Quote Originally Posted by JAZZCNC View Post
Honest truth is your machine can not run this cutter correctly without compromising wear and finish. You'd have been better buying more of cheap HSS as they'd be cutting more like correct so will probably last longer and give better finish. Carbide doesn't like being run incorrectly and will wear fast if not.

But to answer your question then a very very rough ball park figure would be find the correct feed n speed. Divide the feed by your max feed then divide the speed by this number. ie 7500mm/min 21,000rpm would equal 7500/2000=3.75 21000/3.75=5600rpm

But again this is very rough ball park figures and trail n error will be needed.

Thanks Jazz,
I've tried it on 8000rpm this afternoon, the chipload looked alot better than when I used the twin straight flute cutter but also I was running that at 18000 rpm ! temperature of the spiral was low. I expect though any new ultra sharp cutter would give a good finish but I'll try lower speeds tomorrow plus swap the toolpath settings to climb rather than conventional so it pulls the work towards the fence.

Your help is much appreciated, thanks again