Parts welding themselves to the skeleton when cut complete - Pirate4x4.Com : 4x4 and Off-Road Forum

jatepper · 03-02-2012, 08:31 PM

So I have been cutting some 3/8" steel lately. When I'm done with the cut, I find a lot of the parts are welding themselves to the skeleton instead of a complete separation. What gives? It does this on about half the parts.

carslut · 03-02-2012, 08:58 PM

what are you settings?

cut speed

cut height

pierce delay

amps

nozzle size

shielded or not?

THC?

ill have to check my settings but when i do cut 3/8 they come out clean and 90% ready to use. i could get them closer to being totally ready to use with a bit more fine tuning, i just don't do much 3/8 thick parts.

jatepper · 03-02-2012, 09:30 PM

Quote:

Originally Posted by carslut

what are you settings?

cut speed

cut height

pierce delay

amps

nozzle size

shielded or not?

THC?

ill have to check my settings but when i do cut 3/8 they come out clean and 90% ready to use. i could get them closer to being totally ready to use with a bit more fine tuning, i just don't do much 3/8 thick parts.

PM65
Poerce delay :.7
65a tip shielded
65a cut
45 ipm
Pierce:.15
Cut: .06
Using avhc

All book specs

carslut · 03-02-2012, 09:37 PM

do you have a photo?

jatepper · 03-02-2012, 10:22 PM

Quote:

Originally Posted by carslut

do you have a photo?

Tomorow. Yhanks

Richie_Rich · 03-04-2012, 07:02 AM

I assume you are talking about portions in the middle of a cut.
A picture would be nice, but the only times this happens to me is when the electrode or nozzle is spent. At that point, it doesn't even cut all the way through in some parts.
I can spot when it gets to that point by all the sparks being thrown out above the plate.

We have a very large industrial air compressor, but if yours is marginal, I'd be looking into that.
I suppose slowing the feed rate down could help to compensate.

jatepper · 03-04-2012, 07:40 AM

Quote:

Originally Posted by Richie_Rich

I assume you are talking about portions in the middle of a cut.
A picture would be nice, but the only times this happens to me is when the electrode or nozzle is spent. At that point, it doesn't even cut all the way through in some parts.
I can spot when it gets to that point by all the sparks being thrown out above the plate.

We have a very large industrial air compressor, but if yours is marginal, I'd be looking into that.
I suppose slowing the feed rate down could help to compensate.

I will get some pics later today. It is not in the middle of the cut at all. Basically where the lead in/out is. If I stick a screw driver in one of the holes and pull the part out the minute the outer perimeter is done cutting it will come right out. If I don't pull it out it will stick pretty good sometimes.

Richie_Rich · 03-04-2012, 08:24 AM

I was having that issue too.
I have now started to cut my parts with 0.1" over cut.(I can't remember the real term, but it's on the screen with the lead in settings)
Jim Colt posted something on this recently and he suggests using a lead out and also mentions about the "plasma off delay"
http://www.pirate4x4.com/forum/showt...217&highlight=

jatepper · 03-08-2012, 03:32 PM

OK......got my pictures finally. As you can see, I have a pretty nice lead in. The part welds itself at the end of the cut only. I have partially lifted this piece up and you can see it is stuck to the skeleton. I do not have a lead out and IIRC, the overburn was about .10.

There is a little nub where the piece did not completely sever where I had to rip it from the skeleton. This is AR500 steel...I do not have this issue with mild steel.

What do you all suggest?

Kmanator · 03-08-2012, 05:08 PM

I think your too fast on the speed.I cut 3/8 at 25 to 30 ipm with 60 amp tip and a TD cutmaster 151.
Opp's.[edit]..I just read it's ar500...but i still think it's too fast

jatepper · 03-08-2012, 05:38 PM

Quote:

Originally Posted by Kmanator

I think your too fast on the speed.I cut 3/8 at 25 to 30 ipm with 60 amp tip and a TD cutmaster 151.
Opp's.[edit]..I just read it's ar500...but i still think it's too fast

Hmmmm, I don't think so, but I'm not certain. I have a ton of low-speed dross (knocks off real easily). Maybe so, but I don't think that is the problem. Jim Colt told me that basically the cut specs for the AR500 should be the same as mild steel.

Any other thoughts??

Richie_Rich · 03-08-2012, 05:52 PM

What you are describing happens to me often.

Since I started doing the over cut or whatever its called, I don't have that problem very often. I normally use .1" of extra cut. I don't use a lead out.

BESRK · 03-08-2012, 05:57 PM

Have you tried a straight "lead-in"? I find the straight lead-ins give me the smallest divot and best "complete cuts". Ramping in with a "curved lead-in" would sometimes leave a little uncut area at the end of the cut. If you try to do too much overburn, you can find yourself with the torch diving in the "already cut" cut path. You could also do a "lead-out" to ensure a complete cut.. but I've never bothered.

On my 1250, there is very little degradation in cut quality from start to "shnozzle" of the nozzle. However, when my consumables have a bunch of pierces on them, they do "splash back" more than a fresh set.

I cut 3/8" at 41ipm with 60amps on my 1250 so I would imagine 45ipm would be pretty good at 65amps.

I'd try a straight lead-in on one and see what happens..

r08ert209cali · 03-08-2012, 06:46 PM

All I will say is AR500 cuts way different then mild steel. Do some line tests if you can afford it.

tfu · 03-08-2012, 06:49 PM

For a small fee ill gladly send you some Gcode that will fix that

ill even nest a full sheet for ya

jatepper · 03-08-2012, 07:29 PM

Quote:

Originally Posted by tfu

For a small fee ill gladly send you some Gcode that will fix that

ill even nest a full sheet for ya

Thanks Robert...lol. It is actually nested pretty efficiently. For whatever reason, the sheets of AR500 I get are extra big. More loke 51"x100". So, there is some unused area that eventually gets turned in to 3" gongs. My machine only travels 49", even though it is a 48" Y axis.

Yeah, time to do some line speed tests I guess.

tfu · 03-08-2012, 07:37 PM

Quote:

Originally Posted by jatepper

Thanks Robert...lol. It is actually nested pretty efficiently. For whatever reason, the sheets of AR500 I get are extra big. More loke 51"x100". So, there is some unused area that eventually gets turned in to 3" gongs. My machine only travels 49", even though it is a 48" Y axis.

Yeah, time to do some line speed tests I guess.

its a little more complex than just line speeds...you need to find a way to slow down the holes

HardcorewannabeXJ · 03-09-2012, 07:49 AM

I would first check your tip to work distance while it's operating, with a shade 6 goggle watch the arc and make sure it's running between 1/16" and 1/8". If you are having problems with severing the cut completely, going slower is generally going to allow the part to sever better due to the more time the plasma has to consume the material beneath it. Once you are getting completely severed parts, you can start bumping your speed to improve production and adjust the cut quality.

jatepper · 03-09-2012, 04:45 PM

Quote:

Originally Posted by BESRK

I'd try a straight lead-in on one and see what happens..

That fixed it! Good call Eddie!!

03-02-2012, 08:31 PM	#1 (permalink)
jatepper Registered User Join Date: Mar 2011 Member # 185144 Posts: 576	Parts welding themselves to the skeleton when cut complete So I have been cutting some 3/8" steel lately. When I'm done with the cut, I find a lot of the parts are welding themselves to the skeleton instead of a complete separation. What gives? It does this on about half the parts. __________________ TM2 4x8 w/Integrated H20 table, AVTHC, Hypertherm Powermax 65 Semper Fi! 1999-2004

03-02-2012, 08:58 PM	#2 (permalink)
carslut plasma dust huffer Join Date: Jan 2004 Member # 25823 Location: USA Posts: 1,854	what are you settings? cut speed cut height pierce delay amps nozzle size shielded or not? THC? ill have to check my settings but when i do cut 3/8 they come out clean and 90% ready to use. i could get them closer to being totally ready to use with a bit more fine tuning, i just don't do much 3/8 thick parts. __________________ *Duramax and LS based motor tuning* Offering in House Custom CNC Plasma cutting services, we can take your idea from design to your doorstep. have a sketch you want to become parts for your project? pm me, i can help. parts are shipping out daily "it makes the mach5 look like a vagina" - ARCHER

03-02-2012, 09:37 PM	#4 (permalink)
carslut plasma dust huffer Join Date: Jan 2004 Member # 25823 Location: USA Posts: 1,854	do you have a photo? __________________ *Duramax and LS based motor tuning* Offering in House Custom CNC Plasma cutting services, we can take your idea from design to your doorstep. have a sketch you want to become parts for your project? pm me, i can help. parts are shipping out daily "it makes the mach5 look like a vagina" - ARCHER

03-08-2012, 03:32 PM	#9 (permalink)
jatepper Registered User Join Date: Mar 2011 Member # 185144 Posts: 576	OK......got my pictures finally. As you can see, I have a pretty nice lead in. The part welds itself at the end of the cut only. I have partially lifted this piece up and you can see it is stuck to the skeleton. I do not have a lead out and IIRC, the overburn was about .10. There is a little nub where the piece did not completely sever where I had to rip it from the skeleton. This is AR500 steel...I do not have this issue with mild steel. What do you all suggest? __________________ TM2 4x8 w/Integrated H20 table, AVTHC, Hypertherm Powermax 65 Semper Fi! 1999-2004

03-08-2012, 05:08 PM	#10 (permalink)
Kmanator Registered User Join Date: Feb 2012 Member # 211136 Location: Top of a mountain in the woods Posts: 30	I think your too fast on the speed.I cut 3/8 at 25 to 30 ipm with 60 amp tip and a TD cutmaster 151. Opp's.[edit]..I just read it's ar500...but i still think it's too fast Last edited by Kmanator; 03-08-2012 at 05:10 PM.

03-04-2012, 07:02 AM	#6 (permalink)
Richie_Rich Registered User Join Date: Apr 2011 Member # 188229 Location: St. Charles, MO Posts: 245	I assume you are talking about portions in the middle of a cut. A picture would be nice, but the only times this happens to me is when the electrode or nozzle is spent. At that point, it doesn't even cut all the way through in some parts. I can spot when it gets to that point by all the sparks being thrown out above the plate. We have a very large industrial air compressor, but if yours is marginal, I'd be looking into that. I suppose slowing the feed rate down could help to compensate.

03-04-2012, 08:24 AM	#8 (permalink)
Richie_Rich Registered User Join Date: Apr 2011 Member # 188229 Location: St. Charles, MO Posts: 245	I was having that issue too. I have now started to cut my parts with 0.1" over cut.(I can't remember the real term, but it's on the screen with the lead in settings) Jim Colt posted something on this recently and he suggests using a lead out and also mentions about the "plasma off delay" http://www.pirate4x4.com/forum/showt...217&highlight=

03-08-2012, 05:52 PM	#12 (permalink)
Richie_Rich Registered User Join Date: Apr 2011 Member # 188229 Location: St. Charles, MO Posts: 245	What you are describing happens to me often. Since I started doing the over cut or whatever its called, I don't have that problem very often. I normally use .1" of extra cut. I don't use a lead out.

03-08-2012, 05:57 PM	#13 (permalink)
BESRK Rock God Join Date: Jan 2004 Member # 26393 Location: Newport News, VA Posts: 1,158	Have you tried a straight "lead-in"? I find the straight lead-ins give me the smallest divot and best "complete cuts". Ramping in with a "curved lead-in" would sometimes leave a little uncut area at the end of the cut. If you try to do too much overburn, you can find yourself with the torch diving in the "already cut" cut path. You could also do a "lead-out" to ensure a complete cut.. but I've never bothered. On my 1250, there is very little degradation in cut quality from start to "shnozzle" of the nozzle. However, when my consumables have a bunch of pierces on them, they do "splash back" more than a fresh set. I cut 3/8" at 41ipm with 60amps on my 1250 so I would imagine 45ipm would be pretty good at 65amps. I'd try a straight lead-in on one and see what happens.. __________________ Little CJ5 on 35s.

03-08-2012, 06:46 PM	#14 (permalink)
r08ert209cali Locked & Loaded 4X4 Join Date: Feb 2010 Member # 153769 Location: Modesto,Ca Posts: 431	All I will say is AR500 cuts way different then mild steel. Do some line tests if you can afford it. __________________ Bad Ass LED light bars http://www.kmdgarage.com/quantum-led-lighting-1/

03-08-2012, 06:49 PM	#15 (permalink)
tfu Registered User Join Date: Dec 2011 Member # 205869 Posts: 37	For a small fee ill gladly send you some Gcode that will fix that ill even nest a full sheet for ya __________________ [URL="https://www.targetsfromus.com"]Very affordable shooting target stands & AR500 targets [ www.targetsfromus.com ][/URL]

03-09-2012, 07:49 AM	#18 (permalink)
HardcorewannabeXJ Registered User Join Date: Jan 2007 Member # 84593 Location: Reno, NV Posts: 3,004	I would first check your tip to work distance while it's operating, with a shade 6 goggle watch the arc and make sure it's running between 1/16" and 1/8". If you are having problems with severing the cut completely, going slower is generally going to allow the part to sever better due to the more time the plasma has to consume the material beneath it. Once you are getting completely severed parts, you can start bumping your speed to improve production and adjust the cut quality.

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