Re: Spindle-turning Long, Thin Wood: Update...

Ali T. Borahan wrote: (clip) Does it really matter if the contact point is the tangent line that's exactly perpendicular to the center of the arm? (clip) ^^^^^^^^^^^^^^ It matters not at all! The design I described in an earlier post takes this to an extreme. Instead of slots, I mount the arm through a drilled hole, with a clamping bolt. I get the distance from the centerline by swinging the arms away from center--the action the guides would prevent. I have built two steadies this way, both used on large lathes, and they work just fine.

Long before the work has a chance to start whipping, you would notice a little looseness at the wheels, and correct it. If the bolts are tight, and the work is round, that is sufficient.

Reply to
Leo Lichtman
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JOECOMUNALE wrote: (clip). like what if that piece starts to wobble? Then - you had better have some sturdy reinforcements (clip) ^^^^^^^^^^^^^ I see the mental image that's worrying you, but don't think it's gonna happen. First, I would never rely on a steadyrest to stabilize an unbalanced piece. If the piece is in balance, and the CG is on axis, there are no forces to start the vibration. Without a steadyrest, a rotating piece can get very slightly off center, generating centrifugal force, which draws it farther off center, increasing the centrifugal force, and things run away. If the steadyrest is doing its job, doesn't ever start to get off center. And, if a tiny does occur, the wheels prevent the displacement which leads to the runaway reaction.

I have had the wheels run very slightly loose, due to my own carelessness, but have never had even a hint of a disaster.

Reply to
Leo Lichtman

Hi Jim.

I know it'll be heavy. My calculations actually bring it to about 75 lb (I'll be using mild steel, which isn't so dense). Of course, this all depends on whether or not I can find a free source. I think I've found the source, now I'm just waiting for the actual donation. Alternatively, I do have a 1/2" X 1' X 1' piece of aluminum available, but I hate to waste that. I'd also rather the platform were heavier than lighter. I'll be standing on the thing (and I weigh around 200 lb, all muscle... YEAH RIGHT!!! I wish

of 2 1/2" plumbers pipe) be rigid. For that, I think I'll need some side struts or something. Anyway, when I'm done with the whole design, I'll let ya'll know how it worked out...

-- Ali T. Borahan AliSails - Fine Wood Artistry & Custom Woodcrafts Web URL:

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PS: A last resort/solution would be to use engine flywheels. They weight about 40 lbs and I can get any number of them that I need (I work at Volvo Penta during the day :) to build a tower of sorts. Put the post/pipe in the flywheel hole (center), and voila, I've got a nice, stable--and easily movable, platform.

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Reply to
Ali T. Borahan

You could probably also fill that pipe with sand or concrete to add weight, increase rigidity and dampen vibration.

Reply to
Woodpecker

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