuck jaw). By putting one of these hex
bits over each jaw end he could close the three hex 'extensions' together.
The hex corners came together in the center allowing him to hold tiny things. And since there were six corners on each hex he could special
bore them for different things.
I hope that makes sense and maybe someone will remember and be able
to find a picture for you.
Pete
purpleknif
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Shim the workpiece maybe ?
Another thought occurred to me...
If the diameter of the wood is known, (for example, if you plan to turn pen bodies that are 3/8 inch in diameter), you could take a larger diameter length of round metal stock, maybe one inch long, and drill it longitudinally for the outer diameter of your wood. Then place this in a vise, and use a hacksaw to make a slot lengthwise in the part. Clean up any burrs inside with a jeweler's file. Now you can slide your wood into the adapter part you just made, and chuck this into the existing 3-jaw chuck. Just make sure that the slot is between the jaws, and not under one of the jaws. Tightening the chuck will tighten the adapter and grip the wood.
I have a few of these adapters that I have made over the years to save me time when I don't want to be bothered changing to my collet chuck to make one or two small-diameter parts. They work pretty well, and I have held material down to 1/8 inch in them, though you can hold smaller material, as well.
I don't know how precise you need to be, so I will add this caveat. I usually use a 4-jaw chuck, so I can indicate the material after installation and position it so it is as precisely centered as I need for my application. This may not be an issue for you, especially if you are turning wood, and an error of a few thousandths may be irrelevant.
If the diameter of the wood is known, (for example, if you plan to turn pen bodies that are 3/8 inch in diameter), you could take a larger diameter length of round metal stock, maybe one inch long, and drill it longitudinally for the outer diameter of your wood. Then place this in a vise, and use a hacksaw to make a slot lengthwise in the part. Clean up any burrs inside with a jeweler's file. Now you can slide your wood into the adapter part you just made, and chuck this into the existing 3-jaw chuck. Just make sure that the slot is between the jaws, and not under one of the jaws. Tightening the chuck will tighten the adapter and grip the wood.
I have a few of these adapters that I have made over the years to save me time when I don't want to be bothered changing to my collet chuck to make one or two small-diameter parts. They work pretty well, and I have held material down to 1/8 inch in them, though you can hold smaller material, as well.
I don't know how precise you need to be, so I will add this caveat. I usually use a 4-jaw chuck, so I can indicate the material after installation and position it so it is as precisely centered as I need for my application. This may not be an issue for you, especially if you are turning wood, and an error of a few thousandths may be irrelevant.
