Â* I ended up using my one homemade indexable end mill , only took 2
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 .

--
Snag
Yes , I'm old
and crochety .
Get off my lawn !

"Terry Coombs" wrote in message
news
I ended up using my one homemade indexable end mill , only took 2
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 .

--
Snag
Yes , I'm old
and crochety .
Get off my lawn !


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:

"Terry Coombs" wrote in message
news
I ended up using my one homemade indexable end mill , only took 2
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 .

--
Â*Snag
Yes , I'm old
and crochety .
Get off my lawn !


Next time you need to machine hardened material try ceramic
inserts. They will cut material that carbide won't scratch.

Best Regards
Tom.

---

Â* Thanks for the tip , Tom . This isn't really a business for me , more
of a hobby . Occasionally someone calls me and says "Can you ..." and
I'll usually say sure , I can try !


--
Snag
Yes , I'm old
and crochety .
Get off my lawn !

On Tuesday, June 5, 2018 at 4:20:35 PM UTC-4, Terry Coombs wrote:
Â* I ended up using my one homemade indexable end mill , only took 2
triangular inserts . What worked was to lock the rotary table in
position and using the end of the mill to do the cutting
--
Snag
Yes , I'm old
and crochety .
Get off my lawn !

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

On 6/6/2018 6:35 AM, wrote:
On Tuesday, June 5, 2018 at 4:20:35 PM UTC-4, Terry Coombs wrote:
Â* I ended up using my one homemade indexable end mill , only took 2
triangular inserts . What worked was to lock the rotary table in
position and using the end of the mill to do the cutting

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 ...

--
Snag
Yes , I'm old
and crochety .
Get off my lawn !