slideway support rails + oilite bearings

[colormecnc]

im in the uk and just getting started in this game. has anyone out there had any success with stainless round bar and oilite bearings as a means of support for the xyz axis. my idea is two bars with the leadscrew in the centre of them to drive each axis carriage/support. im figuring on 12 / 15mm bar over maybe 500mm . would the oilite bearings wear unduly? they appear to be cheap but would they last???
im thinking of making each axis from aluminum flat stock, approx 20mm thick,
with the vertical ends as the supports for the slideway bars and leadscrew

[Sweep]

Don't know if this will help?

I tried 2 x 20mm tube over 500mm with screw in between, using ptfe type bearings. The problems I encountered were:

The tolerance between bearing and tube had to be good otherwise the slop in the carriage on the rails could easily be felt.

The carriage would easily snag.


Even over 500mm the rails would sag with little weight on them.

Friction was high.

The solution for me was to go for the skate bearing approach, which I found to be far superior, they just glide.

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You might find it difficult to insure that the bearings are positioned accurately.

If the rails are likely to bend and its a problem in your application,then you will need to support them which will probably rule out a closed bearings.

If loads on carriages are low and you can set everything out accurately can't see wear being a problem.

If you suggest your application someone much smarter than me might be able to help.

All the best!




Just my opinion

[Al_The_Man]

Originally Posted by colormecnc im in the uk and just getting started in this game. has anyone out there had any success with stainless round bar and oilite bearings as a means of support for the xyz axis.

I am not sure if you can get these product in the UK but they have just about got the lube free linear slide ace'd.
The simplicity range of Pacific Bearing.
http://www.pacific-bearing.com/files...20Catalog1.pdf
Al.