ABOUT THC
03 Jun 2019 13:52 #135750
by AgentWD40
So for the THCAD-10 what is the recommendation as to where to mount the card? Put it in your control box as you had done, mount it in it's own enclosure next on the plasma machine, or doesn't really matter and just do what's most convenient? If it is in its own enclosure should that be a metal enclosure?
By the way:
Hypertherm grounding pdf: xnet.hypertherm.com/Xnet/library/download/?file=HYP103900
Torchmate:
torchmate.com/uploads/downloads/Technica...nding_TM_Control.pdf
torchmate.com/uploads/support/pdfs/Machi...ng%20Information.pdf
By the way:
Hypertherm grounding pdf: xnet.hypertherm.com/Xnet/library/download/?file=HYP103900
Torchmate:
torchmate.com/uploads/downloads/Technica...nding_TM_Control.pdf
torchmate.com/uploads/support/pdfs/Machi...ng%20Information.pdf
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03 Jun 2019 14:11 - 03 Jun 2019 14:13 #135753
by Clive S
Rod Thanks: I am happy with the grounding , EMI and high voltage issues . If the THC won't fit into the case I will mount a metal box on it with the THC inside.
I am not sure where to exactly connect the input of the THC to ie is it straight from the output of the plasma -ve and +ve terminals via say 100k resistors in each leg? Also do I use the 300 or 0 thc
Photos:- photos.app.goo.gl/u3LRnzeJQTSEFMjV8
The arc voltages are not very healthy (and probably lethal). If you have the 300 inside the case everything is contained and just a 5 volt power in and a 5 volt frequency out is all that is required.
But if you bring the wires outside it is a good idea to use a THCAD-10 and add the scaling resistors on the inside of the case so the voltage is no longer lethal in the outside world.
The other thing going for the THCAD-10 is that you can control the full scale reading so you might find with your machine you can get away with a 150 volt or 200 volt range so you have greater resolution in the decoded torch voltage.
Rod Thanks: I am happy with the grounding , EMI and high voltage issues . If the THC won't fit into the case I will mount a metal box on it with the THC inside.
I am not sure where to exactly connect the input of the THC to ie is it straight from the output of the plasma -ve and +ve terminals via say 100k resistors in each leg? Also do I use the 300 or 0 thc
Photos:- photos.app.goo.gl/u3LRnzeJQTSEFMjV8
Last edit: 03 Jun 2019 14:13 by Clive S. Reason: added text
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03 Jun 2019 16:56 #135762
by billykid
Thanks Rod, I preferred to put it there because the 7i30 has no differential input and I do a long stretch I'm afraid of disturbances .. I could put a differential receiver not a problem but I'll see if there are any disturbances, I have oscilloscopes.
I have only the doubt of the external resistance, I have some problem with the language and I have not understood correctly if it goes one on the negative.
now I have a divider that would also give the right tension but to what I read they say they do different.
if you can make a sketch of the scheme I understand that without any problem. pneumatic torch without hf is my plasma.
I have only the doubt of the external resistance, I have some problem with the language and I have not understood correctly if it goes one on the negative.
now I have a divider that would also give the right tension but to what I read they say they do different.
if you can make a sketch of the scheme I understand that without any problem. pneumatic torch without hf is my plasma.
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04 Jun 2019 19:43 #135854
by rodw
Gyus, when we talk about the resistors, it is not some arbitrary choice.
Follow the instructions on Page 6 "Extending the input range" of the THCAD Manual . Split the calculated resistance in two and insert that value on each electrode signal.
Clive. That looks identical to one we tried to repair. One of the mosfets in that row self diagnosed a problem with some smoke signals. After we tried it again, the Whole machine went of with a Huge bang and issued a cloud of smoke so it was consigned to the tip! Sorry but I threw the torch out. It is a High Frequency Pilot Arc Start I think. Eg. It will fire in the air. Lots of EMI.
Follow the instructions on Page 6 "Extending the input range" of the THCAD Manual . Split the calculated resistance in two and insert that value on each electrode signal.
Clive. That looks identical to one we tried to repair. One of the mosfets in that row self diagnosed a problem with some smoke signals. After we tried it again, the Whole machine went of with a Huge bang and issued a cloud of smoke so it was consigned to the tip! Sorry but I threw the torch out. It is a High Frequency Pilot Arc Start I think. Eg. It will fire in the air. Lots of EMI.
The following user(s) said Thank You: Clive S
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04 Jun 2019 22:02 #135868
by Clive S
Thanks Rod.
I know its not a good machine but it was free. The on/off switch was faulty but I had a new one and now it powers up but I can not test it until the new torch arrives from China. I have started to build the machine 1250x700 cut size with gantry across the 1250 using twin nema 34 with a on racks. So gantry squaring needed .
What I gather is I will need a THC10 + 7i96 that I have used in the past.
I know its not a good machine but it was free. The on/off switch was faulty but I had a new one and now it powers up but I can not test it until the new torch arrives from China. I have started to build the machine 1250x700 cut size with gantry across the 1250 using twin nema 34 with a on racks. So gantry squaring needed .
What I gather is I will need a THC10 + 7i96 that I have used in the past.
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04 Jun 2019 22:55 #135872
by tommylight
Replied by tommylight on topic ABOUT THC
Clive, for that size you could have used 6mm wide GT2 belts with 15 or 16 or even 20 tooth GT2 pulleys on Nema 17 motors, the only caviat is to use 2 motors to drive the gantry. With pouloulu or whatever micro stepping drives set at 4 or at 8 the micro stepping it would be capable of running at over 20 meters/minute.
With Nema 34 you will get a lot of vibrations and that would show in the cuts.
Nema 23 at any length would be perfect but need 1/16 micro stepping to run smooth with that weight.
Side info, there are at least 3 lengths for any Nema size of motors, never studied it, but some refer to it as double and triple length, some just give the current with no mention of length.
Currently I think I have single and double Nema 17, all 3 lengths of Nema 23 and 34, so I can take some pictures if anyone is interested.
Motor inertia is different for the similar holding torque of the motors.
With Nema 34 you will get a lot of vibrations and that would show in the cuts.
Nema 23 at any length would be perfect but need 1/16 micro stepping to run smooth with that weight.
Side info, there are at least 3 lengths for any Nema size of motors, never studied it, but some refer to it as double and triple length, some just give the current with no mention of length.
Currently I think I have single and double Nema 17, all 3 lengths of Nema 23 and 34, so I can take some pictures if anyone is interested.
Motor inertia is different for the similar holding torque of the motors.
The following user(s) said Thank You: Clive S
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