Works! Nice work thanks for the new video that I was wondering about how to connect it to my table but I see it's just has its own actuator. Cool project thanks for sharing.

 

Can anyone provide a schematic for the divider needed ?

Or is there a good prebuilt unit out there for sale ?

 

You could read the step and dir signals from your board with the arduino,recalculate them in the microcontroller and send them to the stepper driver. This way the arduino is the only instance controlling the z axis and you won‘t need two z axes. This is what the proma compact thc does.

 

Built the THC and it works however occasionally when my plasma misfires it causes a voltage spike which has cooked two UNOs so far.
Any help,sketches or direction is greatly appreciated cause Im running out of UNOs

 

Opto isolated circuit design is your friend...
Build your own..

 

Anyone ?

 

I get how an optocoupler can protect but was under the impression they are ON or OFF and could not show the variable voltage needed to make this device work since there is a range of voltage being read not ON OFF ?

 

OK im searching thank yo

 

So the divider is done with Zener protection and works great however now I realize that after a cut and the torch extinguishes and the torch lifts, Does anyone know how to keep the torch down for the next cut (ie a parts with multiple profiles)

 

Hi,

i have 2 questions :

my plasma gys cut 45 ct give maximum 20Vdc in 20:1 so if I put 50:1 the analog input could be more than 5v (6,5 v) so is it ok ?

my plasma give me a contact which means that the arc is ok. Do you think Is interesting to use it ?

thank you

 

You cannot exceed 5 vdc or the board will cook

 

Hello,

i try to make my thc and i have problem with Settings views. I have to click more than 10 on button to change val (exemple min or max travel).

Next button and Plasma voltage are correctly refresh.

After search, i saw that the arduino don't receive correctly trigger.

What can is it ?

 

anyone have diagram to divider circuit?

 

Hello
Can you have both openbuilders Blackbox controller and THC controllers connected in parallel to the z engine or how do you do the most suitable.
Bengt

 

Hey I’m in the process of building this. I know you have not incorporated it into Mach 3. I was hoping maybe you could help me to code a couple inputs and outputs to your code.
First would like to use 2 inputs to arduino as up and down signals.
Next would be arc relay. Input and output. Input would come from Mach 3 and output would activate the relay and start the arc. This way Mach 3 could do a probe for material and set initial height from the probe. Actually maybe don’t need the relay to go through the arduino unless the arduino was set to probe for a height.(edit: I think I was thinking arc ok to start thc control mode. Not to start the relay.)
Anyways if the Mach 3 could send up/down signals to the arduino and do initial height settings and then be cut off from control after the arc ok signal is received then the thc could control z axis while cutting. I have found out how to have Mach 3 do what I’m hoping but not if I’m able to make the arduino do what I was thinking. anyways any help with a possible way of doing this will be greatly appreciated. Once I have all my parts and get the thc working then I will try to intergrate the up/down options into the arduino and Mach 3.

 

Had the same issues as you so changed to an UNO and your files and it works perfect, thank you. One thing i did notice though is that there is no other screens than the main and plasma screen, no next and back button, was this intentional?

 

One thing I have not completely wrapped my head around with the THC solution. Since it does not talk to the main plasma controller... When you start a cut, do you place the torch at a sufficient height to get things started, and after the torch pierces and starts cutting the THC controller will then maintain the height per the setting in the THC controller? I am assuming that you can't have the torch at a random high setting and it will adjust down when the cutting starts.

 

All the videos are private now. I watched them last week and bought everything needed. The videos were great, and to be honest, I think I’m going to need them. Thank you!

 

Do you have a link or can you tell me how I can watch the video? I'm getting ready to start on my first CNC plasma project and would really like to use this THC setup, but very new to all of this. Thanks in advance!!

 

Hey Retsaj! I am extremely interested in your build. Could you let me know how I can obtain permission to view your YouTube videos? I greatly appreciate it and the work you put into this project!

 

Is there a link to your design somewhere?

 

Wonderful build!

I'm in the process of building one of these, following your build instructions. I have a question about the initial height setting. I see how it moves the current position up and down as I adjust the pot (simulating the plasma cutter) but how is the initial pierce height set?

I was thinking of modifying the THC to do the following:
The CNC controller moves the torch to the XY position where the cut should start. It would then send a signal to turn the torch on. (This would now go to an input on the Arduino.) The Arduino would lower the torch until it touches (or better a sensor touches) then it moves it up to a set pierce height. Once in position, the Arduino fires the torch, and after a set delay sends a signal back to the controller to un-pause the G-Code. Once the cut is finished, the controller stops sending the torch "on" signal, the Arduino pulls the torch up to a preset rapid move height, ready to be moved to the next XY position to pierce again.

I saw on one of your videos that you have a height sensor attached. How are you incorporating it since I understood you to say that only your THC is in control of your Z stepper motor.

Has anyone tried this with the Hale Design?

 

I'm new to the Arduino stuff and even most electronics, but I am a tinkerer and I just built a CNC plasma that has touch off capabilities. With good flat plate or a drag tip and my floating head, it cuts great. But the drag tip isn't perfect. Ran across the videos for this THC a week ago and had another idea. I tied it into my existing GRBL controller using a relay module. Basically the GRBL board has control over all functions until the torch fires. The signal that closes the relay to fire the torch also enables the relay module to give the THC unit control over the Z motor after touch off. When torch stops firing, Z control reverts back to the GRBL board. Testing with a POT, the system works. Need to get my plasma cutter set up with a voltage divider and see what happens there, but it should work just fine.

Had a thought while driving today. I am using an Arduino Mega 2560, and saw the breakout board shield for the mega. Now I am wondering if the GRBL and the THC sketches can be combined into one and function with less components and less points of failure. I figure the worst that happens is I let the magic smoke out of a Mega. Think I'll try the cheaper Elegoo version. I got one of them working for my THC. Had to change the values that ran up to 800 and keep them under 500, but it worked. If I get the cheap one going, a good one should handle it just fine.

 

So how did you isolate the current from the plasma cutter from your muicrocontroller input pins?

 

That is overly complicated and completly unneccessary. You can accomplish the same in gcode with G38.2 command.