Re: Concept Design for a new 6-axis router - take your best shot!
Originally Posted by
awerby
It would, I'm afraid - thanks for checking that. The gantry probably will weigh about 250 lbs with the Z axis, heavy ball screw, spindle and the 5th/6th axis assemblies. But don't I get to divide the weight by two, since it's supported on two sides? I suppose when all that stuff moves to one side or another, it starts weighing a lot more on that side, though. Fortunately, I haven't ordered the steel yet. What if I went up to 4"x 10" - would that improve things significantly?
With your non-standard beam end conditions it is probably time to do some simplified FEA if you have that capability. Your 10 foot 4x8 beams weigh 275 lbs each. Making them taller definitely helps (by the cube of the height). But also linearly heavier. Maybe diagonal braces or a middle set of leg stands would be better. Decide what deflection (sag) you can stand and build the lightest structure that gives you that.
John C
carpenterswoodworking.com