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What to do with old plasma table

I'm getting ready to order Myplasm. Anyone got an idea what a voltage divider is for / what it does? Do I need one?
In the Linuxcnc world it basically lowers the RAW plasma voltage to a voltage more suited to be read by the THC board.
For the MESA THC boards you just use resistors to create the "divider".
 
In the Linuxcnc world it basically lowers the RAW plasma voltage to a voltage more suited to be read by the THC board.
For the MESA THC boards you just use resistors to create the "divider".
Gotcha. Doesn't look like I actually need it per the Myplasma diagram though?
 
Gotcha. Doesn't look like I actually need it per the Myplasma diagram though?


You don’t necessarily need it but it’s a good idea. The THC system off of my plasm has it ready to decode.

My hypertherm plasma provides a divided voltage supply from the CPC cable out the back.
 
My hypertherm plasma provides a divided voltage supply from the CPC cable out the back.

That's another thing I'm confused about. My machine appears to have some sort of arc voltage connection. Do I still need the shielded ohmic retaining cap in that case?

1710799518665.png
 
I'm having second thoughts about Myplasm. Just kind of seems risky to not have US-based support / parts. Seems like a great product, but I've been bit in the butt nearly every time I buy something that only offers overseas support.
 
That's another thing I'm confused about. My machine appears to have some sort of arc voltage connection. Do I still need the shielded ohmic retaining cap in that case?

1710799518665.png
I was going to add if you have the CNC hypertherm you might not the divider but with the RAW arc voltage 200+ volts DC you probably don't want that voltage around your CNC equipment. I put the divider inside my cutter so I only have 10v cable out of the cutter.

1710799990759.jpeg
 
I'm having second thoughts about Myplasm. Just kind of seems risky to not have US-based support / parts. Seems like a great product, but I've been bit in the butt nearly every time I buy something that only offers overseas support.
Whats second choice?

I was curious if you could use Mach4 with MESA boards.
 
I'm having second thoughts about Myplasm. Just kind of seems risky to not have US-based support / parts. Seems like a great product, but I've been bit in the butt nearly every time I buy something that only offers overseas support.
I'll say it is really popular.
Automation Technologies is selling all of it, the EAgle guy and many others.

Here's another option.



Founded in 1979 by two Penn State graduates, a computer programmer and a electronics engineer with the vision to create PC based CNC control electronics and software that was user friendly, reliable and affordable. Since 1979 Centroid has grown over the years and supplies innovative CNC Control systems to both a OEM and DIY customer base with a wide variety of CNC applications. Located in Howard, Pennsylvania, USA.Centroid designs and manufactures its own turn key 5-axis CNC machining centers along with CNC control kits and CNC components for both the OEM CNC and DIY CNC marketplaces.


Webpages:
CNC Control systems centroidcnc.com
5 Axis CNC machine tools centroidperformanceracing.com
DIY CNC control kits centroid_diy
Centroid CNC Community Support Forum Centroid Community CNC Support Forum - Index page

Facebook page CENTROID CNC | Howard PA
Youtube Channel https://www.youtube.com/centroidCNC


CENTROID
159 Gates Rd.
Howard, PA 16841 USA
(814) 353-9256
www.centroidcnc.com



1710800815189.png
 
Whats second choice?

I was curious if you could use Mach4 with MESA boards.
No clue. I really like the product, but every time I have a question and go to their website, my browser has to translate it for me and I can never find the answer. Their main form of support seems to be a referral to their FB support page, which they label as "unofficial" and there's only 3600 members. Every time adds to my apprehension.
 
No clue. I really like the product, but every time I have a question and go to their website, my browser has to translate it for me and I can never find the answer. Their main form of support seems to be a referral to their FB support page, which they label as "unofficial" and there's only 3600 members. Every time adds to my apprehension.
Probably why the Eagle guy is selling at the premium price.

I think you are right to be apprehensive though...
 
I'll say it is really popular.
Automation Technologies is selling all of it, the EAgle guy and many others.

Here's another option.



Founded in 1979 by two Penn State graduates, a computer programmer and a electronics engineer with the vision to create PC based CNC control electronics and software that was user friendly, reliable and affordable. Since 1979 Centroid has grown over the years and supplies innovative CNC Control systems to both a OEM and DIY customer base with a wide variety of CNC applications. Located in Howard, Pennsylvania, USA.Centroid designs and manufactures its own turn key 5-axis CNC machining centers along with CNC control kits and CNC components for both the OEM CNC and DIY CNC marketplaces.


Webpages:
CNC Control systems centroidcnc.com
5 Axis CNC machine tools centroidperformanceracing.com
DIY CNC control kits centroid_diy
Centroid CNC Community Support Forum Centroid Community CNC Support Forum - Index page

Facebook page CENTROID CNC | Howard PA
Youtube Channel https://www.youtube.com/centroidCNC


CENTROID
159 Gates Rd.
Howard, PA 16841 USA
(814) 353-9256
www.centroidcnc.com



1710800815189.png
Phone support is $120/hr! :eek:
 
I'm not trying to Spam you just linking all the stuff I consider is good just too pricey for my budget.
 
I'm not trying to Spam you just linking all the stuff I consider is good just too pricey for my budget.
No, I appreciate all the info / links / help you've offered. Just curious what you consider the alternative if all this stuff is too pricey though?
 
No, I appreciate all the info / links / help you've offered. Just curious what you consider the alternative if all this stuff is too pricey though?
Since I am extreme tight ass this is what I used and why.

LinuxCNC is free open source.
MESA FGPA 7i96s controller $149
MESA THCAD-10 (replaced by THCAD2) $79

That's all you need for CNC stuff, stepper motors/drivers are the same, power supplies, limit switches etc. all the same
I am over simplifying this please understand but this is the "core" of the machine.
There is alot of talk that the linuxcnc is a superior "real time" controller vs the Mach3 alternative and honestly all that shit is over my head.
But it does work well and while the Linux computer part kicked my ass for a long time because I was trying to use a NOT SUGGESTED laptop, that is not to be taken lightly. I am computer dangerous(dumbass) and there was a lot to learn but I was able to do it.

If you know up front you only want windows I am the last guy to talk you out of that because I know how much of ass whip Linux can be.

And for transparency I bought the SheetCAM software for $145 to handle the CAM/nesting etc.
 
I think I finally grasped this concept. Correct me if I'm wrong:
  • Floating head w/switch is essentially a touch sensor to zero the Z based on material height?
  • Ohmic sensing uses the shielded ohmic retaining cap (or I guess just the tip of the torch itself?) to also act as a touch sensor to zero the z?
  • Floating Head and Ohmic basically do the same thing in different ways, therefore no point in having both?
  • Arc Voltage is real-time height sensing during the cut and does not require any special hardware as far as the torch goes. My Powermax 1000 provides an undivided 300vdc arc voltage signal, which is probably high and needs to be divided down?
 
I think I finally grasped this concept. Correct me if I'm wrong:
  • Floating head w/switch is essentially a touch sensor to zero the Z based on material height?
  • Ohmic sensing uses the shielded ohmic retaining cap (or I guess just the tip of the torch itself?) to also act as a touch sensor to zero the z?
  • Floating Head and Ohmic basically do the same thing in different ways, therefore no point in having both?
  • Arc Voltage is real-time height sensing during the cut and does not require any special hardware as far as the torch goes. My Powermax 1000 provides an undivided 300vdc arc voltage signal, which is probably high and needs to be divided down?
Exactly!

The ohmic is supposed to be much faster in probing, that probably matters much more in production environment with a lot of pierces.

Your THC voltage sensing hardware will dictate if the voltage "needs" to be stepped down but I decided I didn't want a 300v cable in my CNC controller cabinet or running to it so I stepped it down to 0-10v using the two resistors in my pic above.

According to this page of the manual you'll definitely need a voltage divider, the THC interface has a 20v maximum.
1000012084.jpg
 
my last two plasmas you can just plug into the raw arc voltage on the board
probably one of the easier parts of the set up
 
my last two plasmas you can just plug into the raw arc voltage on the board
probably one of the easier parts of the set up
Did they have the cpc ports?

When I was looking it seemed like you could get a kit to add the port to the cutter but for the price $150? It didn't seem worth it.

Edit: something like this
 
Exactly!

The ohmic is supposed to be much faster in probing, that probably matters much more in production environment with a lot of pierces.

Your THC voltage sensing hardware will dictate if the voltage "needs" to be stepped down but I decided I didn't want a 300v cable in my CNC controller cabinet or running to it so I stepped it down to 0-10v using the two resistors in my pic above.

According to this page of the manual you'll definitely need a voltage divider, the THC interface has a 20v maximum.
1000012084.jpg
That's weird. Earlier in the same manual it states that it can read up to 300vdc.
1000014470.jpg
 
That's weird. Earlier in the same manual it states that it can read up to 300vdc.
1000014470.jpg
I'm not sure what to make of that. The red text states any voltage above 20 will damage the "interface".

Might need to get some clarity on this.
The picture of the interface seems to say it can handle raw voltage to 300v

1000012088.jpg
 
Last edited:
Really you are talking .50 worth of resistors either way.
If you didn't want to bother I think I'd mount that THC interface directly to the plasma cutter and just run the serial cable (cat6) or something to the cutter. Simplify the cabling that way.
 
Did they have the cpc ports?

When I was looking it seemed like you could get a kit to add the port to the cutter but for the price $150? It didn't seem worth it.

Edit: something like this
no it was on there already
 
I'm not sure what to make of that. The red text states any voltage above 20 will damage the "interface".

Might need to get some clarity on this.
The picture of the interface seems to say it can handle raw voltage to 300v

It can go either way. You just hook it up to the different pins. One is 20v max, the other 300.
 
It can go either way. You just hook it up to the different pins. One is 20v max, the other 300.
Makes sense, maybe the translation from Not English to English left out some details.
IT is annoying that the pictures in the manual aren't translated to English.
 
Really you are talking .50 worth of resistors either way.
If you didn't want to bother I think I'd mount that THC interface directly to the plasma cutter and just run the serial cable (cat6) or something to the cutter. Simplify the cabling that way.
I think I would use shielded cable, or shielded CAT6, not plain CAT6.
Slightly less chance of interference that way.

Aaron Z
 
Since I am extreme tight ass this is what I used and why.

LinuxCNC is free open source.
MESA FGPA 7i96s controller $149
MESA THCAD-10 (replaced by THCAD2) $79

That's all you need for CNC stuff, stepper motors/drivers are the same, power supplies, limit switches etc. all the same
I am over simplifying this please understand but this is the "core" of the machine.
There is alot of talk that the linuxcnc is a superior "real time" controller vs the Mach3 alternative and honestly all that shit is over my head.
But it does work well and while the Linux computer part kicked my ass for a long time because I was trying to use a NOT SUGGESTED laptop, that is not to be taken lightly. I am computer dangerous(dumbass) and there was a lot to learn but I was able to do it.

If you know up front you only want windows I am the last guy to talk you out of that because I know how much of ass whip Linux can be.

And for transparency I bought the SheetCAM software for $145 to handle the CAM/nesting etc.
So, should that be able to be used on a CNC mill as well (assuming the voltages for the motors match)?

Seeing a CNC mill that says it needs a motherboard and wondering if that would let me upgrade it from what appears to be a 1980s vintage control system to something a little newer (and possibly sell off the old control boards to offset my cost).

Aaron Z
 
So, should that be able to be used on a CNC mill as well (assuming the voltages for the motors match)?

Seeing a CNC mill that says it needs a motherboard and wondering if that would let me upgrade it from what appears to be a 1980s vintage control system to something a little newer (and possibly sell off the old control boards to offset my cost).

Aaron Z
Exactly, LinuxCNC was a machine controller first, the plasma GUI was added later.

There is a LOT of possibility with existing machine integration using the MESA cards, they have boards with many more I/Os, encoders etc. and the boards can daisy chain if more I/O's are needed.
Fully customizable and the owner of MESA will build custom firmware (if needed) to do things that are not currently offered.

Check out the Linuxcnc forum for some examples.
A good youtube channel is RotarySMP a airplane mechanic in Austria I think.
here's his build thread converting a MAHO mill to linuxcnc.

 
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