CNC lathe Dealing with long chips

[PhilipTrueman]

I had a job turning some parts made from 6082 T6 aluminium. The part was 90mm in diameter.
The problem was after about 3 passes 30mm long, the turnings would get caught in the chuck jaws and i would have to stop the program and remove the swarf then start where the program stopped.
I thought it would be a good idea to use a face grooving cycle in intercon.
I programmed the face grooving cycle to take a 1mm cut in X and peck cutting every 2mm in Z. It worked well breaking the chips every time it pecked.
The swarf was now manageable and no turnings ever got wrapped around the chuck again.
I also use the part off cycle for deep grooves as you can peck cut to produce perfect length chips.
I couldn't get the chips to break without any other method. It is not a big lathe and has limited capacity.

[cnckeith]

thanks, i moved this post to the machining strategies forum.

[tblough]

Increase the feedrate or the depth of cut to make chips break.

[PhilipTrueman]

Increase the feedrate or the depth of cut to make chips break.

I tried increasing the depth of cut to 2mm off the diameter but it just tears the chips but still doesn't break the chips.
I tried increasing the feedrate but it is still the same.
I just set the feedrate to what it reccomends on the carbide insert box. I am using ground inserts for aluminium.
On steel it will break chips.
I need a larger lathe.

[suntravel]

Sometimes pecking is the best solution for chip control, on large lathes also.

Uwe

[RC-Lights]

hi, i am really new to intercon and i am wondering how can i use pecking for outer contour ?

Thanks
Michael

[suntravel]

hi, i am really new to intercon and i am wondering how can i use pecking for outer contour ?

Thanks
Michael

No function other than cut off cycle for this in Intercon.

For OD turning, hand code, or write a function with a sub program.

The easiest way is to use AW2007 or AW2011 instead of 6082

Uwe

[RC-Lights]

hi Uwe,

thank you. for Aluminium i dont have an issue, 7075 is producing nice short chips with f0,2 and 100vc.

i am more talking about titanium, it is very hard here to get short chips.

[suntravel]

jep 7075 is easy to cut, but if it is possible from spindle speed, I use 200m/min or faster.

No problem to write a chip breaking function with parameters for roughing, but for finish cut it looks better in one go with one long swarf.

The trick here ist to make it flow away from the part so it will not scratch the surface.

Uwe

[RC-Lights]

hi Uwe,

yes, 200m would be better, but i have often Diameters of 20mm or smaller, so the spindle would be always in Max Speed. So i try to find good parameters with lower Vc.

pecking macro for outer roughing is a good idea, but at first i have to get confident with Intercon itself.

the last cut is not the problem, the ap is small, so no thick swarf, not that dangerous. but i am looking for a solution for roughing and good process parameters for the boring bars.

Michael