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Author Topic: Physical buttons for plasma  (Read 87801 times)

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Offline Hood

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Re: Physical buttons for plasma
« Reply #410 on: November 22, 2016, 03:47:26 AM »
I tried with different pressures but I also used the flow meter supplied with the torch to make sure there was enough at the torch.
Re: Physical buttons for plasma
« Reply #411 on: November 22, 2016, 04:05:49 AM »
Although its not your manufacturer, if you have a look at the hypertherm 65 manual, it provides additional air pressure (as dave says above) requirements for the longer hose.  https://www.hypertherm.com/Xnet/library/library.jsp?file=HYP115403&format=pdf


Blowback start is simply (yes I'm sure there is more to it than this but) .... a "floating" electrode within the torch tip, so that the air pressure drives the electrode gap, and the high voltage between the electrode and the tip generates the high voltage spark   (think spark plug, but with variable gap). edit: after reading Jim's post, the breaking away of the electode from the tip when the air pressure rises, which creates the spark

Hence the air pressure may be your problem with the longer hose given the floating electrode within your torch may not be moving back enough to trigger the arc or with-stain an adequate arc...... note that the current hyperthem range have an electronically variable air pressure (not the PMX45), so I suspect that the air pressure can be adjusted dynamically given any affects from the cutting surface which may cause some variance in the air pressure as the cutting height varies.

All of the above could however be bull.... so take with a pinch of salt as I'm no plasma industry employee just an owner of two (hypertherm) plasma cutters and have read a lot of the hypertherm manuals

blowback start waffle:
http://www.cnczone.com/forums/hypertherm-plasma/181858-cnc.html

better explanation on the HF + blowback start from Jim Colt:
http://www.tractorbynet.com/forums/welding/211108-plasma-cutter-choices-4.html
« Last Edit: November 22, 2016, 04:13:24 AM by robertspark »
Rob

Albert Einstein ― “If you can't explain it to a six year old, you don't understand it yourself.”

Offline Hood

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Re: Physical buttons for plasma
« Reply #412 on: November 22, 2016, 04:32:43 AM »
From that link, the one with Everlast guy in it, it says the Trafimet S series are blowback style so that is what I have.
As I said I tried different pressures, here is what the manual states

b) Check air pressure is around 4.5-5 bar (65-75PSI), excessive pressure will give bad
starting, pressure can be reduced to around 4.0 bar if necessary


I also used the flow meter on the torch itself and flow was more than adequate according to it so I must presume pressure likewise.

I will remove the extension and connect it to the central adapter and see if it works, if it does then it seems there may be a limit to the length of lead, if it doesn't then it could be an issue with the blowback parts in the torch itself.

When I asked for a 10m torch I was told they only have them in 6M but they could supply a joining box to extend, what this consisted of I am not sure but would think it just a pipe connection (double male) and 3 terminals to connect the safety wires and pilot arc wire but maybe not?

Offline Hood

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Re: Physical buttons for plasma
« Reply #413 on: November 22, 2016, 01:41:15 PM »
Did the first real job today, parts for a stainless hanging block. Was still using the hand torch and I have quite a bevel on the left and right sides but that is totally down to the torch being ouyt of alignment, other than that it went good.
Vid here
https://youtu.be/t1MEf8A50EU

After I cut the parts I haled the machine torch extension off and connected up the central adapter on the end and tried it out, seems to be working fine although it doesn't seem to be quite as good as the hand torch for some reason, then again never got much time to do further tests, that will have to wait for another day.

Offline Davek0974

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Re: Physical buttons for plasma
« Reply #414 on: November 22, 2016, 02:10:29 PM »
Nice, glad it's going at last :)

Bevel can be torch too high (wider at top) torch too low (wider at bottom) uneven (torch not true to surface)
Bridgeport Mill, Mach3 V062, CSMIO-IP/A controller, AC Servo Drives

Offline Hood

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Re: Physical buttons for plasma
« Reply #415 on: November 22, 2016, 02:18:38 PM »
Don't think it was torch height as the X axis moves were straight and they were sloping the same way on either side, like this /............./   I think if it had been height then it would bevel like this /........\  .
I can actually see the torch is not square, it was just a quick lash up to see if the problem was with the machine torch.

As said the machine torch worked fine on the couple of tests I did but it just seemed a wee bit different, can't really explain but more testing will let me know how it is performing.

Offline Davek0974

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Re: Physical buttons for plasma
« Reply #416 on: November 22, 2016, 02:30:34 PM »
Great, seems like you have it sorted then.

:)
Bridgeport Mill, Mach3 V062, CSMIO-IP/A controller, AC Servo Drives

Offline Chaoticone

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Re: Physical buttons for plasma
« Reply #417 on: November 22, 2016, 04:04:04 PM »
Nice Hood!  :)
;D If you could see the things I have in my head, you would be laughing too. ;D

My guard dog is not what you need to worry about!

Offline Hood

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Re: Physical buttons for plasma
« Reply #418 on: November 22, 2016, 06:12:46 PM »
Yes Dave, getting there, still have the THC to get sorted out and also the M31 issues but I am hoping a cleanup of the computer will help as it has been running Mach3 for a long time and was used as a testbed so all sorts of junk in there.

Thanks Brett :)

Offline Davek0974

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Re: Physical buttons for plasma
« Reply #419 on: November 23, 2016, 02:18:27 AM »
What axis were the ePid errors on with the M31?

Sounds similar to my Bridgeport issues with jogging in a tool change - instant ePid fault.
Bridgeport Mill, Mach3 V062, CSMIO-IP/A controller, AC Servo Drives