The machine shop prof. at the university used to say that if you get chatter, try a slower speed and a faster feed. If Saturn is up and Mars is in Virgo, that works. Sometimes.
Best cutoff tool profile?
- Greg_Lewis
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Re: Best cutoff tool profile?
The machine shop prof. at the university used to say that if you get chatter, try a slower speed and a faster feed. If Saturn is up and Mars is in Virgo, that works. Sometimes.
Greg Lewis, Prop.
Eyeball Engineering — Home of the dull toolbit.
Our motto: "That looks about right."
Celebrating 35 years of turning perfectly good metal into bits of useless scrap.
Eyeball Engineering — Home of the dull toolbit.
Our motto: "That looks about right."
Celebrating 35 years of turning perfectly good metal into bits of useless scrap.
- Greg_Lewis
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Re: Best cutoff tool profile?
By the way, I found this on the net:
Greg Lewis, Prop.
Eyeball Engineering — Home of the dull toolbit.
Our motto: "That looks about right."
Celebrating 35 years of turning perfectly good metal into bits of useless scrap.
Eyeball Engineering — Home of the dull toolbit.
Our motto: "That looks about right."
Celebrating 35 years of turning perfectly good metal into bits of useless scrap.
Re: Best cutoff tool profile?
My 12" Atlas does the same thing in spite of tightening every bolt in the lathe and base, and the leg pads are glued to a cement floor. I have made sure the spindle bearings are tight. I have done what I can with the attachment of the drive pulley to the headstock gear, but there is still a bit of slop after 65 years. I don't understand how it flexes that much in such a short distance.by Greg_Lewis » Mon Dec 05, 2022 12:01 am
Yes, rigidity counts for a lot. If you've followed my posts over the years you might remember that my lathe is an Atlas/Craftsman 12, which I have dubbed "the flexible flyer." Even though it's on a metal stand made from heavy welded angle iron and 1/2 inch plate top, I can put a DTI in the toolpost and its tip against the chuck and watch the dial move when I push on the headstock. I have determined that it will chatter depending on the alignment of the planets and phase of the moon.
Chatter city if I don't have the speed set right. I have finally come up with a cutoff method that helps. I run the tool in about 2x the width, back out, move over 1/4 width, run the tool in about 2x the width deeper than the first, back out, move the tool to the original position, etc. until the parting is complete.
Oh and I agree with the HSS cutoff blade, and the one I use is tapered top to bottom.
--earlgo
Before you do anything, you must do something else first. - Washington's principle.
- Bill Shields
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Re: Best cutoff tool profile?
that appears to be what I used = T at the top, i don't care about the bottom....Greg_Lewis wrote: ↑Mon Dec 05, 2022 8:28 am By the way, I found this on the net:
2000-6010d92019.jpg
Too many things going on to bother listing them.
- Greg_Lewis
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Re: Best cutoff tool profile?
Nice to know that I'm not the only one.
Greg Lewis, Prop.
Eyeball Engineering — Home of the dull toolbit.
Our motto: "That looks about right."
Celebrating 35 years of turning perfectly good metal into bits of useless scrap.
Eyeball Engineering — Home of the dull toolbit.
Our motto: "That looks about right."
Celebrating 35 years of turning perfectly good metal into bits of useless scrap.
- tornitore45
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- Location: USA Texas, Austin
Re: Best cutoff tool profile?
Purchased parting tool: Use T a grind a longitudinal v or u grove on the top.
Home ground: T is impractical taper just enough. All is needed is to keep from rubbing the sides, too much taper and you have a weak tool.
Home ground: T is impractical taper just enough. All is needed is to keep from rubbing the sides, too much taper and you have a weak tool.
Mauro Gaetano
in Austin TX
in Austin TX
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Re: Best cutoff tool profile?
have to be careful fellows !
Lots of Chinese tooling out there that is wrong.
here is a few shots to show you bad, and good .
Enco sent me new "Good" tools aft I showed them the pics.
So last week I was at our Tech College---and guess what, they have the bad version of the tools
Rich
Lots of Chinese tooling out there that is wrong.
here is a few shots to show you bad, and good .
Enco sent me new "Good" tools aft I showed them the pics.
So last week I was at our Tech College---and guess what, they have the bad version of the tools
Rich
- Greg_Lewis
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Re: Best cutoff tool profile?
Interesting, Rich. I got burned by Enco (and some appalling treatment by the personnel) many years ago and didn't go back. I thought MSC bought them out and shut them down.
Greg Lewis, Prop.
Eyeball Engineering — Home of the dull toolbit.
Our motto: "That looks about right."
Celebrating 35 years of turning perfectly good metal into bits of useless scrap.
Eyeball Engineering — Home of the dull toolbit.
Our motto: "That looks about right."
Celebrating 35 years of turning perfectly good metal into bits of useless scrap.
-
- Posts: 1761
- Joined: Sat Dec 21, 2002 12:16 am
- Location: Green Bay Wisconsin USA
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Re: Best cutoff tool profile?
I posted this before on a Parting Tool Thread to help those who have
issues with parting. You also should look at Power feed when parting as most crashes occur when the handle is turned from
The one o'clock position to the four-five o'clock position due to sudden downward force ( uneven feed )
here is what can be done to help
Rich
issues with parting. You also should look at Power feed when parting as most crashes occur when the handle is turned from
The one o'clock position to the four-five o'clock position due to sudden downward force ( uneven feed )
here is what can be done to help
Rich
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Re: Best cutoff tool profile?
yes Greg, those straight sides are murder, they create heat and scuffing and yet still being used I guess.Greg_Lewis wrote: ↑Mon Dec 05, 2022 8:15 pm Interesting, Rich. I got burned by Enco (and some appalling treatment by the personnel) many years ago and didn't go back. I thought MSC bought them out and shut them down.
Wonder if MSC has the inventory too ?
Rich
- Greg_Lewis
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Re: Best cutoff tool profile?
AH HA! Excess overhang. Never thought about that. Something to pay attention to. Thanks, Rich.
Greg Lewis, Prop.
Eyeball Engineering — Home of the dull toolbit.
Our motto: "That looks about right."
Celebrating 35 years of turning perfectly good metal into bits of useless scrap.
Eyeball Engineering — Home of the dull toolbit.
Our motto: "That looks about right."
Celebrating 35 years of turning perfectly good metal into bits of useless scrap.
- Bill Shields
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Re: Best cutoff tool profile?
I actually have 4 cut off tool holders, each with a different width of blade, set at different hangouts so that I can just grab and go.
One I have with the tip ground non parallel to the centerline so that it cuts off and leaves minimal nub.
You can never have too many tool holders.
Amen on the oddball cross section shapes.
You can also get into trouble it you get the blade mounted non-vertical.
I lay the holder on its side, then put an adjustable parallel up under the small section of the T to get it square with the holder...
All this is assuming that the small section of the T is not tapered.
One I have with the tip ground non parallel to the centerline so that it cuts off and leaves minimal nub.
You can never have too many tool holders.
Amen on the oddball cross section shapes.
You can also get into trouble it you get the blade mounted non-vertical.
I lay the holder on its side, then put an adjustable parallel up under the small section of the T to get it square with the holder...
All this is assuming that the small section of the T is not tapered.
Too many things going on to bother listing them.