Controller hardware suggestions for first DIY build

[quote="snowgoer540" post=183881
If you don’t mind taking it apart and switching it to 20:1, I’d use (and PCW recommended) that divider setting and a THCAD-10. It gives you 0-200v range where your max cutting voltage is somewhere around 150-170v. They all have the same 500v over voltage. So that combo gives the highest resolution.[/quote]

In this case would I need 2ea of the THCAD -10 units?

rodw wrote:

Yes. 50:1 will give a maximum scale of 250v to cover the useful cutting range but the THCAD-5 can handle 500v indefinitely for safety.

And also yes, grab the Mesa common connector you linked to. You can connect your 24V logic power + and - to the separate halves and then you can patch the power to wherever you need to for any inputs or outputs. It makes for a very compact design.

Got it. I have ordered some various drivers boards to experiment with. I also bought a G540 unit. So I have now jumped into the deep end, at least that's what it feels like.

As far as resistors you mentioned, here is what I put on will-call at my local dealer for Monday. I could not find the 90ohm at 5W so I got an 82ohm, will that work?

www.alliedelec.com/product/ohmite/45f25ke/70023375/

www.alliedelec.com/product/ohmite/25j25ke/70023237/

www.alliedelec.com/product/rcd-component...25-394-jtw/70183397/

www.alliedelec.com/product/bc-components...08209jac00/70122925/

I also ordered 2ea of these filters:

www.alliedelec.com/product/schurter/3-103-713/71168279/

Good advice from Snowgoer. I don't have a Hypertherm so don't fully know their range. Just check your manual or open the machine before you order as some of the earlier ones don't allow the divider to be changed.

I think the accuracy probably also comes from the lower dividing at the plasma cutter as well as the calculated full scale. I've used 160v to 300v on the machines I have owned and I've not seen a difference in performance. Its still darn accurate! (currently using THCAD-10 and 30:1 = 300 V full scale). My maximum cut volts at 120 amps, 25mm material is 173 volts.

I'm going to rethink how to word that simple 1 line of advice. Then it gets complicated

rodw wrote:

Good advice from Snowgoer. I don't have a Hypertherm so don't fully know their range. Just check your manual or open the machine before you order as some of the earlier ones don't allow the divider to be changed.

I can change my unit between these five divider settings.
20:1
21.1:1
30:1
40:1
50:1

I already placed the order for 2ea THCAD-5 ... should I ask if I can change that to 2ea THCAD-10? Or do I need one of the THCAD-5s for something else? I am getting sort of dizzy. Perhaps someone with a similiar setup has a schematic I could look over.

With all those divider settings you could use either type

rodw wrote:

Normally if a motor has no data sheets, I'd say buy another motor but heck you have got them now.
I would probably get Longs Motor DM542A drives

I just ordered 4ea of these to use with my 7I76E card. DM542A

I will use my G540 with something else, I need to get my table running with LinuxCNC soon in order to begin working with the pneumatic actuators. Do you have any wiring diagrams for this stepper and the 7I76E?

Its very easy. Just connect the 4 step and direction wires. and the 48v power and shielded wires to the motor. Connect the shield to the cabinet frame ground and leave shield at the motor end unconnected.

DO NOT attach any wires to the DM542 enable connector.

rodw wrote:

Its very easy. Just connect the 4 step and direction wires. and the 48v power and shielded wires to the motor. Connect the shield to the cabinet frame ground and leave shield at the motor end unconnected.

DO NOT attach any wires to the DM542 enable connector.

Are you describing the wires between the DM542A and the motor?

Which wires run between the DM542A and 7I76E and which wires run between the motor and the DM542A?

48v to DM542A . Connect the motor to the driver using a seperate shielded cable to each motor and the shield connected as I mentioned. Size the wires to carry the current given the length.

Then its just a matter of connecting +step & -step and +dir & -dir on the 7i76e to the DM542a. Hook up + to + and - to - for the step and direction signals

Do not use the DM542a ENA signal at all.