I am looking at building a router along the lines of what FandZ built in this thread:
http://www.cnczone.com/forums/showthread.php?t=71949
I am planning to make my unit a little bit larger, but I am trying to figure out if the unsupported rails are going to experience too much deflection. But first, I have to determine how much is too much. Can anyone give me some guidelines for this?
I have used Beam Boy to calculate the deflection of various thicknesses of 1" square steel tube assuming a gantry that weighs 80lbs and puts 40lbs on each of the two four feet rails.
.049 thickness = .0273 deflection at center
.065 thickness = .0216 deflection at center
.083 thickness = .0179 deflection at center
.120 thickness = .0138 deflection at center
Are any of these numbers sufficient? .0138 would work out to be less than 1/64th of an inch and I don't think my tape measures go that small.
Any input would be appreciated.