View Full Version : Endmill trims more via conventional cut

10-15-2012, 03:36 AM
So I was minding my own business, cutting a slot in Aluminum the other day. It's one of those times where you slowly make the slot a little bigger a bit at a time until something fits in. I noticed, when passing the endmill back and forth over one edge of the slot, that it would tend to trim more if it was a conventional cut vs climb cut. Why is that? I thought that a climb cut has better geometry for the cutting edge to dig in instead of rub. This was with a carbide endmill, by the way.

10-15-2012, 08:48 AM
Sounds to me like your gibs may be a little loose and the table is shifting in one direction more than in the other direction.


10-15-2012, 09:12 AM
If you were using a small diameter endmill it was most likely the endmill deflecting.Conventional milling defects the cutter in climb milling defects it out.

10-15-2012, 10:18 AM
cutting aluminum i always cut with faster spindle and climb for each pass . non climbing leaves a bad finish , chip marks and tends to clog up .

10-15-2012, 12:15 PM
I think with climb cutting, the tendency is to be "pushing" the stock away from the cutter ( 9 o'clock to 12 o'clock position) while conventional cutting "pulls" the work towards the cutter (12 o'clock to 3 o'clock position.) So any dullness in the cutter, or deflection of the bit, or slop in the machine ways is exaggerated one way or the other.