Machsupport Forum

G-Code, CAD, and CAM => G-Code, CAD, and CAM discussions => Topic started by: Bob M on August 05, 2020, 01:28:58 PM

Title: M3 and M5 for plasma on off execute early
Post by: Bob M on August 05, 2020, 01:28:58 PM

Hi all,
         I have mach3 with a NVEM motion control on a home built plasma table.
motion is good and calibrated.
single stepping works but when I run G code the M3  plasma start  command executes before the previous move finishes, stopping before end of cut.
If I  then rapid to another cut the plasma restarts during the rapid.
stepping the code runs as expected.
I get the same problem with any G code source it seems.
The start and stop are shown on the toolpath in the incorrect places also.
I get the same result with moving the torch signal to he flood output and editing the Gcode M3 M5 to M8 and M9
It is not plasma noise I get the same result with a lamp on the plasma drive.

Has anyone experienced this or got a solution please.

Regards

Bob

Title: Re: M3 and M5 for plasma on off execute early
Post by: Tweakie.CNC on August 06, 2020, 01:05:17 AM

Hi Bob,

Unfortunately Novusun products are not supported. This thread refers; https://www.machsupport.com/forum/index.php?topic=24331.0

Tweakie.

Title: Re: M3 and M5 for plasma on off execute early
Post by: Bob M on August 06, 2020, 06:00:15 AM

Hi Tweakie,
                  Thanks for the prompt  reply.

Can you recommend a better controller, this is my first build, everything else is good.

Regards

Bob

Title: Re: M3 and M5 for plasma on off execute early
Post by: Tweakie.CNC on August 06, 2020, 06:24:44 AM

Hi Bob,

Any of the US or EU manufactured controllers are good.
The Warp9 ESS is a good all-rounder and has plasma capability. Check out their website and forum for more details.
 https://warp9td.com/

Tweakie.

Title: Re: M3 and M5 for plasma on off execute early
Post by: Bob M on August 06, 2020, 06:47:22 PM

Thanks Tweakie,
                         looks like I backed a bad deal.
I  am a retired university engineer with a technical background initially.
so I built the table which works as expected.
no plasma start problems, I hope I knew how to deal with that.
I am a bit worried if I dump the existing setup I will still see the switching problem where the M3 turns the plasma on before the last move rapid ends and off before the cut move ends.
If I buy the controller you suggest and mach4 will this resolve the timing problems.
If I may ask  question the Mach3 core appears to run through an interpreter why is it not compiled.

Thanks again for your reply.

I am away for over a week so cannot respond until then.

Regards

Bob

Title: Re: M3 and M5 for plasma on off execute early
Post by: Tweakie.CNC on August 07, 2020, 01:07:53 AM

Quote

If I buy the controller you suggest and mach4 will this resolve the timing problems.

Unfortunately I do not have a plasma set-up to test so cannot answer your question with any certainty. Perhaps reading and asking questions on the Warp9 forum would be the way forward.

Tweakie.

Title: Re: M3 and M5 for plasma on off execute early
Post by: Graham Waterworth on August 13, 2020, 08:50:52 PM

You could try changing to exact stop mode before the torch start/stop commands, thus forcing the last move to end before the M command.  Just make sure the M is on a line of its own.

Title: Re: M3 and M5 for plasma on off execute early
Post by: Bob M on August 17, 2020, 09:37:09 AM

Thanks Graham,
                       For taking time to reply.
That is exactly what I need, the previous move instruction to complete before the m3 or m5 executes.
 I dont know what excact stop mode is or how to implement it.
I will look it up and will give that a try.

Regards

Bob

Title: Re: M3 and M5 for plasma on off execute early
Post by: Graham Waterworth on August 17, 2020, 09:51:51 AM

Check out G61 exact stop mode, finish last move before next command, no blending and G64 constant velocity mode normal profiling mode with blending of moves.

Title: Re: M3 and M5 for plasma on off execute early
Post by: Bob M on August 17, 2020, 04:13:54 PM

Thanks Graham,
                        I will do. To save loosing my investment so far I am considering either an external solution with a microcontroller  looking at the stepper pulses and waiting for the end of current move before starting then holding the arc on until the cutting  move ends.
I prefer your programming solution if I can make it work.
other option is to start again with perhaps 3D printer software and controller, which I have experience of.

Regards

Bob