No Arc. Understanding 4 Relay Module + Proma THC.

[AuMogul]

I recently picked up a used Delusional Design CNC table. The first owner couldn't get it working and noted that the owners of Delusional Design were less than helfpul; I'm having a little more success on my own, but I am hung up on the THC and relay switches. I can get a drawing to G-code from SheetCam, and get the G-code to play from UGS. I've followed the actual code from the G-code file while it's running, line by line. The code gets hung up when the torch is switched on. I get no arc and the G-code stops, and the machine disconnects from UGS ( I can hear the USB disconnecting through the PC). At the point of failure I can also hear the relay switches clicking.

I mapped out a diagram for some of the wiring & jumpers involved with the 4 Relay Module, Plasma Connector, and the Proma THC SD. I am trying to narrow down the cause. Does anybody see anything out of the ordinary? The system is run off an Arduino UNO, CNC Shield BOB, 4 Relay Module High/Low Level Trigger board, and Proma Compact THC SD. All the pictures in the diagram are exactly what is in the CNC. Thanks for any comment even if you are looking for help too.

[djreiswig]

What plasma cutter are you using? Might be an electrical interference problem.

[AuMogul]

I've got a Lotos LTPDC2000D Non-Touch Pilot Arc. The previous owner was trying to get it to work with a Thermal Dynamics Cut Master 52. I realize the cutters are different animals. I wanted to make sure all the wiring was looking proper in my setup before moving on to trying to get the Lotos going.

I feel like the table was built DIY from a kit because some things were outta place that I had to fix. I'm wondering if the wiring is completed on the same level. I'm more concerned how the relays are wired with the THC. If they look to be right.

[robertspark]

Lotos LTPDC2000D..... High frequency start.... + Running Arduino..with usb communication interfaces .... That just has pain written all over it with many hours of trying to figure out why it cuts random or stops....

[AuMogul]

Thanks for the opinion. I'm definitely experiencing that. I came from alot of 3D printing and design plus welding as a hobby, just trying to branch into more welding fabrication. SO your input is appreciated on how to best setup this table. Before I throw more time in this setup ( I'm guessing the boards in this Delusional Design CNC all amount to the cost of $50 or less) , is there an alternative boards/interface that would be worth looking at? I can do the reading just need some ideas/names of what to look for. I see a lot of Arduino setups, obviously because they are cheap and accessible.

[robertspark]

Probably the best way to go + cheapest is using LinuxCNC, but you need to install linux on a pc.... so if you only have or want to have one PC (or you only have a laptop then I would recommend UCCNC. I will detail both below.

Given I know little about your setup other than the photo below it appears that the arduino has a shield for 4 stepper drivers so the costs now will begin to rise.....

LinuxCNC + Plasmac
http://linuxcnc.org/docs/devel/html/pla ... guide.html

There is an active + helpful forum here https://forum.linuxcnc.org/plasmac who will help you through any issues / questions you may have (I have installed it a few times but don't use it as I like windows too much.... + uccnc meets my needs + I have all the other hardware [sunk cost effect] .... but I have the Mesa hardware too so go figure....
You will need some Mesa hardware:
1) a Mesa 7i96 (essentially an ethernet motion controller.... but the linux crowd get upset with calling it a motion controller.... but it controls the motion and it gets and sends information back and forth to the pc via ethernet)
http://store.mesanet.com/index.php?rout ... uct_id=311
2) a Torch Height Control Module (choose the voltage range your require as they provide 0-300V, 0-10V and 0-5V.... plus you can add resistors to change (increase the voltage range if you require too).
http://store.mesanet.com/index.php?rout ... path=69_72

A couple of things with linuxcnc.... a PC is generally recommended but if does not need to be the latest and greatest... in fact a little older tends to be better in my opinion as the drivers will be available and you are unlikley to get any install issues which you may have if you installed the latest greatest and super fastest motherboard with graphics card etc...

a laptop is not recommended because of power saving features which can throttle its performance and put it into a sleep / slow down mode.

I am fairly sure you could run a raspberry pi, beaglebone, ASUS tinkerboard or some other mini minicontroller compatible with linux but you'll need to figure out linuxcnc with it given its set up for the X86 or amd64 chipsets (bit more hard work if you ask me....)


UCCNC
For windows that will run on a pc or laptop (I run a fanless PC) no problems I would recommend uccnc.... it is slightly below the cost of buying mesa hardware.... buy you will need a torch height controller which will add another $250 odd to buying a decent one (come to that later)
https://cncdrive.com/UCCNC.html
install the Development release as it provides all the newer features but may have the occasional bug.... if time is money then install the stable release which should have zero issues.

you will need cncDrive hardware (mothon controllers) as uccnc will only work with cncdrive motion controllers... you need to buy a licence with is locked to the hardware serial number you buy.
UC100 https://cncdrive.com/UC100.html (I don't recommend as its USB and USB does not like electrical noise but many run them just fine)
UC400ETH https://cncdrive.com/UC400ETH.html
UC300ETH https://cncdrive.com/UC300ETH.html
AXBB-E (best value as you don't need a breakout board and it is 24v compatible or I/O''s) https://cncdrive.com/AXBB.html

You will need a torch height controller...
I use one of these and am happy with it as a lower cost solution https://minithc.com/
Many on here seem to run one of these and are happy with it too https://www.pricecnc.com/product-page/avhc10


General Hardware you may need....
Given it looks like you have an arduino shield with stepper motor modules that can be installed into it..... you will probably need some stepper motor drivers.... these could be expensive ..... but it depends what you want to go with.
I use Leadshine AM882H drives (you feed them AC and set them up with software and they do the rest.... no longer made but can still be bought second hand from china)
Lost of people like gecko drives...https://www.geckodrive.com/stepper-motor-controls.html .. they were too expensive for me in the UK at the time I build my machine.
There are a million other stepper drive options....

Be careful with TB6600's and TB6560's as they don't like back emf and don't like to be run near their voltage rating.... but you pay for what you get at $5/drive.... buy two and have spares when you need them....

Power supplies.... probably a 24v supply for the mesa / AXBB-E and also a power supply for the stepper motors


PS: before you ask.... nope I don't work for any of the above companies, and nor have I got a discount from any of them and could not be bothered what you buy as I'm not on commission..... (but I have a box full of solutions that didn't work / work very well )

[robertspark]

the upgrade should not cost you $900 (especially if you useTB6600 drives! at $5 a pop!)

+ they are using uccnc...
http://www.delusionaldesignscnc.com/sto ... ne%29.html

stateside you can buy uccnc + cncdrive motion controllers here:
https://www.cnc4pc.com/motion-control/m ... ucx00.html

[Rodw]

Robert's given a very good summary of your options. On balance with a proma , hf machine and coming from Arduino, I would suggest Linuxcnc and a Mesa 7i96 ethernet card $119 and the Plasmac config. You can keep your Proma and use it with Plasmac but another $69 for a Mesa THCAD-10 voltage to frequency card is not that much more and will give you a better system. DO NOT get a THCAD-300 with a HF start machine. It will go up in smoke!

You'll need 5v logic and 24 V field power power supplies (2 amps is heaps) You will lend up with something like this:

7i96.jpg

Mesa 7i96, and THCAD-10 for torch voltage and THCAD-5 for ohmic sensing. Be sure to buy the Mesa DIN rail mounts and their common connector which as 2 banks of 12 common terminal (to the right of 7i96) as that makes life very easy in a super compact form factor.

The reason why I suggest this path is the PC will be galvanically isolated from the HF noise via the ethernet cable and there will be plenty of that!

As far as stepper drivers go I would skip the TB6600's. I've had a good run out of Longs Motors DM542A and a 48 volt power supply with Mesa hardware but as Robert says, you can spend a little or a lot. I'm in the process of upgrading to Italian made Lam Technologies drivers at AUD $350 a pop. DO not be tempted to get an all in one solution like Gecko 540 or Leadshine. There are quite a few gotchas with Geckos and Linuxcnc so i'd not suggest them.

Hope that helps.

[robertspark]

I'm in the process of upgrading to Italian made Lam Technologies drivers at AUD $350 a pop. D

curious why? would a servo upgrade not be better?

what is the advantage

DO not be tempted to get an all in one solution like Gecko 540 or Leadshine.

+1 avoid IMO, you are way better off with individual drives and not using an all in one solution like these (sure they work, but a lot of people have setup issues with them)
https://www.zappautomation.co.uk/mx4660 ... river.html
https://www.geckodrive.com/g540-4-axis- ... drive.html

[robertspark]

it is probably also being aware of solutions such as these stand alone / integrated ones too (I have never used them so cannot comment on their function but at least one user on here has provided a review of the myplasm system)
https://www.proma-elektronika.com/myplasm-cnc-system/
viewtopic.php?f=3&t=30045&p=182382&hili ... sm#p182382

there is also the masso which is Australian made, but IMO very expensive but limited in I/O's and seem to run on a similar principle to the HICON (for mach3/4) with things being an extra module that you pay for to enable
https://www.masso.com.au/product/cnc-pl ... roller-g3/
https://www.masso.com.au/product-catego ... echnology/

wirth these all in one solutions adding other things later may not be possible such as an air scribe, router, drill, whatever..... where as uccnc and linuxcnc can be made to do other things as well and are expandable

[Rodw]

I'm in the process of upgrading to Italian made Lam Technologies drivers at AUD $350 a pop. D

curious why? would a servo upgrade not be better?
what is the advantage

I just outlined the argument for steppers on this thread
viewtopic.php?f=3&t=30490

Some of the cost is offset by using AC drivers eliminating a rectification step so a 65 volt AC toroid can be connected to the drivers which will then output approx 90 volts to the drives (or a 32 volt toroid to give about 50 volts to the motor).

And yes Linuxcnc's plasmac supports engravers and plasma hole spotting out of the box. Adding drills and other tools becomes trivial because of Linuxcnc's support for multispindle machines so a different spindle can be selected by modified M3 & M5 commands and loading the appropriate tool from the tool file to set the offsets.

[robertspark]

Some of the cost is offset by using AC drivers eliminating a rectification step so a 65 volt AC toroid can be connected to the drivers which will then output approx 90 volts to the drives (or a 32 volt toroid to give about 50 volts to the motor).

That is what I do with my leadshine AM882H (must be "H") drivers..... I just feed them 50v AC out of the toroidal transformer avoiding a bridge rectifier, but more importantly smoothing capacitors too... effectivly they are operating at 70vDC

the drives will handle 8.2A

[AuMogul]

Thank you thank you @Robertspark and @Rodw. You guys have given me plenty to pour over and learn from. I've been going the rounds with what I have already, and it's no wonder the guy before gave up. I have an old PC running the setup already so I am a step in the right direction already. I did have an even older machine running Linux Mint for fun around, but I am not sure I have that system anymore. I'm hoping to get some type of work around going so I can get some cuts started and move in the right direction of upgrading all the components so I have a more stable machine.

I thought about bypassing/eliminating the THC for the time being and seeing if that works. Basically in my photo is all the components in the system, plus an Arduino UNO which the CNC Shield board piggy backs to AND the stepper motor drivers plugged into the CNC Shield for each axis, X has two. I can get more detailed pics of the actual setup as I push on. It's been such a headache... I was bit flabbergasted as I've learned the internal components maybe cost $25 for a 4 relay, CNC shield, stepper motor drivers, and Arduino UNO... Ugh. Talk about raking in some profit at Delusional Design.

[robertspark]

Note I do not know GRBL or the arduino code that this board is running or how you issue it to the board....

But it looks like the wiring is actually correct (ok its all running at 5Volt logic) ..... but it's likley to run though...

M3 "should" turn the torch on and M4 should turn it off, given it is using the spindle direction signal out of the shield.... so the spindle has to change direction to turn it off (I am not sure about M5 working as M5 does not normally change the direction of a DIR signal..... it just stops movement.

The THC is "probably" enabled with M7 and disabled with an M9

If you give me a link to the code I can try to advise better

If you take some photos of the stepper motors or any numbers on them I can probably find the specs (current ratings)

It may be possible to run TMC2209 stepper motor drivers which are 2Amp rms and can give better step accuracy (I use them on my 3D printer but with Marlin...... so I have no idea what code that arduino you have is running).

None of this will fix in my opinion your underlying issue which is likely to be high frequency start with a Lotos LTPDC2000D Non-Touch Pilot Arc plasma cutter though.... so you may still get issues... who knows...

[AuMogul]

The Arduino is definitely running GRBL. And you are correct the torch on appears to be M3S1000 and M3S0 is torch off. I read through the post processing file made for the machine, and few other process files to try and sort out what's going on. Mind you, I'm learning how it all melds (software, hardware, GRBL, UGS, SheetCam, etc) together so I can pin point issues. I have zipped them into a file and provided a link to them at the bottom here. I see a "macros" file that was included in their download that references "thc off" M4. I am uncertain what the "macros" file is for. I used the post process file in UGS which seemed to create a gcode with no problems. There are references in the ...freedom series.scpost file that references some THC on and off codes. However the THC on code is the same as the Torch on code, so I'm not sure where I go from there. You have a wealth of knowledge on this and I am grateful for your help. Thank you-

ddcnc process files: https://share.value.bz/s/NWH56DHWTQaFf9P

[robertspark]

The "MACROS" file lists out all your gcodes

Code: Select all

[
  {
    "name": "M3",
    "description": "torch on",
    "gcode": "M3 S1000"
  },
  {
    "name": "M4",
    "description": "thc off",
    "gcode": "M4"
  },
  {
    "name": "M5",
    "description": "torch off",
    "gcode": "M3 S0"
  },
  {
    "name": "M8",
    "description": "spindle on",
    "gcode": "M8"
  },
  {
    "name": "M9",
    "description": "spindlle off",
    "gcode": "M9"
  },
  {
    "name": "probe z",
    "description": "Milling probe",
    "gcode": "G91;G38.2  Z-500 F700 ;G92 Z19;G90"
  },
  {
    "name": "home and goto zero,zero",
    "gcode": "$h ;G90;G20;G92 x0 y0 z0;g0 x-50 y0.55 z-3;G92 X0 Y0 Z0;"
  },
  {
    "name": "goto 48,48",
    "description": "",
    "gcode": "G0 X48 Y48"
  },
  {
    "name": "goto 0,0",
    "gcode": "G0 X0 Y0"
  }
]

the DD CNC_mm.pp file is the Vectric Post Processor file (only useful if you use vectric to do your post processing to generate gcode).

The *.scpost and *.tools are both sheetcam files (two of each file) one pair for milling and the other for plasma.
Both of which can be loaded into sheetcam.

...You have a wealth of knowledge on this and I am grateful for your help. ...

No, I know very little just always learning something new, I get it wrong regularly but its easier to be wrong when there is only once chance of being right about something....

[AuMogul]

I found a thread in my search of some talk about using a High Frequency (HF) plasma cutter with a CNC. There was one really good reply by Jim Colt on it being possible to do so with a long list of measures to be taken. After looking through it and understanding better the implications of trying to use a HF cutter I am thinking I would rather look for an alternative plasma cutter that is blowback non-HF pilot arc. Is there an inexpensive unit out there that doesn't break the bank and has ready to play connections for CNC? I did see this "HeroCut HC6000 220v 60Amps Non-HF Blowback Pilot Arc Non-Touch " unit which may be a good place to start learning with. I figure I will sell the Lotos I picked up and put it towards a proper cutter. It would save me time to do it this way over modifying everything on the CNC, wiring, PC, grounding, etc to work with a HF cutter.

Here is the reply and the source in case anybody else is looking for the same answers.:

******QUOTE:
I can pretty much guarantee you can make almost any machine work with a high frequency plasma. Here are a few things you would need to consider doing:

1. All motor and drive related leads need full shilding and twisted pair connectors. The shields should all be connected back to a star ground point at the driven ground rod.
2. Torch leads need to be shielded (outer cover with braided metal shield) that should be grounded only at the high frequency generator end.....back to the star ground point. The rest of the leads must be isolated from any machine metalic parts....preferably inside a plastic non conductive powertrack.
3. Chassis of plasma power supply (with high frequency generator should be mounted away (as far as practically possible) from the PC, and should be grounded directly to the star ground point.
4. PC should be as far away from the plasma power supply, should get its AC sourced through an uninteruptible power supply with surge protection. PC chassis should be grounded directly to the star ground point.
5. If a remote wired pendant is used, it should have a shielded cable, also grounded to the star ground point.
6. The gantry of the cutting machine should be grounded to the star ground point.
7. The torch carriage and z axis slide should be grounded to the star ground.
8. The computer monitor should be connected to the computer with a shielded cable. The mousealso needs to be shielded.
9. There should be some sort of optical isolation between the plasm I/O and the control box for the I/O.

Note, each ground wire to the star ground needs to be separate.....no "daisy chaining" as this can create ground loops.

The work ground from the plasma should be bolted directly to the star ground (no welding clamp)

The cutting slat bed should be connected directly to the star ground as well.

The star ground point should be right on the ground rod, or within about 6 feet, any extra cable length should be shortened, no cables on the machine should have any coiled extra length.

This is the minimum that should be done on any cnc installation with a high frequency plasma.....this often, but not always, eliminates electrical noise interference problems!

I have worked with these issues for many years in the field. There were a few installations where we never completely solved the noise issues.

On the latest technology industrial machines the plasma and motion connections to the cnc control consist of 2 small fiber optics cables as well as a single ethernet connection.....there are no longer any noise issues with this setup!

Jim Colt Hypertherm
****** END QUOTE

source: https://www.cnczone.com/forums/general- ... 6-cnc.html

[robertspark]

There are a few blowback start machines about, the easiest way to find them is actually to look at the torch

http://www.trafimet.com/plasma-cutting- ... ing-torch/

Find one with a trafirmet "S" torch and it will be blowback start.... Or uses the same consumables as the trafirmet S range (I think they are well copied and available from China)

[Rodw]

I don't think you can buy any torch and plug it in to a random plasma cutter.

I have always maintained CNC plasma cutting is not a cheap sport. One thing I've learnt after having owned 3 plasma cutters (well 4 counting the one we tried to repair that exploded in a cloud of smoke) and only one table is that you get what you pay for. I've seen so many people try to get entry level machines going with lots of headaches. I don't have experience with the herocut but I think thats the barest minimum machine. The next up is probably the Everlast 50s (which I've owned). It has its problems but you can make it work. At least it has a CNC interface and a blowback torch. I think Longevity has something similar. From there you leap up to Thermal Dynamics, ESAB and Hypertherm. These days I have a Thermal Dynamics A120 and all I can say is its streets ahead in build quality than the Everlast and there is real value in having cut charts.

[robertspark]

No you cannot plug a blowback torch into a random plasma cutter.

But if you look at them for sale sometimes you will see them using trafirmet "S" torches.

trafirmet make plasma, mig and Tig torches plus consumables.... That is all they do... (I don't believe they make plasma cutters, or mig or Tig welders)...their torches get used by a number of manufacturers

There are some nearby Italian plasma mig and Tig machine manufacturers close to the trafirmet factory in Italy though.

I do believe you pay for what you get here (good quality operator and service manuals and also detailed cut charts) and getting a good one would be an investment.... But it depends on what you want to use it for in the long run..... Occasional use or churning sheets of steel out daily.

I came close to buying a much cheaper (than hypertherm) plasma cutter which was 40amp and used blowback start with a trafirmet torch.... But it did not have a manual to speak of and it's duty cycle was very low 40% at 40a from memory (I run from a single phase 230v domestic (house) supply) so am limited to single phase.... It would have just been possible to use a us sold (CSA) hypertherm 65 on single phase but it was probably going to be a stretch on the domestic supply plus if I move house with a compressor running etc too.... Plus I've not been asked to do any armour plating recently...

Duty cycle is important if you are doing lots of cutting or big cuts given it could be very annoying if the machine decides it needs to cool it's self down and has exceeded it's duty cycle and just stops cutting.... A 40% duty cycle normally means cutting continuously for 4 mins with 6 mins to cool down in a 10 min cycle. Ambient temperature can affect this too... Cutting in 40 Deg C will be very different to -5 Deg C. Some manufacturers may over rate their data using these sorts of tactics

[AuMogul]

So far the Everlast Powerplasma 52i has been the best looking unit: https://www.everlastgenerators.com/prod ... plasma-50s

This company has the most comprehensive documentation and information to find about the unit. QUESTION: Are these types of "CNC Ports" wired in a universal configuration? From the few configurations I've seen, they all look to be wired differently.

SEE ATTACHED: screenshot of powerplasma 52i manual, page with CNC port description.

[robertspark]

QUESTION: Are these types of "CNC Ports" wired in a universal configuration?

no, but some manufacturers share the AMP / TYCO CPC (circular plastic connector), which is a 14 pin connector and not the 12 pin shown below:

Plug Shell Part Numbers: 206044-1 / A1358-ND
Cable Clamp Part Numbers: 206070-8 / A32516-ND
Pins Part Numbers: 164164-1 / A99521-ND

[Rodw]

The Everlast uses a Weipu 12 pin connector. You should find it on ebay or aliexpress.
Be sure to read this thread
viewtopic.php?f=111&t=23700&p=181019

The other gotcha is that the internal AcOK relay needs a minimum current (100 mA from memory) to turn on and if your hardware draws less current than that, you can get oxidisation of the relay contacts which results in intermittent operation over time. The fix to this is that you can add a pull up or pull down resistor depending on your hardware. The required value will very between THC's. a 1k 1W resistor worked for me. I've kept that resistor in place for my TD A120

If you decide to go with Linuxcnc, a THCAD-10 with no scaling resistor and setting the Everlast board to run a 16:1 divider and configuring Linuxcnc to expect a 24:1 divider is perfect. If you have a Proma or something that expects a 50:1 divider, bridging the board as shown in the above thread seems the way to go.

Don't let my experience put you off. Its not a bad machine once you get this all sorted out. Particularly if you can source the machine torch mentioned on that thread.

[AuMogul]

The other gotcha is that the internal AcOK relay needs a minimum current (100 mA from memory) to turn on and if your hardware draws less current than that, you can get oxidisation of the relay contacts which results in intermittent operation over time. The fix to this is that you can add a pull up or pull down resistor depending on your hardware. The required value will very between THC's. a 1k 1W resistor worked for me. I've kept that resistor in place for my TD A120

This is next level experience for me that I don't understand fully. How do I test the ACOK relay for minimum current? Do I multi-meter test when the plasma is activated? Connect leads to the proper connector out pins at the CNC port on back? Thanks for the heads up. The Everlast 52i arrives today and I was able to sell of my Lotos ; so I'm excited to get it configured.

[AuMogul]

UPDATE: Received the shipment today. To my surprise it includes the Weipu 12 pin connector in the package. The EVERLAST website did not have the connector shown in the items included photo or the descriptions. So, FYI to any other interested parties looking at this machine. It also came with a 110 pig tail, so it's a quick setup for me.