Quote Originally Posted by njhussey View Post
Depends on the size of the pulleys I guess, I've used M4's on the 20 tooth pulleys as well as the 40 tooth ones. My 40mm pulleys are a push fit on the ballscrews so I'm hoping that's enough. Could always put a bit of loctite on too...
Larger grub screws the better so can get good purchase on them, fiddley Grub screws are a pain and definately loctite the pulleys on. You'll never really want them off again other than to replace and certainly don't want them spinning on the shaft. Also mark them so for easy visual reference so can check they are not spinning.