Thinking of ways to reduce weight off the gantry I thought a small hydraulic motor could be used as a spindle. A quick search found one such as this: http://www.anchorlamina.com/p_hydrmotors.html Plenty of horse power in a small package. Looks like its bearings would take some load and they would be constantly lubed too. Shouldnt be too hard to DIY either. Would need a small pump too mounted off the gantry of couse. Thoughts?