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Z offset on MCRN holder

Matt81

Plastic
Joined
Jun 22, 2019
Location
USA
Just got some new MCRNL holders at work so we can use the 100 degree edge on the pile of CNMG 543 inserts we have. I have an ongoing job I added this holder to do an OD rough and remove the nasty scale on forged stock. To be safe I set the Z offset from the protruding shoulder of the tool (see attached picture). My problem is Mastercam calculates the toolpath from the the tip of the tool closest to the part, so my first test setting the tool up was to rough a shoulder, but due to the difference in tool tip interpretation, the tool did not even touch the part. I've got it dialed in pretty well now, but honestly it was guesswork getting the tool offset set, the difference between the tip and the protruding shoulder is somewhere around .200". It's a rougher, before another rougher of a different grade, so it leaves a fair amount of stock.

My thought is that when setting my offsets, I can turn a clean face and OD on the stock as usual, then bring the tool in and scratch the OD, back off in Z, bring X in a thou or less, then jog Z in very slow and set Z0. when the tool makes first contact.

If anyone has any experience on how best to do this I'd appreciate the feedback, thank you.

Side note, getting these holders was great, the OD forge scale is roughed off with a Sandvik 4335 grade on the 100 degree edge, it flat rips through it. I follow it up with a MCLNL holder with a Sandvik 4305 or 4315 grade to finish roughing through the clean steel.
 

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The option here are endless due to how it is programmed and where the TNR is being done if you are using comp.
There is a Z touch off point out there on the back (or side) rad.
It's offset to the real tip side or center is fixed for a given insert radius and make.
You can find this number and Z shift too make it go away when setting. It will be constant if you do not change rad size.

This can sometimes be a problem in "Cs" if you change makers of inserts. The corner you are cutting with may not have the same radius as the normal working end of the tool.
A four tip may have a two, a two tip may have a zero.
Bob
 
Sir, thank you very much, I'll take a look. I need to dig into the tool setup tab in Mastercam a bit more as well.
 
Sir, thank you very much, I'll take a look. I need to dig into the tool setup tab in Mastercam a bit more as well.

Sounds like you have touched the tool off in machine at a different spot than how it is defined in Mastercam. If you look at the compensation for your tool/holder there are different options. One of them is for a tool like you are using where it defines bascially an intersection between the leading edge and trailing edge of insert. You will need to look into this tab (and the basic holder definition and angles) and make sure mastercam is matching how you are using the tool and setting it.
 
Mike, I took a look today and saw the tip comp settings in the tool definition. There's are a few options in there, found the one I needed, good to go!
 








 
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