tgford58
Plastic
- Joined
- Nov 10, 2010
- Location
- Indiana USA
I’ve hit a pretty consistent problem. Drilling 6061-T6 with parabolic drills I get oversized holes if I’m anywhere close to manufacturers speed and feed. Today is an example; .3438(11/32) Guhring parabolic, bright. Drilling .75 deep. Small spot using 3/8 140deg spot. Manufacturers data was .01 per rev SFM 260. First hole was .361 and tapered to the bottom. Second hole ran at .005 per rev was .354. Changed spot to full depth. At .005 feed hole was .348. At .002 per rev hole was right on with .343 slip loose. .344 no-go.
i have this issue with most parabolic drills over .25. What am I missing?
Thank you for any help.
i have this issue with most parabolic drills over .25. What am I missing?
Thank you for any help.