Best cutoff tool profile?

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Greg_Lewis
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Re: Best cutoff tool profile?

Post by Greg_Lewis »

Bill Shields wrote: Mon Dec 05, 2022 9:09 pm ....
You can never have too many tool holders.
Ain't that the truth.


Bill Shields wrote: Mon Dec 05, 2022 9:09 pm 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.
My toolpost system is the Omni-Post d.i.y from KRF. The holders are easily made from flat bar and work well. So I will make another holder to fit the blade I get.
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.
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Greg_Lewis
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Re: Best cutoff tool profile?

Post by Greg_Lewis »

Here's an interesting holder. I always thought a cutoff blade should be fed in straight, no rake, but this clearly shows it at an angle with some back rake. What do you think about that?

tool holder.jpg
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.
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Bill Shields
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Re: Best cutoff tool profile?

Post by Bill Shields »

Is what I use. You can always touch off the top of the blade if you do not want the back rake....another reason to T

I have been thinking about putting a set screw in from the back to align the blade vertical, but never gotten around to it.

Another reason to stick with a blade size and style.
Too many things going on to bother listing them.
SteveM
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Re: Best cutoff tool profile?

Post by SteveM »

I have an AXA cutoff toolholder that has the blade horizontal.

Bought it off a retired machinist who had made it.

I grind the top of the blade with a little rake to compensate for not having the tool at an angle.

The advantage is that if I have to part, then move the cutter in for a deeper pass, I don't have to re-adjust the height.

And I also had an Atlas and can attest to the flexibility. You could actually see the toolpost move.

Steve
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Greg_Lewis
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Re: Best cutoff tool profile?

Post by Greg_Lewis »

As to rigidity, I just remembered that I have, but rarely use, one of those MLA rear-mounting toolposts. For those who aren't familiar with that, it's a hunk of cast iron that bolts to the cross slide and stands behind the work and into which you insert your tool upside down. Far more rigid than the compound. Also, I was looking around on the net and was reminded that it's best to sharpen the cutoff tool before every use to be sure it's dead sharp. I've been guilty of not doing this.
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.
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Bill Shields
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Re: Best cutoff tool profile?

Post by Bill Shields »

Just be sure you do not have a screw on chuck without a way of locking it
Too many things going on to bother listing them.
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Harold_V
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Re: Best cutoff tool profile?

Post by Harold_V »

Bill Shields wrote: Tue Dec 06, 2022 1:40 am Just be sure you do not have a screw on chuck without a way of locking it
Doesn't matter. The tool mounts upside down, so direction of rotation of the spindle doesn't change.

H
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Bill Shields
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Re: Best cutoff tool profile?

Post by Bill Shields »

Actually, the one that I have has the part running CW to cut off. Keeps the cross slide in compression.
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Greg_Lewis
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Re: Best cutoff tool profile?

Post by Greg_Lewis »

The Atlas is a 1 1/2 - 8 spindle and I never run it in reverse. Just too risky. The MLA toolpost is set up for the toolbit to be upside down. It works well but I rarely use it.
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.
SteveM
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Re: Best cutoff tool profile?

Post by SteveM »

There is an original Atlas "production" cross slide with slots on it that holds a 4-way toolpost in the front and a toolpost in the rear which can be used for cutoff.

They called it a "carriage turret".
AtlasCarriageTurret.jpg
It also has adjustable stops for both in and out travel.

I have one which I will be selling once I can get all my crap unloaded from the storage room.

Steve
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Greg_Lewis
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Re: Best cutoff tool profile?

Post by Greg_Lewis »

That looks like a nice item, Steve.

Here's the MLA cross slide and rear toolpost. For those of you who don't know about these, they come as raw castings that you machine as necessary. (http://mlatoolbox.com/index.html)

I haven't used the rear post much — no particular reason other than the d.i.y. toolpost that was designed by an outfit called KRF is so quick and easy to use. That was from plans advertised years ago in the HSM magazine, but you don't really need the plans if you have a couple of photos.

IMG_0574.JPG

IMG_0573.JPG
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.
earlgo
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Re: Best cutoff tool profile?

Post by earlgo »

Hey Greg, you stole my home-built tool holder!!
tool post with square head bolts.jpg
:lol:
--earlgo
Before you do anything, you must do something else first. - Washington's principle.
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