Originally Posted by
momus_cnc
Oh no! The Version 1.0 carriage comes back to haunt us. Some others had this same issue and there are a couple of things you can do. The easiest (if you didn't already build it that way) is to replace the four 1/4" studs with 5/16" grade 8 bolts and torque them down as tightly as you can. I posted a thread on here at some point showing that upgrade. That greatly increases the clamping force and seems to have taken care of the problem for most.
There are a couple of more invasive solutions. One is to go with the new version 2.0 style carriage, which has roll pins to prevent racking. I also put a thread on here with drawings for the few parts that would need to be fabricated to install this on the old 1.x machine. Another solution is to do what Chris (OCNC) did, which is install a thin plate in the carriage that gives it diagonal shear resistance. There are also some drawings of that mod in a thread somewhere.
-Bob