Uneven stepover in pocketing

[?Mark]

Hi all.

I'm doing a pocketing (constant overlap standard)and looks like stepover is uneven.

I'm doing a regular pocketing of a rectangle(going outside to inside) and stepover is .125" on 3 sides (right, botttom and left) but is .150" on the top

At first I thought it was my servos (machine load was different) but checked a toolpath and there it was

Went back to MCX and saved toolpath as geometry and it confirms this.

 

What gives?

 

Regards, Mark

[Steel Surgeon]

Tried it and it does what you say. I am not sure why.

[?Mark]

Just confirmed it by creating a 5x5 square(with no islands this time) and milling it with a .500 em and .125 stepover.

The same thing happened.

 

Hope it's not another MP issue here

 

Mark

[Yogesh K. Raman]

correct me if i'm wrong but i think the constant overlap spiral is supposed to be this way.

 

i tried comparing the toolpath in VX and V9 and it does the same thing.

for a more tighter stepover tolerance u can go to the Advance button under the pocketing parameters tab of the toolpath and make it tigher, by default its 5% of tool diameter.....

[Yogesh K. Raman]

assuming ur using 0.5 em, then a 0.125 stepover should vary within +/- 0.025 hence the 0.150 stepover.

[?Mark]

quote:

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pocketing parameters tab of the toolpath and make it tigher, by default its 5% of tool diameter

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It was there all those years and I didn't see it

Thanks for the reply Yogesh, tightening this tolerance changed toolpath accordingly as you said it would.

 

 

Mark

[Roger Peterson]

This is one of the things I change ASAP with every new version. It does not just control the stepover of constant overlap spiral, it also controls how accurately remachining is calculated. I typically change mine to 1% as the default. Occasionally I will have to drop this down to .5% if I am working with larger tools.

 

 

HTH

[?Mark]

Roger

quote:

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I typically change mine to 1% as the default.

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That's exactly what I did for all machines.

In this case I noticed a machine load get from 40% to 50% and thought my tool was getting bad. As it turns out it was taking a bigger cut...

 

 

Mark