[keebler303]

I'll have to check the runout on my machine. I have broken plenty of endmills, but they have mostly been F-ups on my part, not just spontaneous breakage.

No offense but you did have the gearbox in high with the spindle going the correct direction right? I can't believe a .01" cut at 10 ipm would break your endmill, even with a little runout. The speeds I mentioned were for aluminum, what are you cutting? Are you plunging straight to depth or ramping in? Any coolant/lube?

Matt

[John Bennett]

Reading post, you are using a 1/16 endmill (you have not stated how many flutes) . I would presume that this is a HSS endmill. What material are you cutting and to what depth per pass? If you are using say a two flute endmill in 6061 aluminum, then you are about double what, I calculate, your feed should be. Give us all information to recheck your feed and speeds.

[John Bennett]

I agree with your feed if at 5000rpm, but you stated 2500rpm which for a 3 flute cutter would bring use into the range of 6ipm or start point of 5ipm.

[pyroboby]

Yeah, my brother in law works in the opposite end of the factory, he said 4 or 5 ipm. Ill be trying it later after I have a few more end mills. As I said I'm going to use a keyseat cutter for now. I wish I had the budget of my day job for home use for just one day.