45 amp hypertherm cutting 5/16" plate

[Waylon80]

Hey does anyone have any good specs they care to share on cutting 5/16" plate. I've tried just about everything and nothing's really turning out worth a count.

[tnbndr]

I would use the cut settings for 3/8" mild steel.

[Waylon80]

I would use the cut settings for 3/8" mild steel.

3-8 cut chart.JPG

Did your parts turn out good? Because I had it set for 35 feed rate 120 volts and I was able to cut 13 out of 42 2.5"x4" brackets then on the 14th bracket it wouldn't cut all the way through instead it was practically engraving the bracket in the plate itself so I thought maybe consumables were worn so put new ones in and Started Mach again to start cutting at bracket #15 (since #14 was ruined) and it cut #15 fine then moved to start cutting #16 and then messed up again and would only engrave the plate instead of cutting all the way through just like #14 did. But I did notice on bracket #16 that it did piece all the way through but just as soon as it started the lead in it quit cutting through and the cut itself would gradually rise so by the time it got to the end of the lead in to start cutting the part I was barely grazing the top of the plate. I looked at where Mach to see where my z axis was sitting at during the cut height when I stopped it mid way through the cut and it was at 0.14 which surprised me because in G code it was set to cut at 0.06 cut height. So something caused the dthc to raise the torch while starting the lead in. Any suggestion?

[jimcolt]

Use the 3/8" specs......but go a bit faster on the cut speed.....I would suggest about 40 ipm.

-If your height is not staying within .005" of the recommended .06".....then you will have to determine what is wrong with your height control system.

-Make sure you are using the machine torch shield......not the hand torch shield.

-Monitor your inlet air pressure by installing a gauge right at the inlet....it must always be between 90 and 120 psi while air is flowing at the torch. If it drops below 90 expect cut issues. Do not rely on any gauge that is further upstream....such as the one at your compressor....they will not show the pressure at the inlet.

-Be sure that when you set the cut pressure (using the onboard regulator and the front panel LED's) that you are doing it with air flowing at the torch (do this by turning the amperage knob fully counter clockwise)....and monitor the gauge on the rear panel while doing this to ensure pressure is above 90 psi.

Here is a picture of 3/8" cut with a Powermax45.....your 5/16" will look the same if all of the above are correct. Jim Colt Hypertherm

Powermax45 edge angle 003.jpg (28.45 KiB) Viewed 2724 times

Powermax45 edge angle 003.jpg (28.45 KiB) Viewed 2724 times

[acourtjester]

It sounds like your DTHC is having a problem, have you tried turning it off and cut without it controlling the Z motion?
Have you watched the arc voltage while cutting it should remain constant shortly after the pierce. G-code cut height is only for the starting of the cut and the DTHC controls the torch height after.
As long as the material is not warped you should cut good without the DTHC with the G-code starting the cut at 0.060" after the pierce.

[Waylon80]

Use the 3/8" specs......but go a bit faster on the cut speed.....I would suggest about 40 ipm.

-If your height is not staying within .005" of the recommended .06".....then you will have to determine what is wrong with your height control system.

-Make sure you are using the machine torch shield......not the hand torch shield.

-Monitor your inlet air pressure by installing a gauge right at the inlet....it must always be between 90 and 120 psi while air is flowing at the torch. If it drops below 90 expect cut issues. Do not rely on any gauge that is further upstream....such as the one at your compressor....they will not show the pressure at the inlet.

-Be sure that when you set the cut pressure (using the onboard regulator and the front panel LED's) that you are doing it with air flowing at the torch (do this by turning the amperage knob fully counter clockwise)....and monitor the gauge on the rear panel while doing this to ensure pressure is above 90 psi.

Here is a picture of 3/8" cut with a Powermax45.....your 5/16" will look the same if all of the above are correct. Jim Colt Hypertherm

Powermax45 edge angle 003.jpg

Thanks Jim I'll give it a try. What do you recommend on:
*Plunge rate (mine is set to 150)
*leadin type (I tried normal but someone recommend doing a ramp to keep it from blowing back up at the tip)

[redheadfred]

It could be your pwm module or whatever module your running on yours for the torch height . I was having a similar problem a couple weeks ago and that's what my problem was . Mine ran 16 gauge fine but acted crazy on 12 gauge .

[jimcolt]

Use whatever lead in works best for your machine. Plasma likes a straight lead in.....however if your machine has any backlash or has sluggish acceleration....that type of lead in will create a divot at the transition between lead in and the actual part shape. Looser, lower acceleration machine will do better with an angled or radial lead in.

Plunge rate....not sure exactly what that is (I'm guessing it is the down speed of the z axis?)......as long as the z axis (height control) is not oscillating up and down at any time during the cut...then this is probably ok. The powermax45 is designed to pierce up to 1/2".....no special technique is needed, just follow the specs for pierce height and pierce delay time in the operators manual. Jim Colt Hypertherm

[tnbndr]

Did your parts turn out good?

Yes, I get good cuts.
I am guessing here but are you just setting the volts to book specs without doing a test cut with your THC off? Test cut a straight line about 12" long with THC off and watch what the voltage levels off at in Mach 3. That should be what you set for your preset voltage for that material and thickness.

[Waylon80]

Use whatever lead in works best for your machine. Plasma likes a straight lead in.....however if your machine has any backlash or has sluggish acceleration....that type of lead in will create a divot at the transition between lead in and the actual part shape. Looser, lower acceleration machine will do better with an angled or radial lead in.

Plunge rate....not sure exactly what that is (I'm guessing it is the down speed of the z axis?)......as long as the z axis (height control) is not oscillating up and down at any time during the cut...then this is probably ok. The powermax45 is designed to pierce up to 1/2".....no special technique is needed, just follow the specs for pierce height and pierce delay time in the operators manual. Jim Colt Hypertherm

Thanks Jim I gave it a try last night with the specs you mentioned for 3/8" though I forgot to bump up federate to 40 like you said. I cut it at exactly like stated in the manual and here's some pictures of the part. Good news is it did actually cut it out instead of engraving it so that's good. Also I noticed it had a bad bevel bottom beveled out on one side and on other side the bottoms beveled inwards though I think that could be because my torch might be alittle out of level sitting in the torch mount.

[Waylon80]

Here's some more pictures any idea on why there's so much dross. I had to beat on the part to try to get it off the table it was like it had kinda welded itself to the plate on the bottom with all the dross. Though after I finally got it out I was able to remove the dross with a good amount of force with just a hand scraper.

[Waylon80]

Did your parts turn out good?

Yes, I get good cuts.
I am guessing here but are you just setting the volts to book specs without doing a test cut with your THC off? Test cut a straight line about 12" long with THC off and watch what the voltage levels off at in Mach 3. That should be what you set for your preset voltage for that material and thickness.

No I haven't done that yet. I know what your talking about but unsure as to the proper way to turn the THC off because everytime I've tried I'm not sure if it the dthc itself or what but something always turn it back on. You care to explain the proper process for turning it off because I've tired a bunch of things with no success. I'm running candcnc's DTHCIV BLADERUNNER using MACH3 and SHEETCAM.

[SeanP]

This is one I just got out of the bin, cut at 750mm/min (29.5''/min) Powermax 45
I would say your consumables aren't up to scratch or cutting at wrong height, something so small won't need thc on though.

[SeanP]

No I haven't done that yet. I know what your talking about but unsure as to the proper way to turn the THC off because everytime I've tried I'm not sure if it the dthc itself or what but something always turn it back on. You care to explain the proper process for turning it off because I've tired a bunch of things with no success. I'm running candcnc's DTHCIV BLADERUNNER using MACH3 and SHEETCAM.

You need to create cut rules in Sheetcam to turn off dthc.

I think you can also us the middle green button as on the screen below to manually turn off thc, mine is the parallel port version but I think it's the same setup.
On thicker stuff (6mm+)where you have more time I quite often turn off thc manually, watch the torch volts until it comes off the thc delay/stabilises, then quickly dial in the torch volts reading into the preset volts and switch thc button back on, works very well.

[Waylon80]

No I haven't done that yet. I know what your talking about but unsure as to the proper way to turn the THC off because everytime I've tried I'm not sure if it the dthc itself or what but something always turn it back on. You care to explain the proper process for turning it off because I've tired a bunch of things with no success. I'm running candcnc's DTHCIV BLADERUNNER using MACH3 and SHEETCAM.

You need to create cut rules in Sheetcam to turn off dthc.

I think you can also us the middle green button as on the screen below to manually turn off thc, mine is the parallel port version but I think it's the same setup.
On thicker stuff (6mm+)where you have more time I quite often turn off thc manually, watch the torch volts until it comes off the thc delay/stabilises, then quickly dial in the torch volts reading into the preset volts and switch thc button back on, works very well.

mach.jpg

Yeah on my mach3 screen I don't have the middle button at all that your talking about. On my mach3 on the program run screen I have 2 buttons to turn mach3's THC on/off and Torch on/off. But if I hit the tab key for the fly out window I have the normal button to turn the DTHC on/off. I've tired turning both the THC and DTHC off but that only last for one cut then turns itself back on because it's programmed in g-code for each cut to turn it on at the beginning of the cut then turn it off at the end then turn it back on at the beginning of the next cut all automatically. So from the sounds of it I'll have to find away to do it through sheetcam so It'll be in the gcode for it to stay off. But that I have no clue on how to do?

[Waylon80]

This is one I just got out of the bin, cut at 750mm/min (29.5''/min) Powermax 45
I would say your consumables aren't up to scratch or cutting at wrong height, something so small won't need thc on though.

8mm.jpg

The specs I cut it at was:
32 feed rate
122 preset volts
0.15 pierce height
0.06 cut height

The consumables should be fine because like I said in an earlier post. It wasn't cutting all the way through then I put brand new electrobe and nozzle on then tried cutting again and was able to cut one of the bracket's (which looked the same as the one I posted a picture of) then tried cutting another one and it would not cut it all the way through would only etch it. So I then tried the 3/8" thick setup like Jim mentioned and I was finally able to get it cut out but it don't look to pretty. Sad part is I've got to cut 40-60 of these a month. This is the first time we've cut anything this thick normal cut 11 gauge so we're trying to get all the kinks worked out for it to cut right or atleast decent.

[SeanP]

The thc button should/will overide the thc in gcode.
Where did you get preset torch volts of 122?
I found book settings nearly 10v out on my setup, you might be the same, it's just calibration I think, it's not a problem you just take note, also as the electrode burns down torch volts increase by up to 4 or 5v.

[SeanP]

Sorry missed that bit, it's the THC button next to the torch fire button that will disable thc regardless of code.

[Waylon80]

The thc button should/will overide the thc in gcode.
Where did you get preset torch volts of 122?
I found book settings nearly 10v out on my setup, you might be the same, it's just calibration I think, it's not a problem you just take note, also as the electrode burns down torch volts increase by up to 4 or 5v.

I used the specs from the hypertherm pm45 manual for cutting 3/8" like Jim colt had mentioned. That's where I got 122 for the preset volts. As far as mach3 yeah that's exactly how mine looks but anyways I'll try it again to see if it'll work right for me but I believe if keep turning it back on right after the next pierce. So exactly when do I need to click it to turn it off also what about the dthc button on the fly out window? Do I need to do anything with it?

[SeanP]

To confirm that 122v preset is right for your setup you need to cut a small test part with straight edges maybe 4'' long x 1/2" wide on that thickness, with thc off and see what the torch volts actual reading is while its cutting along the long edge, if it's different then use that as the new volts preset, then when thc is turned back on the cutting height will be matched to the test cut.
It's not easy getting to grips with it all, it taken me a couple of years and I'm still learning.
It's not easy trying to explain it as well, hope it makes sense to you.

[Waylon80]

To confirm that 122v preset is right for your setup you need to cut a small test part with straight edges maybe 4'' long x 1/2" wide on that thickness, with thc off and see what the torch volts actual reading is while its cutting along the long edge, if it's different then use that as the new volts preset, then when thc is turned back on the cutting height will be matched to the test cut.
It's not easy getting to grips with it all, it taken me a couple of years and I'm still learning.
It's not easy trying to explain it as well, hope it makes sense to you.

On yeah it makes plenty of sense to me. I'll give it another try and see if I can get the THC to stay off and give it a try to see what it reads.

[tnbndr]

I do mine in SheetCam. Now this was set up for the most part for me by Dan at LDR. I created a tool called material, NO THC and on the bottom line you can see THC on is 1 and off is 0. See if these pics help. Not sure if the snippet codes are located elsewhere in the post program but I would assume they are.

The code snippet for THC on is S20

THC Tools.JPG (57.08 KiB) Viewed 2627 times

THC Tools.JPG (57.08 KiB) Viewed 2627 times

THC Off.JPG (45.77 KiB) Viewed 2627 times

THC Off.JPG (45.77 KiB) Viewed 2627 times

[Waylon80]

I do mine in SheetCam. Now this was set up for the most part for me by Dan at LDR. I created a tool called material, NO THC and on the bottom line you can see THC on is 1 and off is 0. See if these pics help. Not sure if the snippet codes are located elsewhere in the post program but I would assume they are.

The code snippet for THC on is S20

THC Tools.JPG

THC Off.JPG

Hey thanks if I do it that way in sheetcam is there anything else I need to do in mach3 pertaining to the THC & DTHC buttons?

[tnbndr]

Hey thanks if I do it that way in sheetcam is there anything else I need to do in mach3 pertaining to the THC & DTHC buttons?

I don't do anything else in Mach 3.
Hope that helps you, as I say it was all set up for me so I'm not sure what is all in the post processor.
Good Luck, I'll be MIA for a while on a long needed vacation.

[jimcolt]

The dross is from cutting too slow. The varying angularity indicates a damaged nozzle and/ or shield orifice....probably caused by the previous (not cutting all the way through) issue......this causes blowback on the torch and damages consumables.

Physical cut height is more important than setting the arc voltage to book specs. The "book" voltage is correct when everything else (cut speed, cut air pressure, new consumables) is correct. Adjust the voltage once you have all other specs where you want them.....until the physical height during cutting is correct (.06" in this case).

Some height controls (Plasmacam and others) use voltage sampling to auto set the arc voltage.....so on those systems you do not need to set arc voltage)

Jim Colt Hypertherm