Trying to set up a custon CNC with duet2 wifi.

[A Former User]

Hi, I am in the process of setting up a custom made CNC. Its 4'x8' with a 2.2kw spindle and vfd. I am also using 1 Nema23 High Torque motor on the Z, 1 standard Nema23 on the X carriage and 2 standard Nema23 motors on the Y carriage. I also have a 450W 24V power supply. Will I need any other electronics and how do I configure the duet. I do have a 3D printer with a duet2 wifi. Is the programming roughly the same? Also would I need High-Power Stepper Motor Driver to run the motors. The High Torque Nema23 has a Rated current 4.2A & resistance 0.9ohms and the other Nema23's are Rated current 2.8A & resistance 1.13ohms. If someone can point me in the right direction I would appreciate it. Thank you Rich

[droftarts]

@chichirod start with the rather brief https://duet3d.dozuki.com/Wiki/Configuring_RepRapFirmware_for_a_CNC_machine

I think you’ll need to use an external driver on the 4.2A motor if you want performance out of it. The other two should be okay, but see https://duet3d.dozuki.com/Wiki/Choosing_and_connecting_stepper_motors

Ian

[3DPMicro]

You will need an external driver for your 4.2 amp stepper. If your Z is lead or ball screw driven consider that there is a lot of force multiplication with that arrangement. Using a 10mm lead, ball screw and 60oz/in nema 17 I get around 50lbs of force. About double that for a 5mm lead so one of the 2.8 amp, 23's may be more than adequate.
I used the firmware for the Workbee CNC and tweaked the settings for my mill. It includes touch probe and work offset macros
You didn't mention endstops and you may need a signal converter and some configuring for the VFD. What input does it require?

[jay_s_uk]

@chichirod
Have you already purchased the duet 2?

[dc42]

Duet 3 can drive that high torque Nema 23 motor directly. It also has a 5V PWM output suitable for direct connection to a PWM-to-VFD converter.

As has already been said, Duet WiFi/Ethernet can drive the 2.8A motors directly, but not the 4.2A one, so you would need to use an external driver for that one.

[A Former User]

@dc42 if I read this correctly then the duet3 should be able to handle everything but with the duet 2 I would need external drivers.

[A Former User]

@jay_s_uk no not yet.

[A Former User]

@3DPMicro ok thank you. I’ve already purchased the motors so I would rather not buy others as far as the input for the vfd I’ll have to get back to you on that one. Thank you for your help.

[A Former User]

@droftarts ok thank you. I’ll read those articles.

[jay_s_uk]

@chichirod I would go for the duet 3 if it's within your budget

[A Former User]

@jay_s_uk yes I think that’s the way I’m definitely leaning