NEMA23 2.8amp X/Y steppers connected to Duet2 Wifi

Quadcells

Hi,
The NEMA23 steppers that I have been using are 2.8amps, If I use the rule of 80-85% current then that would be 2.24-2.38amps.
If I have plenty of cooling would this be good or should I be looking at the Duet3 or external drivers.
This is in a RailcoreII 300ZL (Duet2 wifi + Duex5 boards with dual extrusion so the Y carriage is about 760grams.

Veti

up to 2.4A
see
https://duet3d.dozuki.com/Wiki/Hardware_Overview

Stepper driver features Up to 2.4A peak current, up to x256 microstepping, optional x16 interpolation on x16 microstepping, stall detection

but it will require cooling

do you already have the duet2?

Quadcells

Yes I Duet2 and every so often I get over temp warnings on the Y stepper. So I think I need more cooling or bit the bullet and move to the Duet3.

Veti

how are you cooling the duet?

there should be a constant stream of air across the back.

its not officially recommended but i have found that fitting a heatsink on the chips helps further to reduce the temperature.

droftarts

@Quadcells You should be able to set the current at 2.4A. However, it will require cooling. See here for recommendations: https://duet3d.dozuki.com/Wiki/Hardware_Overview#Section_Cooling

There is thermal protection on the drivers. You will get a warning message if they go over 100C, and they will shut down at 150C (with another message).

Ian

Quadcells

Thanks for the iformation.
I do have a constant air flow on the back of the duet2 wifi and the Duex5 boards. I guess it's not enough.

fractalengineer

@Quadcells what steppers do you have? I got 2.8amps Nema23 on my railcore too, duet3 but I find running them at 65% current seems to work best; lower stepper temps, lower noise, even higher speeds thanks to lower back EMF.

Quadcells

@fractalengineer I have the LDO NEMA23 2.8amp and found that if I set the current below 80% I was skipping steps until I turned up the current.

fractalengineer

@Quadcells that's uncanny; what ref number exactly?

I had the standard ones with high impedance; not good at all for this high speed application but then I switched to the railcore special LDO-57STH56-2804MACRC with mm shaft and it went all gucci

Quadcells

@fractalengineer I have LDO-57STH56-2804MAC

Quadcells

@fractalengineer You said that you have the Duet3, do you like it on the RailcoreII.

dc42

@Quadcells said in NEMA23 2.8amp X/Y steppers connected to Duet2 Wifi:

Yes I Duet2 and every so often I get over temp warnings on the Y stepper. So I think I need more cooling or bit the bullet and move to the Duet3.

You might like to try moving the Y motor to driver 4 (labelled E1), especially if you are running the E0 motor at lower current. That will separate the two drivers running at high current, so that they don't heat each other up as much.

Alternatively, if you are only using one of the two Z motor outputs and Z is running at a lower current, you could swap X and Z.

Quadcells

@dc42 I currently use E1 for my second extruder stepper. But I could switch the two.

dc42

@Quadcells said in NEMA23 2.8amp X/Y steppers connected to Duet2 Wifi:

@dc42 I currently use E1 for my second extruder stepper. But I could switch the two.

If E1 is running at a lower current, that would be worth trying.

dc42

PS - does the airflow run along the back of the board, and preferably along the top of it too?

Quadcells

@dc42 I have a small fan blowing across the back of the board where the drivers are.

Quadcells

@dc42 ok I will try that too.E1 for Y stepper

fractalengineer

@Quadcells interesting looks like we got the same specs

I'm also using a 20T pulley (160steps/mm)

Love the duet3 so far; nice to build the railcore on a single board (+SBC)

The stealtchop is nice too; I use it often on PETG/TPU prints

dc42

@Quadcells said in NEMA23 2.8amp X/Y steppers connected to Duet2 Wifi:

@dc42 I have a small fan blowing across the back of the board where the drivers are.

Top and bottom of the board is best, if you can manage it, e.g. a 40mm fan at the edge of the board next to the VIN terminals.

Quadcells

@dc42 Thank you for the help. I will get back to this post soon with an outcome.