Lead screws for ever...

Or at least the threads on leadscrews may go on forever...

I thought I might throw my two bits in the hat as well, I've uploaded a drawing of the mounts I'll be using for router. I sent this drawing along with full parts drawings to a chap up north and he made up two and said they work OK. I'm using a standard SKF axial bearing, about $20 each here, so probably half that in the US.

The drawing is called chris_lead_mount.gif.

The copper washer is annealed before preloading the thing up. The bearing retention plates are turned on a lathe out of 10mm billet and then faced off after making the bearing "flange" to give roughly .05mm preload on the bearings. The retention nut on the end of the screw is then wound up to hold the whole package together, and backs the preload off to about .03mm or so.

A keyway was added for the pulley by the chap who built one. If he did up the nut tight enough to hold the pulley the preload was lost on his setup, but I don't think I'll have that problem with mine. (Lower torque requirements) I may use a pulley with an integral collet and grub screws, or do something else cunning, as milling into a SS shaft is not something I have the gear for.

Cheers, Chris.

* Design engineer, Assembly worker, Cleaner.
* Ohmark Electronics. PO Box 5302, Christchurch, New Zealand.
* http://www.ohmark.co.nz




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