Here we go again . . . MK4

[routercnc]

Next part is the Z axis stepper motor bracket.

Laying it out:


Machining the pocket - no adaptive toolpaths I'm afraid so about 1 hour to machine this:


Then the slot for the motor shaft:


Small pocket to clear the boss on the front of the stepper:


Light skim to get a level surface:


Outer profile cut:

I had problems here as I had the tool stick when it was about 10mm into the part. It was on one of the curves (which I think increases the chip load a bit) and I had about 2 seconds to go from hearing the problem developing to the spindle stopping rotating. I cleared the tool and thought I'd got away with it but it had obviously missed some steps as there was a ridge in the part. I let it finish, going easier on the feedrate, then homed the machine and ran some new full depth toolpaths working up to about a 0.5mm offset inward. This made the outer surface 0.5mm smaller all round, but at least it was smooth again. For this part it did not matter so I was lucky.

Machining the bolt slots was pretty quick:


Set it on end and machined the clearance holes for mounting (thought this might vibrate but it was fine):


Skimmed the other side down to get the final 20mm thickness:



That will do !

OK, so it was not 20.00 everywhere . . . !


Counterbored to 9mm deep (DRO coming in handy here to get them to the same depth)


Snail countersink to finish off (love these things, so much better than the star type which are a waste of time):


Done. Worked out OK in the end: