Idle Question about Rotary Tables

I'm not going to buy one soon, but if I did:
Could I put a tool holder on a rotary table and use it for turning
spheres and spherical sections? Or is your average rotary table not
designed for such abuse?
Reply to
Tim Wescott
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In conjunction with a lathe? Unless it's really tiny or your lathe is bigger than most home shops have, the table height is going to be a problem with clearing the work. The principle is correct, just the means chosen isn't probably going to do the job. I suppose you could set it vertically on a mill table, chuck up your work somehow in the spindle and proceed that way. Far easier to make/buy a radius rig like this:
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There's any number of variations on the theme, it's a perennial project in the hobbiest mags, all would be cheaper and faster than a rotary table for ball and radius turning.
Reply to
On a lathe? That's an interesting idea!
No, too big. You either need a really big lathe or a really small RT.
Reply to
Nick Mueller
You can make spheres and spherical cavities by using a flycutter or boring head on a mill, with the workpiece held in a chuck mounted to a tilted rotary table.
See, e.g.,
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That's how I made the little spherical lamphouses. The collimator retaining collars pressed on to short necks left on the spheres.
This technique is documented in Guy Lautard's next Bedside Reader (TMBR4) if he ever publishes it. Email me if you'd like a copy of my article and promise not to distribute it further. It is copyrighted material.
Reply to
Don Foreman
It'll handle the loads just fine.
Now find a decent RT that will fit between the slide and the work. You run out of room real fast there.
Cheers Trevor Jones
Reply to
Trevor Jones
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One other trick is with a dividing head, which can be easily adjusted to angles other than horizontal or vertical. Mount a chuck on it, clamp the workpiece in the chuck, set it at an angle (45 degrees or so, depending on the needed diameter of the stem from the ball), put a boring head in the mill's spindle, with the tool bit oriented to cut on the inside instead of the outside, and then lower the spindle until the dividing head is cutting a circle in the angled stock. Then start cranking the dividing head. You may need to do multiple passes, starting with the dividing head cutting too high, and slowly working down to the proper height. I've seen this used to make the ball handle for a bolt-action rifle being modified to accept a 'scope.
Enjoy, DoN.
Reply to
DoN. Nichols

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