I am having a problem with pencil milling on my CNC router. I got this groove pencil milling the pattern with a 1/4" carbide ball mill with 2" sticking out I stopped the machine before it carried on taking it lower all the way to the corner. This morning I have been delving into finding the problem, my first thought was the z offset. I triple checked this and that is not the problem.
I checked the runout at the tip of the cutter and it was out by about .004 one side to the other. I though I had found my problem, so I changed the collet and tried cutting again. The groove was much less but is still about .008-.010 deep. I checked the runout and it was .001 from one side to the other which means it is .0005 off center. 1 thou deeper would be acceptable but an .008" deep step is unacceptable. Could the .0005' runout be causing a .008" deep groove? The cutter is running at 24000rpm and I tried dropping it to 12000 to see if that would make a difference but it did not.
My only other though was it was a software issue but I am starting to discount that option.
I checked the runout at the tip of the cutter and it was out by about .004 one side to the other. I though I had found my problem, so I changed the collet and tried cutting again. The groove was much less but is still about .008-.010 deep. I checked the runout and it was .001 from one side to the other which means it is .0005 off center. 1 thou deeper would be acceptable but an .008" deep step is unacceptable. Could the .0005' runout be causing a .008" deep groove? The cutter is running at 24000rpm and I tried dropping it to 12000 to see if that would make a difference but it did not.
My only other though was it was a software issue but I am starting to discount that option.