The Shapeoko Forum

Hey guys! I'm relatively new to CNC and I'm having issues with my 1/4" upcut endmill pulling out of the collet and down and into my workpiece. I'm running 60 ipm, 1/8" depth of cut, and the carbide compact router set to a speed of just under "4". It happens when cutting a straight slot, 1/4" wide and all the way through my .67" piece of pine wood (in 1/8" steps). I thought that it might be a worn collet or a dull end mill, but I replaced both and am having the same problem with both of them brand new.

Any ideas what might be happening here?

Many thanks in advance.

are you sure it is a 1/4" endmill and not 6mm? Just doublecheck, it might be the reason your collet is losing its grip. Another solution, replace your collet. Collet's should be replaced over time. Hope this helps.