Advanced Search

Hi everyone, and hi @tommylight ! I'm here for an update after a while using the table.
I'm very glad I built this machine, it saves me a ton of time. It already paid for itself as I had an order of 50m of guardrail with a lot of sheet metal. It would have drove me crazy cutting it with the grinder.

I did some changes though. Upgraded the X axis motor from a nema 17 (65Ncm) to a nema 23 (1.26Nm) as it was sometimes missing steps due to a lack of torque. I also removed all the cable to the limit switches (exept the float ofc) as there where not really necessary and added a lot of cable which could get stuck during movement. I can easily put them back if needed though.

I'm really impressed on how clean it cuts thin sheet metal when you got the setting right, even with my cheap chinese plasma cutter. I have almost no post grinding to do and the slag just go away easily with a scrapper. I feel, again, I'm saving so much time and health using less the grinder.

I have a bit of time ahead of me so I started to set up the THC (I wasn't using it until today). Of course i doesnt work and I have no idea why.

First I'm not sure what I should enter when asked for the voltage divider. I'm using a THCAD-2 with two 1MO resistor on both + and - cable. I've entered THCAD-2 with W1 UP when asked during the configuration. By default there is a 20 ratio voltage divider. I would say I have no voltage divider and should enter 1 but I'm not so sure...

Anyway, I'm pretty sure it isn't what makes it not work. When cutting, even though I have enabled the THC (both in QTplasmaC and in sheetcam) the "active" indicator on QTplasmaC never turn on. I'm not sure where to start to know what's wrong (the physical led on the THCAD-2 board is turned on though).

I'd like to again thank the linuxCNC community for helping me to build this plasma cutter. It tremendously help my small buisness to be profitable.

Well, I guess I’m stuck and didn’t explain my issue.
I set up a config in axis. X and y axis move appropriately when jogged, and the dro displays accordingly.
My 4 limit/home switches trigger in halshow. The limits will trigger machine power button.
My 2 inputs trigger digital inputs in halshow.
My 2 outputs get triggered when commanded in halshow.
And I don’t know where to go from here. I’m stuck. If I bought a new lifter, I’d be stuck in the same spot.

I obviously need to link the I/o’s to functions/buttons/gcode, but I don’t know how.
Im reading the manual and trying sample axis configurations, but I just can’t get anywhere.
Like input 1 is the breakaway. But I can’t figure out how to tell that to linuxcnc. 
I thought maybe I can just copy the limit switches, but I don’t even see how they trigger the machine off button in any of the hal or ini files.
And if I can’t figure out the breakaway, I don’t have much hope for cycle start or thc hold.

Is it rude to ask for a plasma specific axis configuration?

I appreciate the input, I just wish knew enough to ask the right questions.

Rodc, I assumed you suggested the lifter for functionality, but maybe you’re actually telling me to use a lifter that integrates with qtplasmac. I did consider using Linuxcnc to control the z motor and read arc volts with a mesa thcad instead of the standalone hypertherm phc control, but I thought that just sounded like more work, more money, and more potential pit falls. But in retrospect maybe I should’ve done that just to make it easy to use qtplasmac. And a mesa card that works with pncconf instead of mesact 

Von 7i96S.
Kein externes strom, das macht probleme mit potential und interference.
Das sind nur 4 drahte fur die THCAD von Mesa 7i96S, dan 2 fur torch on und 2 mehr wen die ARCOK von plasma nutzt.
Ein gute CAT5 oder CAT6 LAN cable mit schirm (shielded) ist OK.

I have a plasma with 6 steppers as well

It's working great with qtplasmac, 7i96s, 2thcads one for the one for ohmic, parallel port breakout for the other steppers board running on a ryzen 1600

Couldn't recommend it enough. Use 2.9.2 if you want the rotary to work 2.10 wasn't working with the sheetcam post as of a few months ago.

I managed to install Linuxcnc on an old pc.

It seems for what I want or need.
a 7I95T + THCAD2 would be the way to go.

The thing is my machine is Router/plasma combo with rotary and laser and on top of that a probe will need to be installed.
In the future I will separate the tables.

Thanks to all!

 

Hello.
I am running or trying to run an Avid cnc router and plasma combo with rotary.
After 3 years of messing with this and replacing 3 pc's and multiple install I can confidently say that Mach4 is garbage. Machine is solid.
I am looking into replacing the electronics for either Uccnc or Linuxcnc. In the future build a plasma only table running either Linuxcnc or Myplasm cnc because from what I see both of these have a better way to recover a failed cut than Uccnc and Mach4.

Now I have 3 available pc's i5 4th gen 8gb hdd, i7 4th gen 20gb hdd and i5 11th gen 16gb ssd. are all these 3 a good choice for Linuxcnc?

Is Debian 12 good for Linuxcnc? I am a total noob on Linux ...I am using right now an old toshiba laptop that could not run windows and running Linuxmint smoothly but more than a month struggling to boot up from hd :/ still booting from usb.

I was advised on a Mesa 7196s+THCAD2  but I need to drive 6 motors...1 for the rotary...I was so fed up with Mach4 that I did not even bothered to use the rotary.
What to do in this case?
going from Mesa to the motor drivers do I need a breakoutboard?
Which values would I need from Mach4 to use in Linuxcnc?
Is Linuxcnc is good with probing?

My plan is to install Debian on one of my old desktop and install Linuxcnc uspace to test the simulation.
One thing I do not understand about Linux terminal....If I install from the terminal which version does it install?

Let me know If I am in the right direction here....I am trying to make parts not trying to make the machine run.

Thank you!
 

That board looks sweet!

If you have analog ports that could be broken out I would buy one. Have a few projects in mind that need a analog port (thinking a height control for a CNC CO2 laser that follows the warped wood..yes a thcad would work but a few more projects need 10+ analog input). 4-20ma is preferred over 0-10v due to noise issues.


I like the plug in design for stepper motors as can probably find cables so we don't have to wire them by hand.

Personally prefer Ethernet cables for everything as they are much easier/faster to crimp by hand than those white connectors and I can wire directly to a machine 20 foot from my control panel. Wire and connectors are cheap and abundant

What makes projects like this succeed and become interesting is good setup instructions and documentation. Bonus points if you can make a pnf config style config generator. Time is much more expensive than the boards themselves, I'll pick a $250 mesa board over an unknown one with no documentation because it's going to save me $1k+ in time.

Hope you keep developing it. Looks awesome!

Yes, you can extend the range of any THCAD by adding an external resistor
The calculation of the value required is shown in the THCAD manual, for a THCAD-10
it would be:

REXT = (VFS - 10V)/100 uA  Where REXT is the external resistor added to VIN-
and VFS is the desired  full scale voltage.

This is for example 2.4M for 250V full scale

will the THCAD10 also work? I think I have a guy that has one I can buy for cheap, I ended up ordering a plamsa cutter that has a 1:1 voltage ratio, so can I use the THCAD10 with an external high voltage resistor?