Quick question… I’m designing the bearing plates for our lift, and for the bearings that will run up the sides, how much spacing do I want to leave between the bearing and the 2x1?
That depends on a lot of factors. Primarily, how accurate your machining process is and how much slop in the system is acceptable. You don’t want to over constrain the bearing interface on the lift (for example, if you design your bearings to be exactly 2.000" between the outer races and you have a tube that is actually 2.005" wide).
Our elevator ran with a fairly loose setup last year; there was a reasonable gap between the bearing surface and aluminum tube. This worked well for our layout and the amount of overlap between elevator stages. I’d recommend between 0.020" and 0.050" of gap based on our mechanism from last year.
How are you manufacturering the plates? The DXF that we brought to the waterjetter had the bearings 2.010" apart. Using that with the 1/16" wall tubing sold by WCP worked great. We never actually measured what the spacing came out to or what the tube measured.
We are getting the plates and 2x1 machined by a reputable shop so tolerances are not the largest concern. We are using .875 od bearings, and I am thinking about putting them 1/64" (.015625) from each side of the frame, which I really don’t know if that’s the right distance or not.