I am new to CNC and have a new to me PCNC 770 Series 3 and am having trouble drilling a 1/2" thru hole about 2" deep in 6061 aluminum.
My approach is to spot drill the hole, then drill a full depth pilot hole with a 5/16" drill. The problem occurs with the next step of actual drilling of the 1/2" hole with a new HSS drill bit. The 1/2" drill bit either stalls the spindle motor or the Z axis won't push the drill through the material (and seems to keep trying and maybe losing steps until I hit the stop button).
The last attempt was at 990 rpm and feed of 3.75 ipm using a deep drilling cycle with full retract and .25" peck cycles. Both the spindle pulley and the PathPilot are set on the low belt speed range.
Any suggestions on speeds and feed that I should try?
I would also really like to get this operation done while in the high belt setting.