Pneumatic Preload Ball Nuts

[coop2005]

Has anyone succesfully designed and or built a mechanism that uses compressed air to preload 2 ball nuts or any nuts for that matter. I was thinking about designing something like this for a router im building and it seems like it has many advantages. This would allow for easy setting and verification of the preload via a pressure gauge. In ideal circumstances with a large enough surface area and rigit pneumatic lines you may even be able to see small pressure fluctuations when the preload is insufficient for the task. Im an electrical engineer with a self taught mechanical background so maybe im out of line with this idea. Any thoughts, i think this is something i would like to try.

[Geof]

Perhaps you should do some calculations on the kind of piston area you would need for the preload force that would be needed. Compressed air systems rarely run much above 100 psi and you may find it difficult get enough preload force because you do not have much space for a decent sized piston and the piston would have to be annular as well.

I think it is potentially a good idea but it may be necessary to make it a pneumatic over hydraulic system with a pressure multiplying setup.

[S_J_H]

When I built my cnc bench lathe I thought about using mini nitrogen gas springs to preload the nuts. I ended up just using coil springs but the gas springs would have looked neat if nothing else.
http://www1.mscdirect.com/CGI/GSDRVS...00000036913957
Steve