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Offline Davek0974

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Re: 1st pierce is longer...
« Reply #10 on: August 18, 2014, 10:46:28 AM »
This is not working for some reason!!

Just spent an hour recalibrating my pierce times to take into account the faster response of Mach without the DoSpin commands BUT when I put the first simple job on with only two 0.1s pierce delays, the first one works perfectly and the second one is ignored and the torch fires and starts moving immediately, ignoring the delay completely and piercing on the run.

Useless.

It is the same issue as before, only quicker - the first pierce is longer!.

Need help now please?????

Offline Davek0974

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Re: 1st pierce is longer...
« Reply #11 on: August 18, 2014, 10:47:20 AM »
This is not working for some reason!!

Just spent an hour recalibrating my pierce times to take into account the faster response of Mach without the DoSpin commands BUT when I put the first simple job on with only two 0.1s pierce delays, the first one works perfectly and the second one is ignored and the torch fires and starts moving immediately, ignoring the delay completely and piercing on the run.

Useless.

It is the same issue as before, only quicker - the first pierce is longer!.

Maybe the 0.1s delay is just silly and the consecutive pierces are behaving as they should BUT the first pierce is still way too long????

I could try upping the 0.1s to 0.4 or 0.5 maybe and try that but then the first one will still be long.

Need help now please?????
« Last Edit: August 18, 2014, 10:56:13 AM by Davek0974 »

Offline Davek0974

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Re: 1st pierce is longer...
« Reply #12 on: August 19, 2014, 02:32:39 AM »
MORE INFORMATION.....


Been thinking all night and just did a test,

this issue is related to the THC somehow, maybe the ArcOk signal?

With THC OFF, my system works ok, turn THC ON and it not only has a longer first pierce/shorter second one BUT also skips the torch-lift at the end of the first cut so it drags the torch along the plate triggering an E-stop.

This is all related to changing the DoSpin commands to ActivateSignal so what is going on??

Obviously i can replace the DoSpin commands but thats not fixing the issue.

Offline Davek0974

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Re: 1st pierce is longer...
« Reply #13 on: August 19, 2014, 03:41:10 AM »

Offline Davek0974

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Re: 1st pierce is longer...
« Reply #14 on: August 19, 2014, 08:15:06 AM »
Anyone know of a way that the Arc-Ok signal can freak Mach out?

Seems like its missing lines of gcode but dont know why, how can it stop the torch from lifting at the end of a cut?

Offline Davek0974

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Re: 1st pierce is longer...
« Reply #15 on: August 19, 2014, 10:21:17 AM »
THIS IS DRIVING ME INSANE NOW :)

I looked through the Proma leaflet, and it clearly states that NO output will be energised when only the pilot-arc is struck i.e. firing in air.

So i threw in some used consumables, switched to the diag page in Mach and fired the torch in air, sure enough I was getting an Arc-Ok signal, this is WRONG and possibly what is messing up Mach3.

So I noted the voltage displayed when the torch was firing in air (150v) and turned the HV setting in the Proma box down to 140v. This is higher than my highest cutting voltage BUT lower than the pilot voltage as I presume this is how Proma detects Arc-Ok.

But now when I try to run code, the arc will fire but as the torch pierces quickly on the 1.5mm test sheet, it then reverts to a pilot arc before Mach has time to drop the torch to cut height and start moving.

It's a no-win situation, I either have the long, unreliable pierce delays by using DoSpin() and setting the Proma back to instant arc-ok OR have fast on off with activatesignal() and a sensible arc-ok signal but not be able to cut :)

Anyone please got any ideas?


Yes I do know I can put it back how it was but long pierces on thin metals are bad for various reasons.

Offline Davek0974

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Re: 1st pierce is longer...
« Reply #16 on: August 20, 2014, 05:09:53 AM »
Don't worry, I'm ditching this THC and ordering an MP3000 from CandCNC.

Offline stirling

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Re: 1st pierce is longer...
« Reply #17 on: August 20, 2014, 05:24:58 AM »
This seems to be related...
http://www.machsupport.com/forum/index.php?topic=17435.5;wap2

Not just related - it seems to me to pretty much cover your issue.

I looked through the Proma leaflet, and it clearly states that NO output will be energised when only the pilot-arc is struck i.e. firing in air.

So i threw in some used consumables, switched to the diag page in Mach and fired the torch in air, sure enough I was getting an Arc-Ok signal, this is WRONG and possibly what is messing up Mach3.

As you say - this is incorrect behaviour of your THC. I can only suggest you take this up with Proma.

So I noted the voltage displayed when the torch was firing in air (150v) and turned the HV setting in the Proma box down to 140v. This is higher than my highest cutting voltage BUT lower than the pilot voltage as I presume this is how Proma detects Arc-Ok.

Ark-OK should be established by a THC when CURRENT is detected in the CUTTING arc as opposed to current in the pilot arc. i.e. when the pilot arc actually transfers to a cutting arc.

But now when I try to run code, the arc will fire but as the torch pierces quickly on the 1.5mm test sheet, it then reverts to a pilot arc before Mach has time to drop the torch to cut height and start moving.

This is to be expected. It is not so much the cause of your problems but a symptom of them. Once you have pierced the system MUST start cutting otherwise the arc will start to deviate to find the edge of the pierce hole. Eventually it will not be able to deviate far enough as it widens the hole and will therefore not be conductive. Current ceases and so the torch flips back to pilot. The hole is now too wide to allow transfer so the pilot will remain until timeout.

EDIT: you just posted at the same time - but I'd written it so I'll leave it for your interest.

Offline Davek0974

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Re: 1st pierce is longer...
« Reply #18 on: August 20, 2014, 05:39:40 AM »
Thanks Stirling, hopefully, using a more recognised and supported THC like the MP3000 will give me a lot less grief, I think it will.


Dave

Offline Davek0974

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Re: 1st pierce is longer...
« Reply #19 on: September 06, 2014, 08:21:24 AM »
Well, a new THC did not have any effect, the first pierce is still longer.

On a drill op it's the difference between a small peck with the torch or a complete pierce.

This is with an MP3000 from CandCNC.

Arc-ok does not come into it as there is no torch movement, pierce delay is set to 0
The torch does not drop from pierce height, it's simply M3 then M5.
« Last Edit: September 06, 2014, 08:24:30 AM by Davek0974 »