Parting off

[Thoob]

Hey fellas, just wondering how you adjust the speed and feed when parting off? I mean slow everything down at the end so the part doesn't go flying. Of course I mean without manually editing the program.

[jhjr]

The toolpath editor will change feeds but not speeds. Maybe use grooving instead of cutoff? Let whatever amount you want for your depth in roughing then use a different speed & depth for finishing. Even better maybe 2 point toolpaths? Hth

 

[ 09-30-2010, 10:39 PM: Message edited by: jhjr @ Mclanahan Corp ]

[Jeremy Grigsby]

look on the lower right of the parameters box. It is where lead in and lead out are located. There is a special parameter box for cutoff paths that lets you specify rpm changes at certain radiuses. Can't tell you exactly because i am not at work yet.

[chris m]

Max spindle speed for me, man. I post the correct SFM but limit the spindle RPM to 1000 or so to keep the parts from flying around; G50 is your friend

[Goldorak]

i use the lead out of partoff

 

set the X point a .1 and set lead-out at -90° x .100lg and don't use the lead-in

 

then i set a new feedrate in the box

be awarw to not check the "use rapid feed rate for vectors"

[jeff]

quote:

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Hey fellas, just wondering how you adjust the speed and feed when parting off? I mean slow everything down at the end so the part doesn't go flying. Of course I mean without manually editing the program.

---

only cut down to a certain diameter.

for example: if the part has a 4" ID, take the partoff tool down to 4.002 and then smack it with a rubber mallet, it will pop right off.

 

tip: if you do it this way, make sure to smack the part on the face, not on the OD, it will come off much easier.

HTH

[horsepowered]

I use misc reals and integers to create a cutoff from the last operation. That way the program will slow the feed at the end. All I need to do is change the bar diameter and part length and stock to leave. Feed rate and speed usually remain the same but can be changed. I do the same for sub spindle transfer. Much easier for me.

[Josh T™]

quote:

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just wondering how you adjust the speed and feed when parting off? I mean slow everything down at the end so the part doesn't go flying.

---

I just G96 the speed and use sub-spindle support to pick off on the fly. You guys don't do this too???

[Thoob]

Thanks for the replies guys. I have a lot of suggestions now.

[Thoob]

quote:

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Max spindle speed for me, man. I post the correct SFM but limit the spindle RPM to 1000 or so to keep the parts from flying around; G50 is your friend

---

This way takes too long to part off. I've done this before.

 

quote:

---

look on the lower right of the parameters box. It is where lead in and lead out are located. There is a special parameter box for cutoff paths that lets you specify rpm changes at certain radiuses. Can't tell you exactly because i am not at work yet.

---

quote:

---

i use the lead out of partoff

 

set the X point a .1 and set lead-out at -90° x .100lg and don't use the lead-in

 

then i set a new feedrate in the box

be awarw to not check the "use rapid feed rate for vectors"

---

These 2 ways don't allow me to change RPM.

 

quote:

---

only cut down to a certain diameter.

for example: if the part has a 4" ID, take the partoff tool down to 4.002 and then smack it with a rubber mallet, it will pop right off.

 

tip: if you do it this way, make sure to smack the part on the face, not on the OD, it will come off much easier.

HTH

---

I do this now. I want to avoid it, lol.

 

quote:

---

I use misc reals and integers to create a cutoff from the last operation. That way the program will slow the feed at the end. All I need to do is change the bar diameter and part length and stock to leave. Feed rate and speed usually remain the same but can be changed. I do the same for sub spindle transfer. Much easier for me

---

This sounds interesting except I'm new to to the lathe add on. Can you elaborate a little more?

 

quote:

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I just G96 the speed and use sub-spindle support to pick off on the fly. You guys don't do this too??? [Wink]

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I am a little confused on this as well. I never use RPM when parting so I'm with you on G96 but what is sub-spindle support?

[Cannon]

I have the same problem with indexable drill, how do I slow down the rpm´s right before the drill goes thru the part? I want to know this because the center bit from the hole hits the lathe window and shatters it.

[crazy^millman]

Make is a point toolpath. Then go to the toolpath editor and put a spindle speed in to control the exact speed or feed you want when punching through.

[butlermere]

Point toolpaths seems to only give you feed change option wheras if you create some finish toolpath geometry, in sections, and chain it for finish tool path. Then click on geometry chain to pop up chain manager.Right click your chain and choose 'change at point'. Then you follow the prompts to select the section to change and this will give your options for speeds/feed. Don't forget your changes stays in effect onwards.

[butlermere]

P.S.

Your effectivly creating geometry to drive your part off tool down.

[Richard Thomas - Mastercam UK]

You will be able to slow the spindle speed as well as the feedrate at a radius of your choosing in X5

[Josh T™]

quote:

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I'm with you on G96 but what is sub-spindle support?

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We use our B Axis (Sub Spindle) to chuck the turned end of the part when we part off. We sync the spindles and part it off with no xxxx, burr, or part flying around... also called "Picking off on the fly". Those who don't have a sub spindle don't have this luxury. I was generally being a smarta$$ on my original reply... sorry for the confusion.

[Thoob]

ahhh. I don't have that luxury, lol