External turning with a boring head

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Mr Ron
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Re: External turning with a boring head

Post by Mr Ron »

warmstrong1955 wrote: Thu Feb 08, 2018 12:32 pm Is 3" too long due to the size of your mill? I have RH bars from 3" to 8", which I have used vertically, for ID's of course.
If you are turning the OD, the machine will need to be turning forward if you use a LH bar.

Bill
I'm thinking a 3" long bar would not be rigid enough used vertically. My mill is big enough
Mr.Ron from South Mississippi
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warmstrong1955
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Re: External turning with a boring head

Post by warmstrong1955 »

Mr Ron wrote: Fri Feb 09, 2018 3:23 pm
warmstrong1955 wrote: Thu Feb 08, 2018 12:32 pm Is 3" too long due to the size of your mill? I have RH bars from 3" to 8", which I have used vertically, for ID's of course.
If you are turning the OD, the machine will need to be turning forward if you use a LH bar.

Bill
I'm thinking a 3" long bar would not be rigid enough used vertically. My mill is big enough
I use 'em, and a lot longer than 3". If it will work to bore in a lathe, it will work to bore in a boring head on the mill no? A boring head probably is not as rigid as a lathe tool post....but it will work.
I've bored things on my mill, that would been a lot easier in my lathe, but no way did I have the swing.
It's a matter of the depth of cut when you get out hangin' there, and some testing to see where and how deep you can go. I did some bores, 1-1/2" diameter to begin with, and 6-3/4" deep. I used my 2" boring head, and a 1/2" x 8" bar. Ideal? Probably not....but it sure worked, and quite nicely after I played around with it! And for about 50 parts. Boring was easy. Set up....I built a fixture after the first one, cause it was a pain in the something without it.

And....!!!
If you are looking for a bar to turn the OD, make sure you look at a regular LH boring bar, not the one they sell for the horizontal hole in the head. The insert is positioned incorrectly on the horizontal bar, if you are after any vertical bore, ID or OD.

Hope I made sense....

:)
Bill
Today's solutions are tomorrow's problems.
Richard_W
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Location: Molalla, Oregon

Re: External turning with a boring head

Post by Richard_W »

I find that heavy metal or solid carbide works best in the 2" boring head. I still had to slow down for a solid carbide bar hanging out 4". But a solid carbide bar hanging out 2 1/2" I could run at 1100 RPM if the boring head wasn't off set to far. This was done on a Bridgeport clone mill.
Mr Ron
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Re: External turning with a boring head

Post by Mr Ron »

Thank you all for the input. Although I rarely need to turn outside diameters on the mill, at least now I have the answer for next time.
Mr.Ron from South Mississippi
Richard_W
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Joined: Fri Jan 10, 2003 1:00 am
Location: Molalla, Oregon

Re: External turning with a boring head

Post by Richard_W »

warmstrong1955 wrote: Fri Feb 09, 2018 3:49 pm And....!!!
If you are looking for a bar to turn the OD, make sure you look at a regular LH boring bar, not the one they sell for the horizontal hole in the head. The insert is positioned incorrectly on the horizontal bar, if you are after any vertical bore, ID or OD.

Hope I made sense....

:)
Bill
If you get a left hand bar that uses the CCMT215x insert, it will turn an O.D. as well as bore in the cross hole in the forward direction.

Richard W.
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