Selection of Duet board - 6HC or 6XD for closed loop steppers

[selva_tvi]

Hi all,

Planning to build IDEX-500x500 with 'Dual Markforged IDEX Kinematics'. (Muldex style, but custom made).

Some deeper questions. Your answers will support me to build the printer.

Stepper motors - X-01 and U-01, Dual Y, Triple Z axis and Two Extruders - Total 09 motors

The customer is insisting on Closed Loop Steppers. Planning to use Nema 23 closed loop stepper from the below link:
https://www.omc-stepperonline.com/ts-series-1-2-nm-170oz-in-1-axis-closed-loop-stepper-cnc-kit-nema-23-motor-driver-w-2m-cable-1-cl57t-s12
It is bundled with Motor, Driver and extension cables.
Question - The above Nema 23 stepper motor is having:
Phase Resistance: 0.45ohms
Inductance: 1.3mH ± 20%(1KHz)
Will it be sufficient to drive?

Following are the ideas for the boards.

Option 1 -
Duet 3 Mainboard 6XD - 01 nos + Duet 3 Toolboard 1LC - 02 nos + Duet 3 Tool Distribution Board - 01

Duet 3 Mainboard 6XD - In this planning to connect the following :
X - 01 - Closed loop Nema 23
U - 01 - Closed loop Nema 23
Y - 01 - Closed loop Nema 23 (Connecting in series for 2 motors)

Z - 03 - Open loop Nema 23

Duet 3 Toolboard 1LC - 02 nos - To connect the extruders.

Duet 3 Tool Distribution Board - 01 - To connect the Tool boards.

Here the main question is -

1. Duet 3 Mainboard 6XD - Will it take the Closed Loop stepper connections directly? I remember it takes the external stepper driver signal.
   But what about Closed Loop steppers?
2. Is Tool Distribution Board mandatory?

Option 2 -
Duet 3 Mainboard 6HC - 01 nos + Duet 3 Expansion 1HCL - 03 nos

Duet 3 Mainboard 6HC - In this planning to connect the following :
Z - 03 - Open loop Nema 17
E - 02 - Open loop Nema 17

Duet 3 Expansion 1HCL - 03 nos -
X - 01 - Closed loop Nema 23
U - 01 - Closed loop Nema 23
Y - 01 (Connecting in series) - Closed loop Nema 23

1. Is the Duet 3 Expansion 1HCL board available in the market?

Kindly give your suggestions on the above.

Thanks in advance.

[T3P3Tony]

@selva_tvi

The 6XD connects to external motor drivers, those can be open loop or closed loop steppers/servos whatever as long as the drivers accept step/dir inputs.

The 1HCLs connect to stepper motors that have a quadrature encoder built in. They are available.

[selva_tvi]

@t3p3tony

Thanks.

So, the 6XD also will be able to drive the 'stepper motors that have a quadrature encoder built in', isn't it?

Also, can you please confirm the below?

The customer is insisting on Closed Loop Steppers. Planning to use Nema 23 closed loop stepper from the below link:
https://www.omc-stepperonline.com/ts-series-1-2-nm-170oz-in-1-axis-closed-loop-stepper-cnc-kit-nema-23-motor-driver-w-2m-cable-1-cl57t-s12
It is bundled with Motor, Driver and extension cables.
Question - The above Nema 23 stepper motor is having:
Phase Resistance: 0.45ohms
Inductance: 1.3mH ± 20%(1KHz)
Will it be sufficient to drive?

[o_lampe]

@selva_tvi
The motors have an encoder with 1000PPR only. The shaft has 8mm diameter, which will make it difficult to find small pulleys.
The combination of both might lead to low accuracy.
You could add a gearbox, but backlash compensation isn't an option in RRF (yet?)
Also the gearbox will slow down the printer, because the encoder output frequency is much lower than the driver pulse frequency. (60kHz vs. 200kHz)

I could see them as Z-motors, if your 500x500 bed is really heavy. But for XYU, they're not the best.

//edit after a quick search for 1000PPR I found a few threads like this one

[T3P3Tony]

@selva_tvi the 6XD can interface with the stepper drivers you linked fine.

Whether the motors are suitable for your application depends on step rate and the torque/speed required.

[selva_tvi]

@o_lampe

Can you please suggest some motors which will suit my requirements on XYU?

In the link which you have provided, it is having Nema 17 closed loop steppers. That will not match with my requriement.

[dc42]

@selva_tvi 1000ppr is fairly standard. The Duet3D EXP1HCL driver can get 4000 cpr out of them, although the accuracy of the intermediate steps is reduced. I can't vouch for the StepperOnline driver because I have no experience of it. If you read the manuals, they may say whether or not you can set the steps/rev to 2x or 4x the cpr.