Good morning!

I know that this has been discussed several times already. I started this thread to collect the available closed loop options for the Duet3.

I have two custom large format printers in the making. One with a build volume of 1000x1000x1000mm for printing architecture models and one with 500x500x1000mm for printing speaker enclosures. With a Build volume this large speed and reliability are essential. Therefore, a closed-loop motion system is a "must have" for my clients.

For the Duet3 I have found the following options:

1. Duet3 + Duet3 Expansion 1XD + external closed loop stepper drivers that accept step/dir signals

2. @dc42 I am aware that there is a closed-loop extension board in the making for the Duet3. Is there already a rough estimate on the release date or beta test?

3. Is there an alternative "of the shelve" closed loop solution available that support the CAN FD protocol?

Cheers,
Max

@bearer @Phaedrux

I have solved the issue by installing the unstable version (DSF Version: 2.1.3) of Duet Software Framework on Raspberry Pi. and also reverting back to RC11

The guide links to the stable version of the DSF and latest version of the reprap firmware which, at least in my case is not compatible and will lead to the "DCS is unavailable" Error.

cheers Max

@Phaedrux Thank you!
After trying about a dozen different tutorials on how to install and configure motion I found one that worked for me.

Motion setup tutorial

Cheers
Max

@mikedc

Hey, thank you very much for sharing this. I will give it a try!

-Max

@owend said in Pressured air cooling controlled with servo and ball valve:

(...)I suspect it's actually coming from your M950 command on the previous line.
Either that are it's one of this SBC specific issues.

It's not the M950 command (I have checked by commenting out this line)

@owend said in Pressured air cooling controlled with servo and ball valve:

What happens when you run those commands individually from the console command line?

I get the same error message.

-Max

@o_lampe said in Pressured air cooling controlled with servo and ball valve:

You have written servoout and also servo_out.

Nope, this did not cause the error...

"Error: Failed to read code from macro config.g: Failed to parse major G-code number (lobal) in line 4"

;Valve Control
; Set up scaling variables {(output_end - output_start) / (input_end - input_start)}
M950 S1 C"io4.out"  ; assign GPIO port 1 to heater4 on expansion connector, servo mode
global InputStart = 0 
global InputEnd = 1
global OutputStart = 0
global OutputEnd = 90
global ScaleFactor = (global.OutputEnd - global.OutputStart) / (global.InputEnd - global.InputStart) ; no need for the math in this instance but it makes it clear how you arrive at the value.
global ServoOut = floor(global.ScaleFactor * (fans[0].actualValue - global.InputStart) + 0.5) + global.OutputStart ; calculate position required on sevo - use floor() to apply rounding
M280 P1 S{global.ServoOut} ; adjust valve position to reflect fan speed.

@owend

I am getting the following error after inserting your code in my config.g

"Error: Failed to read code from macro config.g: Failed to parse major G-code number (lobal) in line 85"

To me, it looks like the global variable are not recognized by the firmware:

I am using firmware version 3.3-b2.

@solo3d

Hey, I have tried exactly what you are describing with some success. I have switched back to just using a single extruder because I had some printing artifacts and needed to make sure that this is not caused by the hybrid extruder setup.

So I have to recall my setup steps from memory here:

1. setup two separate extruder motors in your config.g with their respective driver assignments, voltages, acceleration, jerk and e-steps depending on the gear ratio of each extruder.

2. create your tool and tell it to use extruder drive 1 and 2

; tool 0 
M563 P0 D0:1 H1 F1 ; tool 0 uses extruder drive 1 and 2 , heater1 and fan1
M568 P0 R0 S0 ; Set active and standby temperatures

3. Set tool mix ratios to 100% so that both extruders are used.

M567 P0 E1.00:1.00 ; Set tool mix ratios of tool1 to 100% for extruder 1 and 2

-Max

@o_lampe

So just to recap, these are my values:

• min_in = 0 (M106 S0 ->Fan off)
• max_in = 255 (M106 S255 -> Fan full on)
• min_out = 0 (M280 P0 S0 -> Servo at 0° -> valve closed)
• max_out =90 (M280 P0 S90 -> Servo at 90° -> valve fully open)

So my code should look like this ?

[**pseudo** code]
var scale_factor = {(90 - 0) / (255 - 0)}
var servo_out = {scale_factor * (fans[0].actualValue - 0) + 90}

M280 P0 S{var.servo_out}

I have not used G-Code meta commands before, so I would need a little help here to put this in clean meta code and make this work.

-Max

@mikedc

Hey, thank you very much for sharing this. I will give it a try!

-Max

@phaedrux
Can you please post the link to the wishlist post? I would like to follow the thread.

-Max

Hey, I am sorry to reheat this topic.

I have been using magnetic proportional valves for some time with limited success.
They are hard to control with the duet right now. Furthermore, they tend to heat up during longer use which makes them even harder to control. Since they are also very expensive I switched back to RC-servos and ball valves.

Can a demon.g be used to translate the M106 Fan speed into a Servo position?
In my case I need 0%-100% fan speed to equal 0°-90° Servo position. (Or stepper position as an alternative? )

@lael What solution are you using right now?

-Max

Good morning!

I know that this has been discussed several times already. I started this thread to collect the available closed loop options for the Duet3.

I have two custom large format printers in the making. One with a build volume of 1000x1000x1000mm for printing architecture models and one with 500x500x1000mm for printing speaker enclosures. With a Build volume this large speed and reliability are essential. Therefore, a closed-loop motion system is a "must have" for my clients.

For the Duet3 I have found the following options:

1. Duet3 + Duet3 Expansion 1XD + external closed loop stepper drivers that accept step/dir signals

2. @dc42 I am aware that there is a closed-loop extension board in the making for the Duet3. Is there already a rough estimate on the release date or beta test?

3. Is there an alternative "of the shelve" closed loop solution available that support the CAN FD protocol?

Cheers,
Max

@dc42

I am glad to hear that! Thank you very much for your feedback.

-Max