Thread: How do you build telescopes/forklifts?
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Unread 05-12-2010, 12:19
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Re: How do you build telescopes/forklifts?
We've tried the 80/20 extrusion and Delrin sliders as well, but did not like the binding. That is why we went with draw slides.

With the extrusion/slider set up you typically need two sliders on each 'post' for stability. To minimize binding you want to keep the sliders as far apart as possible. This usually means mounting one slider at the top of the lower lift member and the bottom of the higher lift member. As the lift is extended, the slider on the upper member moves with it and gets closer to the the slider mounted on the lower member. Some experimentation can determine just how close the two sliders can approach without bind. You can then put in stops.

A general rule of thumb is bearing surfaces should be separated (lengthwise) about 3 times their diameter (or width). My experience suggests this may be a little close for 80/20 hardware so you may need 4 or 6 times the width. (For a 1" extrusion this means 4 to 6 inches between the slider pairs.)

One last though on bind: Aluminum is actually have fairly 'sticky' material. Can you substitute another material or cover the aluminum (plating, enamel, powder coat)? Dry lube sprays may also help.