Havent posted in a while, and thought I would share a few thoughts for those that use this thread for ideas during their own build.
Couple of problems I found, related to the CNCFusion kit.
ZAxis pulley slips on ballscrew When I first built my machine I installed the kit but had to wait on the ZAxis pulleys so I bought some different pulleys. I used these pulleys until I got my replacements from CNCFusion. I found that the pulleys slipped on the ZAxis ballscrew quite a bit. I had to tighten them down about every other day (and I mean tight!) to keep them from slipping. I thought this was a problem with my pulley selection. After getting the new ones from CNCFusion I didnt replace the pulleys until I had also replaced the motors and controller (for a completely different reason) with motors that have much better power and torque curves. After replacing the motors and the pulleys the slipping got worse. One thing that I didnt do when I built the machine was install the gas strut. Didnt think I needed to cause my motor had plenty of power to overcome the weight of the head. But, the slipping made me start thinking that maybe the strut might help. I installed it, torqued the crap out of the pulley set screws, and bingo. No more slipping. This fixed the problem, but I really think that the way to fix this one is to have CNCFusion mill a flat spot on the ballscrew where the pulley mounts. That way there would be a better spot for the set screws to grab. I would do it, but I dont feel like pulling it off, and the slipping for the time being is gone. Moral of the story, make sure you install the gas strut!
Zero Backlash Motor Couplers I'd be interested to hear if anyone else has had this problem, but I have problems with the CNCFusion supplied Y and X axis couplers slipping on the ballscrews. First of all, these couplers are kinda on the small side, and only grab the ballscrew by a single clamp / screw on the coupler. With the motors I am using, this doesnt apply enough friction to keep the coupler from slipping. Even though I stripped the set screws out multiple times tightening them up. I believe that I have solved this by using these couplers; Zero Backlash Helical Shaft Coupler | CNCRouterParts The problem with these couplers was that I had to turn down a sleeve on the lathe to go in the end that was pre-drilled at 1/2" to fit my motor. It worked a lot better because in addition to the clamp / screw friction mount, it also has a fixed set screw on the side providing 2 points of pressure. Again, I think that on both the X and Y axis ball screws, CNCFusion should mill a flat side to allow the 2nd set screw to have a better seat.
Its all working now, but I thought I'd post these issues in case anyone else was scratching their heads with the same problems.
Scott...