New table issues

[Dfrick23]

Ok guy been here for a little while but never posted before because my table was a home brew style get ya by kinda thing and I never have accomplished anything really worthy to share.. I'm 6 months into cnc and have now upgraded to a new table.. It's a precision plasma gantry with a diy magnetic breakaway running with mach3, sheetcam, proma thc geko540 and sheetcam on Windows 7 and a hypertherm 45xp genuine consumables . Cuts are decent, mostly geometrical (the holes still suck but im working on them) but I've got problems and I really hope that someone here can help answer.. I wish I knew someone local that could come help me set it up... long story short. I have dross out the yang running anywhere from just under book specks to up to what will still maintain the cut as far as the ipm go,neither speed seems to matter alot. voltage is a different story to keep the height right .06 cut (on 3/8 steel , standard shielded consumables) book spec is 137, I run at 100 or it's way off the sheet .5 in or more( figured that was the proma because it was the same way on the last table.. the proma does work like it should outside of that and will mostly maintain the height ( slow to do so in my opinion) however the voltage is off from spec.... another thing im running the latest licensed mach three, half the time when I hit start it will hang on line three says 3:n0040 g20 (units:inches).. the dro and movement stop but mocks timer still runs. If i reset the code and it will do the same thing over and over, ticks me off after a while because I have to restart mock3, reset the table, reload the file and then go.. once in a blue moon I can deal with, but this is like every 3rd start I make, and I make alot just trying to learn this stuff.. sorry for the unload but im at wits end.. many hours trying to figure this stuff out the hard way .. thanks guys, hope to soon be in a league with most of you and be able to give back.. I know this table and cutter will perform, I think the real problem here is ignorance so any help would be very much appreciated

[djreiswig]

Could your height issue be an incorrectly set voltage divider board? Just a thought.

[Dfrick23]

I'm not sure, I will research the issue in the plasma and check into it. It's whatever factory is as it was bought new. the proma is attached directly to the hypertherm through the connector in the back like the manual says

[Dfrick23]

Hypertherm book says 50:1 Is the factory preset voltage divider in the cutter. I used shielded cable and grounded the shielding to the table and it's grounded to an earth rod outside. Don't think emf is a problem as the voltage is fairly consistent but I could be wrong...

[acourtjester]

There are a few thing you should try, first is to just cut some straight lines like 6" long without the proma being on. Have a g-code to pierce at 0.160" 45 amps, cutting height 0.060" cutting speed at 37 IPM for the 3/8" mail steel. See what it looks like, it should have a very small amount of dross on the bottom compared to what you show. This will tell you if you setup will cut correctly. You said with the porma you are running at 100 volts and the torch is way off the metal this is not right. When you do this look at the proma voltage display and see what it shows. Either the voltage divider is not set at 50:1 or the proma is not working right. I have used promas and have found they need to be run using the raw voltage out of the Plasma unit. The proma has 2 input voltage signals wither raw or 50:1.
Where are you located?

[Dfrick23]

Thanks guys, it it wired just as the book shows on the dv terminals, I run it at 100 because that appears to be just off the sheet. The book setting of 137 is where it climbs really high.. I will check it with a feeler gauge on a dry run but it can't be too far from the .06. If the problem is the proma I don't mind swapping it for a better thc.. I will read up more on what others are using for their thc on here in Case I do need to swap it out.. I will also swap it to use raw voltage and see if that helps it out, i know its a budget thc but that's what I had to get at the time... it was "better than nothing" I think

[Capstone]

I have a PM45 and the same divider issue is at play here I believe. My readings on voltage were (and still are) wonky compared to what now are two completely different THC systems readings at the screen. (C&CNC and JD Squared)

I don't have an answer for you on that, but I want to solve the real problem here... helping you make good cuts... not messing with electronics that aren't needed on thicker cuts

I don't see any utility in messing with your THC on thicker stuff. THC is a known solution for thinner metal warping, but has little affect on anything thicker than 11g stuff. I stopped using mine and just run it from actual book settings from HT.

Like Jester says, run it on some scrap for a good straight distance and monitor the voltage. You might have to trick the PROMA/MACH into matching a voltage other than what the book says, just to maintain the .060 cut height.

[Dfrick23]

Will do, thanks guys, soon as I get home tonight I will run some cuts without the thc again but that's how I came up with the 100 volt setting, strange that all the thc read a little different.. I'm in New London NC.. certainly willing to pay for someone's time and experience for some set up checking and training.. pretty much what I know is what I've learned from this forum and google... things I know are good, air supply is plenty, clean and dry, cutter works great ( ive deslagged a many of sheets now) and the new gantry is smooth and has no lash in anything that I can see, it's tuned well i think and can move pretty darn quick without skipping or stalling.. i know its not a 20k unit but i like it, just gotta work the bugs out of it..i will post some new pics tonight, will set it up at .06 with no thc at 37ipm and see what it will do.. thanks again for you're time, and help

[acourtjester]

Question are you running a proma 150 or SD?

[Dfrick23]

It's the compact 150. I Just got in gonna go do those test cuts in a min.

[Dfrick23]

Ok here I have leveled the sheet with the nozzle, proma reads 100 the whole time it's cutting, stopped in a dry run and gap measures right at .06 so from left to right is 34ipm 35 36 and 37 was gonna do 38ipm but it won't maintain the cut, I know from very previous attempt with 38ipm and I hate to keep burning nozzles doing it. Thoughts and suggestions? Also is there a way to load a video to this fourm?

[Dfrick23]

https://youtu.be/d8RjpWDVypQ here's a video of the mock glitch I was referring too.. notice it's on cut three.. restart n reload the file..

[acourtjester]

That is some really bad looking cuts, the video show nothing as it is not cutting. I assume that this image is the bottom of the cuts you made.
What is the pressure of the air supply to the back of the plasma unit. You say burning nozzles are you having a problem with short nozzle life?? If you zip the video file you may be able to post it here, WinRAR is a free program you can download and then compress the video and post it.

[Dfrick23]

Yea that is the back of the cut, front side looks decent enough to me. That is a video of mock 3 locking up on line 3. Stops outputting anything buy the timer keeps running. I Have to close the software reopen and reload.. really annoying..been working on the holes and line cuts looks like 37.5ipm is best for dross. Still a lot there though imo from what I see you're guys cut quality.. pressure at hypertherm is 90 psi regulated.. was running higher but that's what the unit says to run so I backed it down.. the nozzle life I was talking about was from cutting to fast.. It seems to burns a small crater in the edge of the nozzle pretty quick when it sprays up from to not cutting through..

[Dfrick23]

Here's a cut video testing holes, corners, and dross.. best I've seen yet.. https://youtu.be/jDgjgxwee8s

[acourtjester]

I missed a fact which you gave, the voltage is a result of the cutting perimeters and is used to control the torch height when a THC is used. The test where the type of metal, cut height, cut speed, amps, nozzle and with a hypertherm plasma will result in a given voltage and the expected good cut. That is shown in the manual after their testing to show what to use with a THC to maintain the correct height.
Now you said the voltage display was 100 so there is a problem there with the voltage out from the divider or the proma. This is only a problem if the THC is controlling the cut height as it would cause the torch height to change. It seems from the video your main problem is the large amount of dross.
With the air pressure do you have a gauge at the back of the hypertherm itself. You may have a pressure drop while cutting which would show at that gauge, one back at the compressor may not. This could cause your starting problem also. these post talk about similar things
http://www.plasmaspider.com/viewtopic.p ... op#p138382
http://www.plasmaspider.com/viewtopic.p ... op#p126191

[Dfrick23]

I'm gonna try to rewire the thc to a raw voltage setup and see if that at least gets the readings closer to book values.. looks like some people do use proma without issue.. i have a seperate regulator / water,oil seperator and dryer at the table.. gague on it never drops much while it's running, the compressor kicks on after a minute of cutting,will build up and shut off while it's still cutting.. I'll attach a different air line to the cutter, maybe there is a volume issue with one of the couplers on that line or the separator itself . I've never pulled the filter out of the hypertherm itself, I'll take a look at it too.. thanks again for you're time and help. I had ran out of ideas and tried all I know.. thanks for the links too, im gonna look into some possibilities there too..

[Dfrick23]

Ok stupid question,do you suppose that I could have the two hot legs crossed on the 240 going to the cutter and that be causing problems? It's always been my understanding they didn't matter in a single phase circuit?

[djreiswig]

Shouldn't matter. Both are 120 hot legs.

[Dfrick23]

cool thanks, thats what I was thinking.. filter in the unit looks fine, slight brown tint but seems to flow well blowing through it.. i just dont understand why the dross? even with brand new oe consumables.. looking at the cut as it happens, the arc under the sheet is lagging behind like it has to catch up, ive seen jim talk about it being infront of the cut but this one has never done that that ive seen.. could that be a helpful clue??

[acourtjester]

I have not cut any 3/8" that I can remember but the thing is the hypertherm manual for the 45Xp states 37 IPM for 3/8". Jim has said dross is caused by low speed. What size wire are you using to supply the input to the plasma unit, the manual calls for 10 Ga 3 conductor with a 50 amp breaker. Jim has stated the 45 XP has more power out for cutting then the older PM 45 units. Maybe some other here that have the 45 XP and have cut 3/8" will jump in with comments, but you should get better results in cutting with that unit.

[tnbndr]

Are you certain you have proper air supply to cutter while it is running? Also make sure it is in the correct cut mode. I've inadvertently switched mine to gouge setting and it cuts terrible.

[Old Iron]

What I've read in Jim's post is the cut lines should be at a 15 degree angle behind the travel direction.

[Dfrick23]

Hey guys it is on a 10/3 wire about 30 foot long from the breaker box on a 50 amp breaker.. headed to do some cuts with a different air supply line.. maybe something is up with the seperator/dryer.. n it's running in cut mode, been there before, tried marking some plates onetime and forgot to switch it back before starting a new process.. that is kinda the way it acts though, that was one of the things I checked first. will update soon with info on the other air line

[Dfrick23]

Well no luck.. maybe I'm just stuck with slag on 3/8 plate.. tried all different speeds and a different air line.. new consumables and this is what I have.. also adjusted air pressure on the cutter but it just seemed to make it worse.. im open to ideas because thats pretty much all we ever cut.. I do some .25 in. As well but it's always cut alot cleaner.. maybe I just need a bigger plasma.. the best of them all is between 36.8ipm and 37.5 ipm..