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Post by prairieman on Mar 26, 2021 14:04:59 GMT
storm can you send or post a pic of how the DB25 board is wired up for you. I have the Hypertherm 45XP unit and have the machine interface cable kit with plugs into the back of the 45XP. There are 6 wires, that I have to choose from. Green/Black, Red/Black and Black/White. Per MR, the Red/Black arent used. What MR hasnt told me, yet, is which wires go into which slots or ports on the DB25. Any help is greatly appreciated. Thank you.
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Post by bLouChip on Mar 27, 2021 3:56:02 GMT
Today I have finally completed my MegaV Plasma/Router build, with many customizations to the unit structurally and to a much smaller extent, electrically. This build has been 8 weeks in the making, and with help from many sources and friends, but I want to thank Mill Right support for prompt and critical help and guidance when needed. I will post more information on my custom build in the next few days, with pictures and videos. I will likely open a separate thread/conversation since it deviates quite a bit from the norm, but certainly there are overlap areas of issue and solution as have been addressed here by storm and others. I spent most of today shaking down the system and running it through some paces, cut, interrupt, and restart scenarios, and calibration, most in mock up fashion with axis movements only, no actually cutting yet; tomorrow perhaps.
re. pairieman's question: I think I can address, although I don't have the Hypertherm 45XP, I have PrimeWeld Cut60, but it also has a CNC port similar to Hypertherm. According to Hypertherm's 45XP manual , pages 103 and 104 give the pin descriptions and pinouts for the CNC port on the back of the unit. Green/Black wires and corresponding pins (3,4) on their CNC connector are the ones you want to connect to the DB25 MR breakout board. Green/Black, described as "Start Plasma", triggers the plasma torch when connected through a switch or relay contacts. At the DB25 breakout board, the board terminal numbers are 14 and GND. However, I don't recommend you use GND, pick another unused pin on the DB25 board. I don't recommend that you connect ground (GND) from the MR Control Box to the trigger pins on your plasma cutter. The Hypertherm manual states that those trigger pins have 15VDC of open circuit voltage, I don't envision good things happening to the MR Control Box if you do that. Rather, I recommend that you get into the MR Control Box, and trace the DB25 pin 14 wire to it's opposite end, you will find it wired to a small relay board bolted to the side of the box. Unbolt the board and study it. You will see it has 5V+, GND, and Input on one end of the board, and terminals labeled NC, Comm, and NO or the other end. You should also find that a jumper wire ties Comm to GND. Not good. Remove the jumper to GND, however in doing so, in my board, the GND feed wire, which you must have on the board, also went to Comm, so move it to the opposite end of the board next to 5V+. GND is needed there with 5V+ to give power to the small circuit on the board which picks the relay (the small blue box). Just fyi, the Input pin/wire on the board is sourced by SPEN (Spindle Enable) from the Arduino controller. Also fyi, there is a green LED on the relay board which indicates power on/good to the board, and a red LED which indicates the Input is active, aka SPEN, aka the torch will fire.
So net: you'll want to use the NO (Normally Open) and Comm contacts of the relay board, neither of them being grounded in the MR Control Box. Change the wiring as need be to do that. Run the isolated Comm wire then to an unused pin on the DB25 board, and that pin, and original Pin 14, are the wires to connect to Hypertherm green/black, it doesn't matter which color goes where, it's just a switch, ungrounded.
I hope that helps. Some assembly required 
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Post by bLouChip on Mar 27, 2021 5:42:36 GMT
re. the plasma torch holder and usafpilot67 issues:
I also had some issues with the torch holder, but in general I believe it's a good design base, very compact and easy to modify and improve. The improvements I made cascaded into some Z plate modifications as well, and for other reasons. All the mods are described in this video:
and the purpose of the limit switch on the torch mount, the probe switch, is described also in the video:
Here is the gcode test file I ran today in trials as I dialed in the torch touch off coding, the probe coding. You are welcome to use as an example.
I hope this helps.
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Post by usafpilot67 on Mar 29, 2021 3:15:08 GMT
BLouChip,
Thank you for taking the time to post those videos. I am in my first week of trial and error on this machine. Each day I think I made a mistake and should have bought a crossfire pro for the same money but bigger table. I should have done more research. However I was under the impression from YouTube videos and advertising that the megaV plasma cutter as ready to go out of the box. I was wrong!
My approach is 3D printing because my first welder will be here tomorrow and I have a lot of practice to do before throwing down a bead on this machine. So, hopefully in a day or so I will have my 3D printed components done so I can post a picture of it. After seeing your video, I think I’m going to do magnets in my design as well. I don’t know if it’s worth it since I will never leave my table during any cut. But it would be nice if the torch cuts off during a moment of panic.
Also do you think the THC is a need for a machine that is 35x35?
I would be very interested in video or a quick picture of how you wired the prime weld 60 to the DB25. I had a hyperthem on order but that 10 week lead time had me researching. So I ended up getting the TIG 225 and the cut60 for a lot less than the hyperthem.
Thank you for the help,
Ken
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Post by usafpilot67 on Mar 29, 2021 14:29:09 GMT
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Post by bLouChip on Mar 31, 2021 4:46:02 GMT
Here's an update on my trials and tribulations with my MV Plasma custom build:
a) I have not cut steel yet  I'm stuck on debugging final issues.
b) the primary problem is EMF/noise entering the controller box and apparently knocking out the communications serial channel between Arduino and my computer. I suspect this because I see the Arduino RX/TX LEDs quit the rapid polling with UGS simultaneous to me issuing either M3 command or using the hand torch, pull the trigger. GRBL usually then goes into a delay action mode as if UGS and the UART chip are polling only every 10 seconds or so. The only recourse at this point is to pull the USB cord to kill power to Arduino board. I'm 99% sure the EMF is coming down the wire into the control box from the PrimeWeld Cut60 Start/Stop wire pair, which connects to the small relay board MR put in for Spindle Enable signal to trigger the torch. Another source of EMF is from the 1:50 divided arc voltage wire pair; that doesn't go into the controller box but it does run right down the outside and into the Promo THC SD unit which I stupidly mounted on the front of the controller box. I was second guessing my intentions on this move in the first place, but thought the convenience factor was just too sweet to have the THC right there, so I tried it. I was always prepared to move it. However, I wasn't prepared to see noise on the trigger wire.
c) I have a minor problem with my PlasmaDynUSA PTM60 machine torch in that it has a very strong electrode spring and long electrode blowback movement as compared to my TECMO PT60 hand torch. This means, any psi and arc voltage settings I can discover/learn from my hand torch do not translate to my machine torch. Also, I intend to cut a lot of 18 and 20ga. steel using 20amp tips at 50-55psi; can't do it with PlasmaDyn torch unless I crank to 65psi in order to fire the torch. Anyway, if I have to run at 65psi so be it. This is the least of my trouble. I only mention it because for a 1/2 day or so I didn't know if noise was my problem or a faulty machine torch because I had the 20amp tip on for the first practice cut and of course it didn't fire, for various reasons it now appears. I did this from experience of cutting 100+ linear feet of sheetmetal so far with the Cut60, 20amp tip, 50-55psi, while building the CNC. So net: to eliminate a bone head mistake like this for newbies (like me), I recommend NOT to get cute with tips and psi until you know the system works ! It will save you debug time. Just run a 1 or 1.1mm tip and crank the psi to 70 until you get the system wrung out, since a misfiring torch is not a fun problem to debug.
So net: I have tried a couple different shielded cables from the Cut60 to the controller box for the trigger wire (Start/Stop pins 1/2 on Cut60 CNC port), including the latest being cat5 cable where I grounded each of the 4 wires in the twisted pairs, basically using 4 wires for a 2 wire signal. No good. So I'm convinced I'm not getting an induced noise on the wire, rather it's coming down the wire as an errant signal from the Cut60; it's on the wire at the originating end; I'm basically jamming a radio antenna into the Arduino control box. It either has to be filtered off or separated by an isolation circuit, which the relay does, but not before the damn wire comes into the box. So I'll have to move the relay outside the box and away from the Arduino completely; I'm giving it the 6 feet COVID prevention/separation treatment. So as not to cause more EMF trouble, I'm going back to the DB25 pin terminal block, and IEEE cable that MR ships to get the signals to/from the THC and to the relay board. It's clunky, but I suspect MR has gotten their units working with it, so I'm in. And, those parallel printer cables have been around for 40 years or more, they have always been fairly EMF bullet proof, which is why MR ships them I suspect, that and there are probably still shit tons available for pennies in a warehouse somewhere in India since parallel printers are no where to be found now, this cable even pre-dates the China boom.
So that's it for now, what I have right now is maybe a CNC Plasma unit that looks cute, but no cut. Not good.
Someone asked about pics and pinouts for the Cut60. Pinouts are Pins 1/2 Start/Stop to the relay board NO/Com terminals, take the GND off Com as previously discussed (but hey, at this point, I'm not a model of success). The 1:50 divided voltage is pins 4/6, -/+, run to the divided arc voltage of the THC. The THC manual has the details, as does the Cut60 manual is Section 5. I'm happy to post pics and diagrams when I get this working, as in cutting steel.
Lastly, someone asked about Langmuir CNC and PrimeWeld Cut60 plasma cutter: I seriously considered Langmuir also, they seemed to have a well wrung out couple of CNC plasma units with a lot of customers. But they have proprietary software and controller, so it either works or they fix it OR it's a pile of steel . Mill Right on the other hand has a terrifically solid platform for milling soft metals, wood, and plasma; albeit on the plasma use case there are very few customers it appears. The controller and sw is open source, so anyone can tweak it in theory. But what sealed it for me was the 2 years of experience I had on CarveKing, the robust mechanical engineering evident in the system, and the excellent MR support when I needed it. And I wanted the milling and plasma functions. Even laser, which I have on the CK. I love it.
As for PrimeWeld - they are first class as well. Support 1000%. They answer email and phone. I have their MIG180, TIG225, and Cut60. I replaced a Lincoln Invertec V300 Pro with their MIG and TIG units, the Lincoln being an industrial scale welder, to which I didn't need 300amps anyway. It wouldn't surprise me after all this that PrimeWeld considers isolating the trigger wires for CNC use, but if not, I expect they will certainly update the manual to better explain the issue and how to mitigate it. Also, see this guy for anything plasma unit and consumables - www.georgesplasmacuttershop.com/ , I would have gotten my torch from him but he was out of stock for TECMO machine torches at the time. Don't f-around with the torch, get a TECMO or get one from George. |
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Post by bLouChip on Apr 1, 2021 1:23:57 GMT
Success ! My CNC system made the first cut on steel today!
The success was bitter sweet though, as it continued to fail due to EMI affecting the USB to UART communications channel in Arduino. I have a video of it here: www.youtube.com/watch?v=e0P3E3ob0Nc
I ran a few more cuts tests to determine when in the cut process the comms channel fails. I determine this by watching the TX/RX LEDs on the Arduino board, they typically fast poll with UGS when all working ok, when the polling stops or slows to just 1 per 10 seconds, then I know it's failed. Arduino/GRBL seems to remain in a useful loop executing any gcode that was in the buffer before comms failed, and any commands that make it to the buffer after failure in the once per 10 second polling. So in this case, comms failed when XY motion with the torch began, perhaps at the point when the arc transferred from pilot to steel / work lead. I believe at that point circuits internal to the plasma cutter switch over to high current for cutting, and i suspect a much stronger arc, and thus stronger EMI. I really need to speak to some experts about this, which I will do tomorrow. But first, as I shut down the shop for the eve to go have a few beers and rejoice on some success, I noticed I forgot to ground my CNC table. It's basically a grid antenna with all that steel. Early on this past weekend while debugging the EMI issues I took steps to drive a ground rod 3 feet into the ground just outside the shop door, and run welding work lead cable from the table to the ground stake. That did make some improvement in that I began to get more EMI repeatable results, if that's an improvement. Anyway, confer with experts tomorrow, I'll ground the table and try the test cut again.
So what got me to this point of making the first successful cut was:
a) the physical movement of the Proma THC SD to the other side of the CNC table. This action took the 1:50 divided arc voltage sense wire with it, away from the Arduino Control box.
b) I did not move the plasma trigger (Start/Stop) wire yet, just taking incremental steps, will do that tomorrow too. I hope that and/or forgetting to ground the table are the culprits remaining because that's about all I have left to apply. I've tried various types of shielded (and ensuring a chassis grounded shield) wire, twisted pair w one wire in the pair ground potential, splitting the 2 signals from plasma cutter into to separate shielded wire pairs, rearranging wires and harness bundles, capacitors (.1uf) on input wires. I have not tried any ferrite chokes on signal lines (don't have them but will look into the type needed and get some). All of these prior attempted mitigation fixes failing to make a significant difference, and observing the behavior of Arduino and the comms channel after a failure, all lead me to believe the issue is really with a dirty/noisy signal coming into the controller box from the plasma cutter trigger wire and arc voltage sense wire. The sense wire I understand was a long shot to have worked that way with the THC mounted on the control box, especially on a grossly unshielded control box as it is, so I was prepare to relocate it and I have. But the trigger wire irks me. That should be easy to filter or prevent through isolation at the plasma cutter, before every leaving the box. Anyway, tomorrow it gets relocated to the other side of the table with the THC, I built a platform to allow for it and the DB25 IEEE cable has the spare pins/wires for it. This move will entail putting the Arduino trigger relay board on the other side of the table, and in doing so I have to send +5v and Spindle Enable wires there also, but of course maximum shielding through the DB25 IEEE cable.
c) so speaking of the DB25 IEEE cable, I took extra precaution to wire one side of the connector bus to ground, so pins 1 - 13 are all daisy chain terminating in ground to chassis, as well as the GND pin. Now, this is not Arduino circuit ground, which actually comes from our computer USB cable, I don't connect the 2 grounds for fear of creating more problems, that shouldn't be necessary. If someone believes it is, please advise.
I added pics here of the relocated THC and the mounting panel.
d) I'm running a 1.1mm torch tip and 65psi, per advice from PlasmaDynUSA, so that problematic variable has been eliminated. Not f-ing around with cute cuts on 18ga sheet metal right now. Just demonstrate the system cuts.
More tomorrow. Cheers.
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Post by bLouChip on Apr 2, 2021 15:14:55 GMT
update: I moved the plasma trigger Arduino/controller box relay board to the other side of the CNC table, thus taking the EMI noisy plasma trigger wire with it and 4ft. away from my controller box. That was another major improvement ! I'm able to make some degree of back to back cuts now. Its not 100% yet, still plagued by EMI at times. The worst EMI moments seem to be coincident with times when the arc length is longest (3+mm) and strongest (highest amps and volts) which I believe makes electrical sense if I recall Electronics Tech studies 42 years ago So I'm living on the CNC plasma edge of success it seems. I'd like a cushion factor so as to not start accumulating a scrap steel yard. Now in theory those long & strong arc cases should occur never, certainly not desirable, but it seems to happens quit frequently when dialing in the CNC plasma system for the first few times, and more so when you factor in the THC and improper volt sensing setting. So with some luck today, and trying another perhaps improved machine torch (if construction and reputation mean anything - a PTM60 TECMO brand), I am optimistic the successful CNC plasma cuts will improve and multiply, where success is only defined as: cut through a small project without crashing the comms line and locking up the controller. A small "Hello World" sign comes to mind.
Btw, earth grounding the CNC table made a difference. Which reminds me, my computer sits on a steel roll-away cabinet, ungrounded, so I'll be grounding that today also, as well at back it away from the CNC table as far a reasonably possible. Without thinking of the computer, but of the comms line, I did change from a 4 ft USB cable to the short 1ft blue USB cable that Arduino comes with, knowing shorter is better in this case except for the fact of the metal roll-away cabinet that went with it closer to the table Duh!
Here's a couple of links to Hypertherm's recommendation for CNC EMI mitigation, its an interesting read.
Note there is signal wire recommendation of Belden 1800F given, which I may invest in for trigger wire and arc sense wire if all else fails. The only thing in the recommendations that I don't like, and won't do in the manner they suggest, is hard wire (bolt) my plasma cutter + work lead to the CNC table ground buss. Rather I have effectively connected the work lead to the earth ground table buss by way of a jumper cable clamp, so I have 2 clamps on my work material. That did make some improvement in stability of successive and successful cuts, thus some reduction in EMI. Doing it this way means I'm less likely to forget to clamp the work material with the actual plasma cutter work lead. Doing it per Hypertherm's recommendation means WHEN I do forget to clamp the work lead to my cut material THEN the up to 60amps of cut current will flow through other components of my CNC system that ARE grounded to the table earth ground buss. That won't be a good day. So, either don't do it, or do it with full knowledge of consequences when you DO forget to clamp the cut/work material.
Oh, one more thing - yet another CNC plasma / THC moment of discovery and experience in "don't do that !". Don't turn off soft limits when grbl throws an error that your next Z probe instruction will exceed soft limits. I got this error while making the video posted above. I thought, hum, not too surprised at that since THC is doing its Z movement thing and grbl doesn't know jack about it intercepting the z motor and related motion. In fact I was kind of expecting it some day. But it was odd that it didn't occur the 4 times I ran the job with plasma OFF, but because of the adrenal jubilation I was under at the time given the damn thing was actually making successive cuts in steel in a real job now, I didn't give it the thorough study the error condition demanded. I did however do the math of "well, where is Z now ? " both actually/physically where is Z on the rails and where does grbl think it is (based on DRO readings). The math checked ok, I thought, but apparently I forgot to add the movement amount that grbl actually complained about, not just "Is Z still on the rails and where does grbl think it is?" The move it's about to make matters too. So, thinking it was a fluke perhaps, I tried the job again after clearing the error as grbl suggested (but didn't home the machine), it failed again near the same line/cut in the job. I attributed this condition to the net sum total (+ and - Z) of the THC doing it's job after having made 5 or 6 full and partial job runs. Recall, when ever the THC take control of Z, and then gives it back to grbl, Z has lost it's precise zero. Those losses accumulate after scores of cuts. Could end up being neutral, +, or - of zero. But back to the lesson - I forgot I needed to re-home the system after each job (due to THC use), again the adrenal jubilation thing was going on full bore I suspect. So at this point, I think, "well, this must be normal for these CNC plasma THC setups" yeah. SO I turned off soft limits and ran the job again, confident there was plenty of Z movement to spare. So you guessed it, about that same point in the job, and I had stupidly turned away being more concerned with videoing the stupid thing and in my extended moments of jubilation now, AND only when I didn't hear the now normal pattern of torch touch off moves and arc/air pop to start a cut, did I turn back only to see Z trying to drive the torch through the work material and the Z plate bottom linear bearings half of the Z rails. The EPO was a handy item at that point, or it could have been the DOOR/breakaway button, I don't recall which one I pushed. So net: grbl was right on math, I was wrong. Only then did I take the time to do the math correctly. "Oh wait! What about the breakaway switch, why didn't that save the day you ask ?" "The Z axis must have driven the magnetic attached torch mount well up the Z plate during this limit boundary breach ? " It did. Well, that brings us back to some prior work a few days ago re my attempts to mitigate EMI by using capacitors on the DOOR/breakaway switch input circuit. I followed MRs prescription on CarveKing and put a 1uF cap on the switch, but in my case its a reed switch, not a limit switch with relatively high amp capacity contacts for a control circuit. Reed switches are significantly more delicate, they are meant to switch mA only. Well, basically I welded the contacts shut on the reed switch the first time it broke away days ago during that experiment, the capacitor discharged fairly strongly across the switch apparently. So in another adrenal stupid moment that day, I just cut the breakaway switch wire and continued to trouble shoot EMI issues elsewhere, thinking I'll replace the switch in a day or so when I get EMI sorted out. So the switch got replaced after this episode last night. I will say though that during trial movements, before EMI plague arrived, the breakaway switch did it's job several times when I wasn't purposely testing it. And the parallel switched push button on the control box for the same purpose has been a saving potential disaster after disaster, ever since I've been firing the plasma torch, it's the only way to kill the torch, although it's still reliant on the Ardrino/grbl to be looping correctly. Fortunately, the input pin that the DOOR circuit drives is programmed as an interrupt to the MPU, meaning errant EMI or other errant loops grbl may fall into are still likely to allow an interrupt line to get control, but not a guarantee. That, and all this trial and error with plasma firing and EMI debugging makes me consider putting a toggle switch on the trigger wire which fires the plasma; it would be a lot easier to disable plasma that way, between practice job runs and the real cut run, but that would be yet another mini antenna to either transmit or collect EMI in the system. I'll consider it though. So the moral of this episode is: don't turn off soft limits because of THC use, don't put 1uF caps on reed switches, don't cut wires that are meant for safety interlocks, and be mindful of your Z position when setting up to use a THC - give plenty of downward Z movement for THC to work with, the zero errors can accumulate. Oh yeah, don't forget to re-home (for benefit of Z) after each plasma job. I don't recall there being a way to just re-home (machine home, not WCS home) one axis, but if there is, someone please advise.
Here's a video of the self induced failure mode when the operator disables soft limits in the scenario described above... Notice at the end of the video the Z plate is literally "coming off the rails". Near disaster. It recovered well, and I don't think I lost any linear bearing ball bearings (about 1mm dia. little guys).
Cheers,
Lou
THC panel pic updated with plasma trigger relay board on it.
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Post by bLouChip on Apr 3, 2021 14:54:27 GMT
update: EMI issues appear to be 100% mitigated and the system seems 100% reliable and repeatable now ! Holy Cow! What a haul this has been !
Here's the final fix: Buy a Tecmo brand PTM60 torch ! Don't f-around, buy Tecmo. (or buy big and go Hypertherm of course) But if you buy a different brand or custom make, I recommend to use coaxial cable for the torch lead, which is what Tecmo does. Not the TV/Internet coaxial cable, that stuff isn't 60amp capable; this application needs kilowatt capacity, probably 10kw? coaxial cable. George would know. 60amp x 100volts = 6000watts, then double it for initial surge since open circuit plasma voltage is 200+volts.
The PrimeWeld Cut60 is an excellent choice of plasma cutter for the price, with or without CNC use. Customer support is second to none. The signal wires are noisy, but that's fixable as I described in the previous posts. The machine torch is your choice, make a good one, make a shielded purchasing decision on the torch and signal wire cables.
MillRight Mega V is an excellent choice of multi-purpose CNC, perhaps the only choice in the hobby/small biz price range; it does it all: router/laser/plasma. Same as PW, first class/excellent customer support. But the control box and wires are not well shielded. But its fixable for plasma use cases as described in my previous posts. For non plasma use cases, it's fine as is. For plasma use cases it may be fine with well shielded machine torch and signal wires, which I suspect Hypertherm units are, they better be for north of $4,000 for 60amp. IMHO.
So I ran about 15 minutes of total cut time on the Tecmo torch and NOT ONE EMI issue. Not one of any issues for that matter. Certainly more reliability testing to do yet, but the outlook seems very positive.
The prior EMI mitigation measures were absolutely necessary, and there are more measures that could be taken if reliability falls off for any reason. EMI is a fickle thing. The best analogy I can think of is, recall back in the day when cars and trucks had longer spark plug wires, and 8 of them, and someday your pulling a load down the road and you begin to hear radio static, aka interference; maybe your engine begins to miss too. The symptoms come and go, maybe humid days its worse, maybe not, climbing a hilly road or not. Well the fix was, if you recall, get a known good plug wire and one by one swap it out with a cylinder wire, including the distributor wire, test drive the vehicle under load each time you swap a wire, and eventually you find the bad wire, and the radio sounds fine again, and if your engine was missing, now it's not. Also, if you've ever replaced your car radio or looked under the dash, you noticed the radio is encased in a steel box, and the antenna wire has a very positive friction fitting nickle tinted plug end as it mates to the radio port. The steel case is EMI shielding. The nickle plated friction fit plug is to ensure a good electrical fit to the EMI shielded antenna cable (ah- coaxial cable hum) and so on. EMI is a fickle thing. And even with all that shielding, a long bad spark plug wire (an arcing high voltage high amperage wire, hum, kinda like a plasma lead and torch head) can ruin a good song
So todays video is the first 2:27 mins of run/cut time with my new friend Tecmo PTM60. Enjoy ! I did ! A shout-out again to PrimeWeld, big thank you for providing the PTM60 !
Going forward in this forum, I will open a new thread to get into describing the Mega V custom build that I did, and the use of LightBurn Software for quick and easy graphic and light engineering design and gcode generation for plasma use. LB is a CNC laser graphic editor, gcode generator, and CNC gcode sender, there is no need for UGS in cases of laser. In order to adapt it to plasma use, I post process the gcode to insert the Z axis torch touchoff to set ITH, pierce delay, and retract commands. During the cut, Proma THC SD takes over to control torch height. Then repeat for next cut, etc. For now, I do use UGS to send the gcode, only because UGS gives me more macro power, more CNC feedback and control, file editing, and I have to post process the gcode anyway. LB does have a before job and after job user gcode block I can define, and I intend to test my torch touch off and retract gcode via this method any day now. I'm also encouraging LB to add a feature for user defined gcode blocks applicable to each move and shape cut for plasma use case, rather than just once at the begin/end of job. For plasma use case, torch touch off as you know has to be done every time the M3 / M5 commands are issued.
more later, I'm continuing my celebration today with more cigars and Michter's bourbon... Cheers, Lou
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storm
New Member
Posts: 18
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Post by storm on Apr 8, 2021 0:36:07 GMT
Hey guys. My Plasma Machine is up and running and cutting parts GREAT!.
I wish I could say its all Millright... For the price we all paid for the Mega V Plasma it should work out of the box...
Not even close. My experience with the Millright customer service was terrible.
I love the Mega V for wood, I think it is a great robust design and the controller is adequate.
What I found is the control board is just not directly compatible with any software that I could find to operate a plasma system. So you are stuck trying to come up with work-a-rounds and trying to force some software to do what you need.
I have the Hypertherm 45xp and after Months of trying to get the millright controller to work, I finally just bought a completely new controller set up. Spent just about $1000 but it has a built in THC and works GREAT.
Bought the PROMA control board. about $450, not bad considering the Proma THC you need if you are going to try to keep the millright controller was like $350.
YES you NEED a THC, as soon as the metal heats and warps the THC adjusts the height to keep the cut clean and keep from crashing.
The software that comes with the Proma controller board works just fine and comes with free with the controller board. I wouldn't recommend for heavy production work. I find it is accurate and super easy to use. You can download any dxf file. I design in Rhino and export the dxf into the proma software for cutting.
Also customer service is amazing, you call on a Sunday afternoon and a real person answers the phone, speaks English, will remote into your system and diagnose any issue.
If you want to save yourself months of never ending frustration, look into new control hardware that is compatible with software designed to run a plasma system.
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storm
New Member
Posts: 18
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Post by storm on Apr 8, 2021 12:29:24 GMT
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Post by bLouChip on Apr 11, 2021 17:10:14 GMT
Storm: good to hear you have plasma success ! That was drastic, but whatever it takes, well done.
Now - an update on my case for those sticking with the MR black box for now... My plasma cutting success last weekend was short lived I'm sad to report, which explains my delay in getting my MVP Custom Build thread opened in this forum. I did enjoy about 30 total minutes of plasma cutting over multiple job runs, where the design (via Lightburn sw), gcode save, plasma gcode post process, and UGS send/run did work very smooth and well. That was nice. However, mid week or so, after I took a few days off from the mayhem of CNC build, to celebrate no less, I returned to the shop to "pretty up" some things and add a toggle switch to the plasma trigger wire on the plasma/THC panel mounted opposite side of the table from the control box. The toggle switch has the function of "Plasma Arming ON/OFF"; its simply in series with the Arduino relay board plasma trigger N/O contacts; so in order for the plasma torch to fire, I need an M3 command (to pick the relay) AND the Plasma Arming switch ON. This allows me to make easy dry runs of the cut path without having to either comment out M3s or walk over to turn off the plasma cutter. There are also benefits to this Plasma Arming switch when dialing in cut settings, and when cuts go bad. So after this seemingly simple mod, and wire tying up the D25 cable to the cross table strut, and after making some torch touch off probe code changes to improve the cut performance/result, I was unpleasantly surprised that EMI/RFI had reared it's ugly head again and was consistently knocking out my communication line to Arduino again ! I spent a few hours making a new trigger and v sense wire between the plasma/THC panel and the plasma cutter, going from CAT5 cable to shielded twisted pair, but that didn't solve the problem. I also double checked GND and discovered that the DC- (negative) powering the Arduino board was not chassis GND, it was floating. This also means the short USB pigtail in the control box had a floating shield. So I grounded the DC-, but it only gave minor improvement in that I could dry fire the torch next to the control box without interference with the comms line, however once it began cutting steel with high current, the party ended; every time. I attributed the new EMI/RFI problem to a longer arc / higher pierce height, longer pierce delay, and longer delay in the THC to control the cut height. Those adjustments are simply needed to improve cut results. So on to the next level of EMI/RFI mitigation... I ordered ferrite chokes, faraday cloth, and an EMI/RFI meter; I get delivery today, so we'll see.
It didn't occur to me that I'd wired tied to a higher position the D25 cable until I was discussing my problems and mitigation ideas with an engineering friend, and he noticed the cable and commented "... that looks like it could be a nice RFI antenna!". TO which I think I said - "Oh Shxx!". Prior position of that cable, when the system last worked, was that it was slung low below the cutting surface plane as it ran between the control box and the plasma/THC panel. Either way its a potential antenna, but in 'line of sight' to the plasma cutting arc is going to expose it to more RFI mW than if its slung below the cutting surface plane. I was counting on the cable being well shielded which it is, and every other pin being GND which it is, on being adequate protection, but perhaps not. Anyway, golf and The Masters has gotten into the way of more testing recently, so later today I'll proceed with testing and EMI/EFI mitigation efforts yet again, which will be cumulative and in this order with testing between each:
* remove D25 cable from chassis mount and let sling low below table top plane
* ferrite choke installs on D25 cable, plasma sense and trigger wires, and USB line for starters
* faraday bag over control box and plasma / THC remote panel
* faraday sleeve over plasma sense and trigger wires
* faraday sleeve over D25 cable
* faraday sleeve over USB cable
* ferrite chokes on other sense wires running into control box * change USB serial comms baud rate from 115Kb/s to 9.6kb/s (drastic, requires recompile of GRBL) * USB opto isolation circuit between my computer and control box.
* dynamite
later.
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Post by bLouChip on Apr 12, 2021 3:17:33 GMT
update: It Works Again!! We're cut'n steel !
The fix: attach ferrite chokes to noisy wires ! I installed 3 chokes: 1 on the D25 cable nearest the control box, 1 on the two wire pairs from the plasma cutter nearest the plasma/THC panel, and 1 on the THC input/output Z signal lines nearest the THC. See photos below. I also lowered the D25 cable but alone that was not a complete solution, it took the ferrite chokes to get me over the top of the EMI/RFI issues. I believe I'm still live'in on the edge so I will apply more chokes on other wires as a precaution, and continue to test. I also still have faraday cloth to apply if necessary. I did not do extensive testing/cutting, but I did get 20 mins in without any issues once if began to work. The gcode parameter adjustments on the torch touch off, pierce height, initial torch height, pierce delay, and THC delay all worked well and produced excellent cuts on 18ga mild steel; nearly zero dross; the only dross being on the bottom side and always near the pierce point, most likely due to the lead in of only 3mm being too short by .5 to 1mm or so. The cut project was a 5in. x 5in. FF maltese cross with graphics and letters inside, so fairly small dimensions to work with considering lead ins. I used a 30amp tip @ 30amps setting, 55PSI, F2500mm/min cut speed, THC 50V (~1.5mm standoff), pierce height 3.2mm, ITH 1.7mm, pierce delay 1.25sec, THC delay 1.5sec, THC Z speed 70mm/min.
Well, I'm happy with it, and confident I can overcome other EMI/RFI issues if they crop up. Making use of ferrite chokes on input wires is basic EMI/RFI mitigation, and I should have taken that step weeks ago, I just forgot to order them until I got into this debug cycle, and then I kept finding unshielded wires or poorly shielded wires, missing GNDs, and obvious noisy signals from the plasma cutter; so I chased other basic stuff perhaps too much. In retrospect, I would not be surprised if the system were to work with the original unshielded torch lead once all mitigation measures are implemented. Most of the EMI/EFI comes from the torch arc in the first place, and I lengthened it by 1mm on the pierce height since last week's success, so shielded signal and comms wires with grounded shields and ferrite chokes are a must, as well as table earth ground.
btw - the Lightburn sw, with gcode save, gcode post process with VIM macro, and UGS send worked great ! I was able to design and cut the FF maltese cross in just 30 mins; and cycle time to make a change is about 1 min. Awesome ! I've made a video of the process and will post in the other thread.
Cheers ! Of course this repeat success warranted another evening of toasting with Michter's bourbon
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I'm stuck on debugging final issues. 
