I had just finished sharpening my largest end mill (20mm) and while taking a test cut across a 12mm square piece of MS I noticed that as the cutter passed across the face of the work in the X plane the trailing edge of the cutter was also taking a cut, this is something I had observed many times before but never given it any thought. Why should it do that ? even if I had made some sort error in the sharpening process surely once the leading edge of the cutter had passed over the work the trailing edge would have nothing to cut - unless the trailing edge was lower than the leading edge.

I was moving the table from right to left so this meant the mill head must be tilted slightly in a clockwise direction. I checked the degree scale at the point where the mill head tilts and it looked to be set on 0deg - my mill an Arboga has a tapered pin that locates the head in the 0deg position, loosening the lock lever I found I could rock the head ever so slightly, even though the pin felt tight I kept tapping it with a plastic mallet until I could feel no more movement in the head.

A quick check by taking a cut confirmed that the head was now much closer to being perpendicular to the table (possibly even perfect) - no matter which direction the feed was in R-L or L-R the trailing edge was no longer taking a cut, this is something I'll have to be aware of in the future. If this something you notice in your own setup maybe it is time to check the vertical alignment of the head.


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