Hey all,
I’m a 1st year apprentice fitter and turner in a factory that makes sheet metal parts. In down time we sharpen punch tooling and seeing if anyone could weigh in.
We sharpen these 30 square punches with relief angle on this jig that can rotate 180/90 degrees to do all sides but I always seem to get these rough finishes with waves and especially where the lines intersect. Also always seem to end up with these rolled edges on the end of all my tools.
I dress the wheel by like 0.05 before starting each tool if there’s a lot to take off and a couple of 0.02 dressing during sometimes, also always using coolant and taking passes of 2 microns when plunge cutting or 5 microns per pass when cutting regularly.
My tradesmen say the burr is fine as long as it’s sharp (fingernail test) and that the bumpy finish is just relief angle so it doesn’t matter but still wanna try and get them proper.
Any insight is appreciated.
Cheers