I have the Grizzly mini mill and I am currently CNC retrofitting it. It is the same one Harbor Freight has except it is green. I am going put my z-axis lead screw in between the pinion gear and the motor that is on top. I want to drill a hole completely through the head of the mill. My question is how much room do I have between the pinion gear that pulls the head up and down and the gear box. The screw is 3/4. I don’t want to drill into any thing important. I pulled the pinion gear out to make sure I could clear it but I am not sure if I am going to hit any thing important on the motor side.

Well, you can ditch the rack and pinion, that way you will free up a ton of space.

If you take the head apart, put the back half in a mill and make that groove deeper, you should be able to get plenty of space for it.

You might also consider a slightly smaller screw to make it fit better(5/8 or 1/2")


Jon

I am looking at a raw spindle mount casting as I write this. from the centerline of the pinion shaft to the front of the casting is @2.5". It is all open space in there. You have a good 1.4" about the centerline of the casting before you break into the bosses for the mounting bolts. Drill away!!

Ken
KDN Tool