First cut in aluminium. Disaster.

[Edward]

With my Sieg2.7 mill all cnc converted, I have been testing it with a few scrap pieces of Delrin, cutting pockets holes, etc, to fit various ballbearings.

This helped me get acquainted with Fusion360, using Adaptive clearing first, then finishing off with 2 passes of Contour, etc.

So far so good, perfect and smooth results and I was feeling quite smug:)

So this morning I tried aluminium for the first time, just a typical hole of 30.05mm on a 15mm thick scrap, like you would do to fit a ballbearing, so I could check accuracy and so on.

My feeds were 200mm/min and the adaptive cut was set to 2mm both for radial and plunge. 8mm endmill, at top 2000revs.


It all started very well......but then, as the endmill got close to the periphery of the 30mm circle, disaster struck. The whole thing jammed. Luckily I was there to press the e-stop and no major damage happened. I lifted the Z. The endmill had some aluminium welded to it, I tried to snap it off, but it is too welded, so goodbye endmill, it was nice while you lasted:) F&^%*

So next time I will be more conservative, maybe I will reduce the feed to around 150mm/min and the depth (both radial and axial) to around 0.4mm. I know this will be fine because I regularly use this when milling manually on another smaller mill. If successful, I will increase this depth as I gain experience, just to find the limits of the machine, which I reckon may be at around 1mm deep at 150mm/min or thereabouts. Trial and error.

Any advice?

Edward