Zero CNC Experience DIY Plasma table THC guidance needed

[shaolincrane]

I am using a Fangling portable CNC plasma converted to a table. Has a F2100B Controller and F1621 THC. I reused the nema 23 motors that were inside the unit and designed my own drive and gantry. I repurposed a grainger machine cabinet to act as a water table and be able to break down if needed.

So far making shapes with a marker works outstanding but I am having issues with the THC getting voltage signal. The English in the manual isn't the best and I'm trying to discern if it needs 50:1-100:1 or if the internal board uses raw voltage and converts, if so it may explain my problem.

I am using a Cutmaster 52 with the CNC automation board and SL100V automation machine torch.

My issue is when cutting, the THC probes the height, starts the arc to pierce but since the THC doesn't detect the voltage the cut fails and sets an arc break alarm.

I opened the THC and found a switch for 100:1 or 50:1 and I'm thinking it may not be getting enough voltage to sense since the CNC board is already reducing to 50:1 but cannot be certain, I have near zero experience with CNC. If that is the case it was a waste of a good chunk of money to buy the CNC board.

Any help would be outstanding.

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[acourtjester]

Welcome aboard Shaolincrane, Please no high kicks.
From you posting of the manual pages it looks like it is to use raw voltage connection from the Plasma unit. It also has a Ohmic sensor connection with it.
Now to give you some info you G-code needs to separate the pierce action from the THC, there is a time delay to keep them separate.
The first action is the find the metal surface with Ohmic sensing then the pierce action, after a short time the torch moves to the cutting action. Then after a short time the THC comes into play, the delay is to allow the arc voltage to stabilize. this delay is about 1 to 1.5 seconds, if to soon the THC will react and the torch is not controller as it should. Also the THC should not be reacting to quickly as the torch will bob up and down to much. This take a little fine tuning for your setup to have all things working at the correct time.
There needs to be a good connection to the metal being cut and the plasma work lead (connection) and the controller so there is a path for the Ohmic sensor to work. I am not sure the Cutmaster 52 has the same type of shield connection as the Hypertherm (shown in the manual pages). Maybe another member can clear this up as I have never used a Cutmaster plasma unit.

[shaolincrane]

Welcome aboard Shaolincrane, Please no high kicks.
From you posting of the manual pages it looks like it is to use raw voltage connection from the Plasma unit. It also has a Ohmic sensor connection with it.
Now to give you some info you G-code needs to separate the pierce action from the THC, there is a time delay to keep them separate.
The first action is the find the metal surface with Ohmic sensing then the pierce action, after a short time the torch moves to the cutting action. Then after a short time the THC comes into play, the delay is to allow the arc voltage to stabilize. this delay is about 1 to 1.5 seconds, if to soon the THC will react and the torch is not controller as it should. Also the THC should not be reacting to quickly as the torch will bob up and down to much. This take a little fine tuning for your setup to have all things working at the correct time.
There needs to be a good connection to the metal being cut and the plasma work lead (connection) and the controller so there is a path for the Ohmic sensor to work. I am not sure the Cutmaster 52 has the same type of shield connection as the Hypertherm (shown in the manual pages). Maybe another member can clear this up as I have never used a Cutmaster plasma unit.

Thank you, it is currently set for a limit switch but does have the ohmic function as well. It can be set for Ohmic, limit or proximity switches. I can run an IHS test and it all works well, just no arc voltage. The manual eludes to saying voltage will not sense if the ohmic is not set up but I don't believe that to be the case with the options available, if it is then it's a simple fix.

If it's true it only takes raw voltage then again another simple fix but the manual days it will sense from 0v-660v so I thought I should be seeing something.

The G code should be fine, I see the steps you are talking about on screen, these are pre installed shapes that come with the machine and without cutting the draw just fine.

[acourtjester]

Ok if use either floating head switch or Ohmic sensing they need to be part of the G-code. You can use either both or none, they need to be set in the post processor so the software (G-code) will know what to look form. If you use an Ohmic sensor that only looks at the Z command in the G-code. A G31 is for the Ohmic sensor and G28 is the Floating head switch. If using a Floating head switch it can be hooked in as a Z home. I set all the homing and limit switches in series, the floating head switch can be added with them or separate. It is just how the controller is wired and the Ohmic sensor is set as a probe input by itself, that is why it uses a G 31 command. It could be a different G code number the software should show which it wants for the Probe, I have seen also a G38 for ohmic too. Limit or proximity switches act the same just wired differently (proximity needs a voltage to power them). If you string the home and limit in series they need to be in a normally closed configuration, any open with trip the circuit.
If your setup uses a 50:1 then the output from the plasma will be much lower like less then 4 volts. Most Plasma unit will state you can select a voltage divider output going to a external connection. For raw voltage output you may need to make connections yourself to the work lead and the torch wiring.

[shaolincrane]

Ok if use either floating head switch or Ohmic sensing they need to be part of the G-code. You can use either both or none, they need to be set in the post processor so the software (G-code) will know what to look form. If you use an Ohmic sensor that only looks at the Z command in the G-code. A G31 is for the Ohmic sensor and G28 is the Floating head switch. If using a Floating head switch it can be hooked in as a Z home. I set all the homing and limit switches in series, the floating head switch can be added with them or separate. It is just how the controller is wired and the Ohmic sensor is set as a probe input by itself, that is why it uses a G 31 command. It could be a different G code number the software should show which it wants for the Probe, I have seen also a G38 for ohmic too. Limit or proximity switches act the same just wired differently (proximity needs a voltage to power them). If you string the home and limit in series they need to be in a normally closed configuration, any open with trip the circuit.
If your setup uses a 50:1 then the output from the plasma will be much lower like less then 4 volts. Most Plasma unit will state you can select a voltage divider output going to a external connection. For raw voltage output you may need to make connections yourself to the work lead and the torch wiring.

https://a.co/d/j9yL1iZ

This is the machine and so far I'm using the base programming. If I'm understanding the Chinglish of the manual, the programming has gcode for each option. I only poked around in there once but I think I did see a G31 and G38. Testing the ohmic function works as well so I'm sure all of the Gcode options are there. Eastwood uses the same controller and THC in their table and push Fusion 360 for the post processor. One thing that the Eastwood table does not have is home functions for the X and Y but while inwas going through the manual and controller it is available as an option and once I get the table cutting on its own I have switches to wire in, which I'm sure will need a gcode addition.

When I test the divided arc voltage during pierce I get 6-7 volts. The TD CNC board has 16:1, 30:1 and 50:1. Could it be possible to change the jumper to 16:1 to see if the THC will register some voltage? I purchased this machine as an Amazon return for a song, so there's a possibility it was returned because something didn't function, if I can eliminate the THC as being potentially faulty then I have no problem using raw arc voltage.

[acourtjester]

Ok that helps with the THC section, the plasma arc voltage is about 80 to 120 so the range you say of 6 to 7 volts puts you using the 16:1 settings. This should put the THC operations where they should be and not using the raw voltage but a divided voltage which is safer.
Did they give you a post processor to use when creating a G-code?
When planning an operation the part drawing is processed by a CAM program using a Post Processor that is setup for the electronics and G-code commands that work with your machine. It seems your software is a package which combines the CAD and CAM and the operational functions all in one.
If this the correct you don't need to worry about a post processor as it is just one of the steps in the process.
Looking at your images and the web page you have combined 2 machines to have a CNC table for cutting.
As long as things are in working order with help you should get things sorted out and have a functioning table to use. Not sure if there are any members that have a similar unit to the one in the web page that can address the actual functions and operation. Much of it is basic and can be ironed out, which you have already done.

[shaolincrane]

Ok that helps with the THC section, the plasma arc voltage is about 80 to 120 so the range you say of 6 to 7 volts puts you using the 16:1 settings. This should put the THC operations where they should be and not using the raw voltage but a divided voltage which is safer.
Did they give you a post processor to use when creating a G-code?
When planning an operation the part drawing is processed by a CAM program using a Post Processor that is setup for the electronics and G-code commands that work with your machine. It seems your software is a package which combines the CAD and CAM and the operational functions all in one.
If this the correct you don't need to worry about a post processor as it is just one of the steps in the process.
Looking at your images and the web page you have combined 2 machines to have a CNC table for cutting.
As long as things are in working order with help you should get things sorted out and have a functioning table to use. Not sure if there are any members that have a similar unit to the one in the web page that can address the actual functions and operation. Much of it is basic and can be ironed out, which you have already done.

I have it set for 50:1 according to the TD instructions. I got a hold of Fangling and they confirmed that the machine only works with raw voltage and the switch that allows you to switch between 100:1 and 50:1 doesn't do anything, it will only operate at 100:1.

The machine came with a Starcam program that for the life of me won't work, says the USB is corrupt. Which is fine because I have been using Fusion 360 anyway. Eastwood has a postprocessor they use for Fusion 360 that uses the exact same setup. I'd prefer to keep using Fusion 360, I couldn't really do anything well on Starcam or Sheetcam. I was able to design all the parts for the table fairly easily even with my limited experience. I had a local guy cut the parts and he said they worked fine.

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[acourtjester]

Well that is a big plus, you have found most of what you need, and questions answered. Do research on how to wire up the TD for raw voltage use and you should be good to go, just be careful with Raw voltage. For cutting thin metal it is good to have the Ohmic sensor for metal surface detection.
Many are using Fusion360 so if you have questions about that you can get them. With many things if you like using something you get better at it, so go for it. Maybe later after you get comfortable you can look at SheetCam again as it may have functions you want, but not necessary.
There are many great projects posted here you can download them, may help you get more experience.
Have fun

[shaolincrane]

Well that is a big plus, you have found most of what you need, and questions answered. Do research on how to wire up the TD for raw voltage use and you should be good to go, just be careful with Raw voltage. For cutting thin metal it is good to have the Ohmic sensor for metal surface detection.
Many are using Fusion360 so if you have questions about that you can get them. With many things if you like using something you get better at it, so go for it. Maybe later after you get comfortable you can look at SheetCam again as it may have functions you want, but not necessary.
There are many great projects posted here you can download them, may help you get more experience.
Have fun

The ohmic function seems nice, I'm trying to see if the TD Machine torch has a lead for it like the Hypertherm does, I van see inside the ATC it has several extra leads but have not been able to find a wiring diagram for it.

[acourtjester]

There is something you should check you said that TD has divider switch settings of 100:1 and 50:1. And Fangling runs on Raw voltage, that means no divided voltage switch setting but from the torch lead and the work lead connections.

[shaolincrane]

There is something you should check you said that TD has divider switch settings of 100:1 and 50:1. And Fangling runs on Raw voltage, that means no divided voltage switch setting but from the torch lead and the work lead connections.

That's for the Fangling, not TD. The CNC board for TD is 16:1, 30:1 and 50:1
That's where the conflicting information is. In one manual for the fangling it says I can choose, but after speaking with the engineer, the switch doesn't actually do anything and can't be changed and can only operate off raw voltage. Had I know this I wouldn't have needed the CNC interface kit for the TD, oh well.

I spoke with TD for the location of the raw voltage terminals and the ohmic leads in the torch and will get to it sometime tomorrow.

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[acourtjester]

Sounds good, put the TD parts on Plasma spider maybe someone will but them.

[djreiswig]

Why would they put a switch on the board that doesn't do anything?

[shaolincrane]

Why would they put a switch on the board that doesn't do anything?

They offer a range of products in the F162X line, that side of the board says F1620, my controller is a F1621. If I were a betting man, they probably use that board as the base hardware and change the secondary board for the different models and it likely doesn't support the function. I'm giving them the benefit of the doubt because it's pretty common in my experience with Chinese goods. Could also be an older model did use the switch and they just keep using the same tooling to cut cost and the switch no longer functions. Who knows.

[shaolincrane]

This week was a complete cluster so this was a very satisfying thing when it finally happened. At least TD makes it easy to get raw voltage off the main board.

Now I just need to brush up on cutting speeds and other important settings but I'm satisfied with how smooth the table works. Next thing will be cleaning up the wiring mess and final loom of the wires.

[acourtjester]

Congrates, make you feel good when it cuts, maybe a little fine tuning and you can start cutting things for your projects.

[adbuch]

This week was a complete cluster so this was a very satisfying thing when it finally happened. At least TD makes it easy to get raw voltage off the main board.

Now I just need to brush up on cutting speeds and other important settings but I'm satisfied with how smooth the table works. Next thing will be cleaning up the wiring mess and final loom of the wires.

Your are making some great progress! We'll look forward to seeing some of you projects once you get going on them.
David

[shaolincrane]

This week was a complete cluster so this was a very satisfying thing when it finally happened. At least TD makes it easy to get raw voltage off the main board.

Now I just need to brush up on cutting speeds and other important settings but I'm satisfied with how smooth the table works. Next thing will be cleaning up the wiring mess and final loom of the wires.

Your are making some great progress! We'll look forward to seeing some of you projects once you get going on them.
David

Thank you, I appreciate it.

Does anyone have any input about using this type of shielding?
Electriduct 1/2" Tinned Copper Metal Braid Sleeving Flexible EMI RFI Shielding Wire Mesh (0.32" Diameter) - 10 Feet https://a.co/d/6mb0o3Y

I used shielded wiring on the motors but the signal wires from the plasma are not shielded. It isn't causing problems but since I needs to clean up and tidy the wires it wouldn't hurt to use some shielding if it's necessary. If not nylon braiding it is.

[adbuch]

I don't think it is necessary. My torch control cable (arc voltage plus trigger activate) is not shielded and it works fine. I think the nylon braided would be fine to help to clean it up and bundle the wires together.
David

[shaolincrane]

Cool, that makes things easy. I mean the plasma will be inside the cabinet but just wanted to cover my bases.

After that I just need to find a R300 drag chain for the torch cable which is more difficult than I expected. TD recommended a 12" bend radius and R200 seems the be the most common via Aliexpress. Most other places that I have found them sell them for something crazy, like $27 a link.

[acourtjester]

I do not use a drag chain for my Plasma cable I have a cable boom which brings my cable in from above. Much simpler to route the cable since I also use my table for router work I just remove the torch and cable and run the router power cable in it's place. I also run the router dust collection hose with the router power on the boom. I put a swivel on the end for the larger table in the center side of the table which helps the boom follow the cable.

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[shaolincrane]

I do not use a drag chain for my Plasma cable I have a cable boom which brings my cable in from above. Much simpler to route the cable since I also use my table for router work I just remove the torch and cable and run the router power cable in it's place. I also run the router dust collection hose with the router power on the boom. I put a swivel on the end for the larger table in the center side of the table which helps the boom follow the cable.
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2 tables 4x4 and new 4x8.JPG

I definitely don't want a boom, I basically already have it set up as a boom and it's already annoying me. Luckily I found a seller on Aliexpress that is making a custom one. 2 meters shipped to CA for $97. I will however like to add a laser soon for engraving work.

[adbuch]

Tom - that's a nice looking setup! I have a "boom" on my Plasmacam table as well and it works fine for me. My cnc wood routers do have drag chains and they work well also.

David

[shaolincrane]

So I loomed everything fairly well and went to load some of the files I made and for the life of me cannot get it to recognize the USB at all. I have tried nearly every configuration of formatting in Fat32 like it says and nothing works.

Any ideas?

[adbuch]

So I loomed everything fairly well and went to load some of the files I made and for the life of me cannot get it to recognize the USB at all. I have tried nearly every configuration of formatting in Fat32 like it says and nothing works.

Any ideas?

Please refresh my memory as to exactly what you are attempting to do with your usb connection.
Thanks,
David