Plasma Firing sequence problems

[CPR]

Hi, Im new to this forum.

Im Having issues

I run a Panther engineering table with Starfire controller and HYDAC THC. the Plasma source is a 100SD Thermacut Extra fire.

i use fastcam 7 software

issue is when the cut file starts, the torch touches down comes up to pierce height it sometimes starts to move before torch pierces missing some of the cut. It generally starts the first pierces fine then progressively gets worse. more so when ive nested items.
Not sure if its a controller problem or fast cam problem.
i have good earthing setup.
i have grounded the table etc, changed consumables etc but still does it.

When i start stop the plasma in manual K4 Start K8 Stop it starts fine

any one had any similar issues.

Cheers Chris

[acourtjester]

If sounds like you are not checking for the arc OK or what ever signal that checks the plasma if actually on before it moves. This also triggers the start of the pierce delay to insure the metal has been pierced before moving. Is this a new system or a problem that has just started to happen. You may be using the wrong post processor, one that may not look for the arc OK signal.

[adbuch]

I agree with Tom on this one. Make sure that you are monitoring your "arc OK" signal so that your torch doesn't start moving until it verifies arc, and then waits for the specified pierce delay time.

David

[weldguy]

Your controller may not even accept an arc OK signal and may work strictly off of timing the pierce delay and a purge delay.

Do you know if you are bringing and ARC OK signal back to your controller from the plasma cutter?

[CPR]

Hi thanks for the replys
The machine is two years old and I feel as though it has had this problem from new
Its the first cnc plasma cutting system that I have owned so has been a big learning curve
It is an inconsistent problem that seems to be more apparent now
Maybe because I have become more aware of the finer details of cutting
It runs fine for some cuts then will have this problem constantly
Finding it hard to understand the manual as it’s Chinese converted to English manual and a bit misleading in translation
I don’t know if it has an ark ok signal or relying on time
I will take some pictures of my craft settings and post them
Its a Chinese mmc starfire controller
It has done alot of work faultlessly,eg cut 500 roof truss cleats from 8 mm plate without missing a beat,then will constantly doing this on another day
Very frustrating
Have tried to get answers from supplier but they are very good with the help
I have another thermacut plasma machine and have tried it on the machine and had the same inconsistent problem
Will try and post some pics tomorrow
What are you people using as controllers
I think I need to try and source a better quality controller with good backing and someone that can help with teaching me how to use it
Cheers
Chris

[CPR]

Was supposed to say supplier isn’t very good with help as there is a language barrier there

[acourtjester]

There are a few thing you can look at. First Google has a language translate function so you may be able to use that for better communications to explain your problems to them. With it doing a good job sometime and not so good other times, it may be to tool setup (electronic configuration ).
Does it cut better for one thickness then others?? Thinner metal cuts move faster, these things are where the tool setting would be different. If you send a snippet of the G-code from the cut routine that you are having a problem with. Just the section at the start of the cut to a few line after the torch fires (M5). Replacing the controller may be a little harder depending on the electronics they use. Like if they used a single purpose computer, not like many those that use a computer with Windows or Linux as its operating system. And how well you work with electronics and schematics. I would not think the Thermacut is your problem.

[weldguy]

Pictures would be great.

How many wires are used to connect the plasma cutter to the controller?

[4130metalworks]

I had that controller on one of my machines, it was swapped straight away with a masso g3 touch. If you are going that way you might have to swap the z axis too as they use 12 volt dc motors not nema so isn’t compatible with any other controller

If you’re on Facebook there is a group called Chinese cnc plasma table owners or similar to that, they would be your best bet for help
The thermacut has an arc ok output, its a simple switch. The in and out wires are on the back in that round plug

[adbuch]

I had that controller on one of my machines, it was swapped straight away with a masso g3 touch. If you are going that way you might have to swap the z axis too as they use 12 volt dc motors not nema so isn’t compatible with any other controller

If you’re on Facebook there is a group called Chinese cnc plasma table owners or similar to that, they would be your best bet for help
The thermacut has an arc ok output, its a simple switch. The in and out wires are on the back in that round plug

4130metalworks - that is great information to share and should be very helpful to the OP.
Thanks,
David

[tcaudle]

Its a (very) budget level controller and THC. The Chinese are good at mechanics , less so on software and CNC controllers. The pots from other members are spot on about "Arc OK" ( also called "Transfer" or "OK to MOve"/ You plasma machine may not have that signal and even if it does there may not be an input on the THC that will feedback tot he motion control to HOLD motion.

Sometimes other factors should be considered on a purchase besides just price.

Because the Starfire is not a PC based CNC controller the THC is typically a semi-stand alone type that does its own Z moves outside the other axis motion. That makes the touch off and pierce moves somewhat disconnected .

[CPR]

HI People, Sorry for the delay in replying.
Thanks 4130metalworks and tcaulde for the advice.
Attached is some files.
Not very good with electronics sorry
will check out the face book group.

cheers

Chris

[weldguy]

From your second pic it appears as though your machine has only a 4 wire connection to the plasma and is not using a ARC OK signal so you will be relying on timing.

If the torch is beginning to move before it has pierced the material you want to increase the pierce delay time. This is not a set it and forget it type of setting, thicker materials take longer to pierce and will require a longer pierce delay. Document what works for each thickness of material you cut for future reference.

With many plasma cutters the initial pierce will need to delay longer to allow the air to reach the torch before arc initiates, after the first cut many have a post flow where air will continue to flow out of the torch for a set amount of time, during this time often the arc will initiate immediately since air is already flowing. Some controllers will have a setting for this post flow time that will also allow you to get the timing correct for the initial and the following pierces.

You may need to play with it a bit to get it dialed in but def curious to hear what you find out.