# Negative rake tool holder for PM lathe?



## maker of things (Oct 18, 2014)

Do you guys think MCLN type negative rake tool holders would work ok on my PM1440?  Specifically is it rigid enough to handle negative rake.  MCLN is an end/side cutting holder for CNMG inserts.


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## darkzero (Oct 19, 2014)

Yes, absolutely. I use MCLN turning holders with my PM1236 & my 1" boring bar is also MCLN. I mostly use CNGG inserts though but I do also use CNMG 431 & 432.


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## maker of things (Oct 19, 2014)

That's a satisfying looking pile of chips!  Thanks Will.


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## Karl_T (Oct 19, 2014)

I use CNMG negative rake inserts and tool holders a great deal on my 10EE. With many inserts chip breaking is a big problem - get piles of swarf wrapped around everything. The 10EE just can't run high enough feeds and DOC to chip break. But you can remove material FAR more rapidly than any other method. 

I've found inserts designed for AL actually work quite well for finer cuts I commonly use. If you look at them carefully, they actual have positive rake right at the cutting edge. These inserts chip easily on steel so they often don't last long this way.

I got a PILE of CNMG inserts at an auction years ago.


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## wrmiller (Oct 19, 2014)

This is all good info guys!

The next big purchase will be a 12x36 or 13x40.  )


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## tmarks11 (Oct 19, 2014)

maker of things said:


> Do you guys think MCLN type negative rake tool holders would work ok on my PM1440?  Specifically is it rigid enough to handle negative rake.  MCLN is an end/side cutting holder for CNMG inserts.


No question about it, should work just fine.  MCLN/CNMG is the tool holder and inserts that I use on my G0709 14x40, which is very similar to your machine (PM1440).

Note you can get tool holders that make use of the unused 110 degree corner: MCKN.

Now if you want to cut aluminum, I suggest you look for something different.  Something with a 7 degree positive rake insert like CCMT or CCGT, no coating, nice sharp ground edge. Downside of this is they are single sided, so you only get the two corners out of 80 degree diamond insert, and they won't fit into your MCLN tool holder (you need SCLC tool holders).

Or stick with HSS for aluminum (or AR Warner HSS inserts if you want to go the insert route).


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## Rbeckett (Oct 19, 2014)

If you have a QCTP why not just mill the tool holder to met your needs.  You could give it as much or as little negative rake as you would care for and then you would not have to buy special bits and tool holders.  Just get a block of Alli use a straight 2 flute mill to hog out the main groove and a 60 degree vee cutter from LMS for that size dovetail.  Easy peasey Japonesey and then all of your tools can have a negative rake..

Bob


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