What worked

triangular inserts . What worked was to lock the rotary table in position and using the end of the mill to do the cutting . Average depth
of cut was around .015" per pass , cranking slow in X . I first tried locking down both axes and advancing the RT one hole (in a 47 hole plate) at a time . That calculated out to about .003" feed per hole . Full depth cuts , and that didn't work so well . I didn't make a killin' on this , but learned a little more about machining hard materials . I gotta say , I felt very pessimistic about this whole thing when an M42 end mill just skated on the part . Delivered them today and found out it took 20 years to cause the damage , this should give him 20 more - and this was their only option , parts are no longer available .
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Next time you need to machine hardened material try ceramic inserts. They will cut material that carbide won't scratch.
Best Regards Tom.
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On 6/5/2018 4:59 PM, Howard Beel wrote:


of a hobby . Occasionally someone calls me and says "Can you ..." and I'll usually say sure , I can try !
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On Tuesday, June 5, 2018 at 4:20:35 PM UTC-4, Terry Coombs wrote:

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On 6/6/2018 6:35 AM, snipped-for-privacy@krl.org wrote:


So which triangular inserts does your home made mill take? I have a couple of store bought end mills that use triangular inserts, but also have some triangular inserts that are the wrong size and are not worth anything to me. The local scrap yard sometimes gets a bunch of carbide inserts when someone is cleaning out their shelves.
Dan --------
I was wrong the other day , my tool takes TNMG inserts , I currently have TNMG 321's and 322's in both C2 and C5 . I bought 5 of each at least 10 years ago , have a couple of each still left . I don't use carbide much ...
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