I also do lots of other DIY electronics.

For audio amplifiers, and circuits where ground loops can cause some very undesirable things, particularly since there are a lot of places that can cause ground loops in audio equipment, it seems to be pretty standard practice to have an isolator between the DC ground and actual earth.

I have built a bunch of circuits from Eliott Sound Productions, pre-amplifiers, signal processors, and audio amplifiers. I made quite the sound system with his circuits.

In this schematic, you can see in the bottom, the parts used for the loop isolator. D1, D2, R1 and C1 are all in parallel providing a nominal break between earth and the DC ground. This one is for a dual amplifier supply, but shows that the AC earth should have at least a modicum of isolation from the DC ground. This is also true for single-rail supplies. Failing to do this can result in audible noise in audio circuits.

If you omit D1 and D2, this will still work as an isolator, however should a large potential build up, you might end up burning R1, which would normally be a 0.25W device. The diodes protect R1 by acting as a dead short for voltages above the Vf of the diode, typically a bit under a half volt.

The Meanwell diagram seems to only use C1. This is probably adequate if there is no electrical fault elsewhere, but we're doing this in case there IS a fault elsewhere.

Re-sizable controls. I might want a fairly control dense screen on my RPi 480X320 screen with a trackball, or I might want only a few key buttons if I'm using the same in a 5" touchscreen. Kind of different if I'm displaying on a 4k monitor.

I commonly use an RPi with a 1280X720 7" screen, my phone (5" 1080X1920 or 1920X1080 screen) or my media PC (40" 4k screen) with DWC now.

The phone is the most maddening, but the one that I am most likely to use for babystepping adjustments.

For me thought the biggest thing that I'd like to see is user levels. One level where you can print pre-stored files, one level where you can upload macros and files, and one where you can update firmware, and main configuration. (Let the kids print another object, daily use, and admin privs.) Yeah, I'm aware that with "Gcode everywhere" uploading a Gcode file can do whatever mucking with the configuration files can do, but at least it can be reset with a power down. (I'm a network admin for my day job. Proper user sandboxing is something that I like.)

No way I'm granting Internet access to any device that doesn't need it.

My Duet can talk to my LAN, but cannot talk to the Internet. Even if you can somehow convince something else on my LAN to talk to the Duet for you, the Duet isn't going to talk to the Internet. My Raspberry Pi running its RetroPi distro can't talk to the Internet directly. I download images and updates to a more secure server on the LAN, then download to the Pi from there.

I don't need access to my 3D printer from the Internet. I don't think I'd even leave it powered on while I'm not there. Maybe (but probably not) if I were leaving the house to go somewhere and finish a 3D model which I wanted to start printing before I come home... But then what to do if the first layer messes up? I suppose that I can put a webcam on the printer to see, and abort the print, but it's not like I can scrape off the ruined layer, re-prepare the bed and start again. It would be a one-shot "works or doesn't" attempt, and something rare enough that I can't see setting up for it. Besides, there are plenty of secure enough ways to remote control a PC with reasonable security, which will then be able to access other machines on the LAN.

I figured that it's only a matter of time before things like this become hacker targets.

I'm not concerned about someone stealing my gcode files, and I believe that I have reasonable enough safeguards in place to keep someone from starting a fire with my 3D printer.

Test that the wires go where you think that they do. Test for continuity with it disconnected from the Duet. You should have continuity between the black and red wires, and between the blue and green wires, but not between any other pairs.

Check that you have the jumpers on the second Z motor connector. If that is open, your motor will not move.

You have the choice of Vin (Whatever your main power supply is) or 5V as selected by a jumper on-board. Alternately, if you have another power supply voltage (Say, your Vin is 24V, and you have a 12V converter) you can connect that to the jumper instead and power your fans that way.

Most people select fans to match their main power supply.

I've moved all of my stuff (Except for some half-baked things that weren't any good) onto Prusaprinters.org myself. Probably moves some of the crap over, too, honestly.

I've recently become a little more serious about my CAD development, so hopefully better things coming.

Okay, so looking at your printer, it appears that the bed moves in the Y axis.

Since you have a Bowden extruder, the X axis is going to be much lighter than the heavier bed, so increasing the moving mass in the Y axis is going to slow down your printing, in that you will need to use lower values for accel in the Y axis with the heavier mass, all else equal.

However, if you are upgrading from 12V to 24V, you might find that your motors will deal with it better overall, though there will still be some ringing, just as a part of the nature of the drive belts. Well, any drive system, really.

I added a couple of pieces of aluminum bar to my Y axis as a part of getting my Piezo Andromeda sensors set up. Maybe a couple hundred grams, I didn't weigh them specifically. It didn't seem to make a noticeable difference in the ringing that I get in the Y axis, but I also print somewhat slowly, since the leadscrew drive configuration that I use doesn't lend itself to very high speed moves. I hardly ever have anything above about 75mm/s, and perimeters are never over about 50mm/s.

How much does your mirror weigh? If you can print without it on the aluminum, that's probably a better solution anyway. Glass is terrible for thermal properties. I use it myself because I like the super-smooth first layer, but I'm looking at solutions to print without it, since almost everything that I print can tolerate a slightly rougher surface texture, and even the 2mm glass that I'm using has its weight to consider.

In your position, I would probably use the 5mm plate, and do away with the glass. Use a PEI sheet or similar instead, and you'll have more even heating, and probably better adhesion with most prints. It's likely that you'll be much happier with the overall result, even if you have to slow down your Y accel by a few percentage points.

From your post, I'm assuming that you have 2 Z stepper motors, and that the printer worked, but you (temporarily) removed one motor, and when you reinstalled it, you're getting inconsistent results.

Is it consistent? Is it always the same motor that is lower at the end of the print, or does it go back and forth?

I'm sure that you checked, but I'll ask for completeness. Are you certain that you didn't get anything stuck in the motor mount, like plastic debris, or bits of leftover plastic skirt/brim? Are all the screws tight? Are the Z screw couplers tight and have you checked them for play?

I'd think that the most likely cuplrit would be a set screw that is allowing the motor to turn inside the coupler, or the coupler to turn without turning the screw. A very small amount would add up, particularly if you have fine-pitched screws. It's unlikely to be the control electronics, or the motor itself. I would think that a mechanical issue is the highest probability. (I just replaced my Z couplers, and had an issue where the threaded rod on one side would MOSTLY turn with the motor, buton high speed moves, or with sudden reversals like a short lift motion could get out of sync with the motor.)

I'd go over all of the screws, from motor mounts to couplers and make sure that they're tight. I'd go with both sides, just to be sure. Make sure that you can't turn the screws without the motors turning. With them powered on, you shouldn't be able to turn the screws at all.

@t3p3tony Sorry 'bout that. I "report to moderator" when I see one of those (But only once, even when there are 20.) On a forum this active, I'm probably not the only one, but the "I thought someone else would do it" factor applies, too. (I've been a forum moderator for other places before, I know how this sometimes works.)

Every once in a while the bots manage to sneak one past the mechanisms meant to keep them out. Sometimes the bot software gets better, sometimes they just get lucky. Whenever they do, it's always a fight like this. I'm almost certain that it's almost always SEO crap (Something like this one, where it seemed to be a website URL over and over again is almost certainly SEO.) and sometimes it's regular spam, trying to get users' attention.

Thanks for taking care if it!

You can specify a minimum of say -110mm and a maximum of 110mm (for example) in order to have the bed center be 0,0. Some people do this so that the same gcode will operate on multiple printers with different geometries or mechanisms.

I personally do not do this, since I use different materials and nozzle sizes, so I need to re-slice for different printers regardless.

In my case, I set it up so that 0,0 is the front right hand corner of the printable area, even though the printer mechanics can move the print head further. If memory serves, my minimums are -11mm X and -9mm Y. (Might be the other way around. My pause.g parks the print head at -5,-5.)

Thanks for the info.

I found the getting started docs, and missed that section. Go figure. Thanks for the link.

So I have ordered the mini 5 and the 1LC toolboard, as that seems like the best fit for the hardware that I have and plan to use. I have a Hemera hotend already, but if I'm going to mount the accellerometer to match X and Y axes, the mount will need to be different from what looks like it's intended. Also, I have the part cooling fan and Z probe already held in place using the front side mounts, so I'll add horizontal mounting on top.

I think the biggest thing that i'm looking forward to is the input shaping. All of my printers so far have suffered somewhat from ringing. I had a chance to play wiht a printer that had input shaping enabled and it was an eye opener for sure. The CANbus wiring also seems really nice to have, getting rid of that thick bundle of wires to the hotend will be a big relief.

Thanks again!

@droftarts Thanks.

The local reseller has the 1LC boards, I don't think they have the other. I'm not looking for blinding speed, the motors that I mean to use have a 2A max current, so the TMC2209 aren't a problem.

The idea of using the accelerometer for input shaping has appeal, too. I like RRF and am not looking to jump to klipper.

Also not sure what advantages adding a SBC like a Pi to the board offers, so look g forward to that.

Considering possible multi-material, would the +2 driver expansion still work with this? Well, for that I would still want to loom at CANbus connected options, most likely.

So I just want to triple check before ordering hardware.

New project, CoreXY printer with 3 Z motors.

Proposed control, Duet 3 Mini 5 + 1LC toolboard. If I understand correctly, the 1LC has an on board TMC2209 driver, so I should be able to use the 5 on-board drivers as alpha, beta, Z1, Z2, and Z3. Giving me 6 drivers in total. I think the 6HC is overkill as I don't want or need more than 1.5A current to any of the motors, and frankly the idea of the CANbus connected hotend is actually really appealing instead of running all of those wires to the Hemera.

If this won't give me the extra driver, I guess I need to get the extra 2 driver board.

Okay... This is still making me crazy...

Configuration is still as it was last. I've changed stuff and changed it back, and behaviour is as it was. When I power the printer up, the part fan (Fan 0) comes on, nothing that I can do powers it down, except to redefine it with thermostatic control. Then it will follow the heater, and still not turn on/off. I've been leaving it on, but trying some filaments that are a bit more picky about part cooling, and it isn't going well...

Doubtful. It's brand new, but with some of these Chinese parts that might not mean much. The fact that it worked reliably on thermostatic control is what really gets me though.

Hopefully I don't have to change the config file anymore, so if it acts up again, I'll replace the fan.

Okay. I give up. I left the printer on and had a shower, when I came back, the part fan was on, and I could turn it off. So... yay?

@Phaedrux that would be no.

So if I define fan 0 on out8, the fan comes on. If it's on out9, it is off. If I define it as thermostatic, it comes on at temperature, so pretty sure that it isn't hardware.

; Configuration file for Duet 3 MB 6HC (firmware version 3.3)
; executed by the firmware on start-up
;
; generated by RepRapFirmware Configuration Tool v3.3.15 on Tue Feb 21 2023 20:05:02 GMT-0800 (Pacific Standard Time)

; General preferences
G90                                          ; send absolute coordinates...
M83                                          ; ...but relative extruder moves
M550 P"DMG3D03"                              ; set printer name
M669 K1                                      ; select CoreXY mode

; Network
M552 P0.0.0.0 S1                             ; enable network and acquire dynamic address via DHCP
M586 P0 S1                                   ; enable HTTP
M586 P1 S0                                   ; disable FTP
M586 P2 S0                                   ; disable Telnet

; Drives
M569 P0.0 S0                                 ; physical drive 0.0 goes backwards
M569 P0.1 S0                                 ; physical drive 0.1 goes backwards
M569 P0.2 S1                                 ; physical drive 0.2 goes forwards
M569 P0.3 S1                                 ; physical drive 0.3 goes forwards
M569 P0.4 S1                                 ; physical drive 0.4 goes forwards
M569 P0.5 S1                                 ; physical drive 0.5 goes forwards
M584 X0.0 Y0.1 Z0.2:0.3:0.4 E0.5             ; set drive mapping
M350 X16 Y16 Z16 E16 I1                      ; configure microstepping with interpolation
M92 X100.00 Y100.00 Z100.00 E395.45          ; set steps per mm
M566 X900.00 Y900.00 Z60.00 E120.00          ; set maximum instantaneous speed changes (mm/min)
M203 X9000.00 Y9000.00 Z3000.00 E2700.00     ; set maximum speeds (mm/min)
M201 X3000.00 Y3000.00 Z1500.00 E3000.00     ; set accelerations (mm/s^2)
M906 X1100 Y1100 Z800 E800 I30               ; set motor currents (mA) and motor idle factor in per cent
M84 S60                                      ; Set idle timeout

; Axis Limits
M208 X-15 Y0 Z0 S1                           ; set axis minima
M208 X235 Y250 Z243 S0                       ; set axis maxima
M671 X-35.3:271.3:117.5 Y34.5:34.5:307.8 S5  ; Motor positions: -35.3,34.5; 271.3,34.5; 117.5,307.8

; Endstops
M574 X1 S1 P"^io0.in"                        ; configure switch-type (e.g. microswitch) endstop for low end on X via pin ^io0.in
M574 Y1 S1 P"^io1.in"                        ; configure switch-type (e.g. microswitch) endstop for low end on Y via pin ^io1.in
M574 Z2 S3                                   ; configure sensorless endstop for high end on Z

; Z-Probe
M950 S0 C"io4.out"                           ; create servo pin 0 for BLTouch
M558 P9 C"io4.in" H5 F120 T6000              ; set Z probe type to bltouch and the dive height + speeds
G31 P500 X0 Y-36 Z3.24                       ; set Z probe trigger value, offset and trigger height
M557 X5:205 Y2:202 S50                       ; define mesh grid

; Heaters
M308 S0 P"temp0" Y"thermistor" T100000 B4138 ; configure sensor 0 as thermistor on pin temp0
M950 H0 C"out0" T0                           ; create bed heater output on out0 and map it to sensor 0
M307 H0 B0 S1.00                             ; disable bang-bang mode for the bed heater and set PWM limit
M307 H0 R0.155 D15.47                        ; set PID parameters for heated bed
M140 H0                                      ; map heated bed to heater 0
M143 H0 S120                                 ; set temperature limit for heater 0 to 120C
M308 S1 P"temp1" Y"thermistor" T100000 B4138 ; configure sensor 1 as thermistor on pin temp1
M950 H1 C"out1" T1                           ; create nozzle heater output on out1 and map it to sensor 1
M307 H1 B0 S1.00                             ; disable bang-bang mode for heater  and set PWM limit
M307 H1 R1.800 K0.448:0.000 D7.97 E1.35 S1.00 B0 V24.1
M143 H1 S280                                 ; set temperature limit for heater 1 to 280C

; Fans
M950 F0 C"out9" Q500                         ; create fan 0 on pin out7 and set its frequency
M106 P0 S0 H-1                               ; set fan 0 value. Thermostatic control is turned off
M950 F1 C"out7" Q500                         ; create fan 1 on pin out8 and set its frequency
M106 P1 S0 H1 T45                            ; set fan 1 value. Thermostatic control is turned on
M950 F2 C"out4" Q500                         ; Pretend that the LED lighting is a fan...
M106 P2 S0 H0 T30:75                         ; set fan 2 value. Thermostatic control follows the bed
M950 F3 C"out8" Q500
M106 P3 S0 H1 T45

; Tools
M563 P0 D0 H1 S"Hemera"                      ; define tool 0
G10 P0 X0 Y0 Z0                              ; set tool 0 axis offsets
G10 P0 R0 S0                                 ; set initial tool 0 active and standby temperatures to 0C

; Custom settings are not defined

; Miscellaneous
T0                                           ; select first tool

Current state of config.g with fan 0 on out9 and a fan defined on out8 with thermostatic control. I also tried changing the tool to the non zero fan to see if that was it. Grasping at straws... currently the F parameter for M563 is not defined, to let it default to 0.

Okay... I changed the line:
M563 P0 S"Hemera" D0 H1 F1

So now it reads:
M563 P0 S"Hemera" D0 H1 F0

And... nothing changed. Still can't seem to control the fan, it still comes on full blast when the board powers up.

So... maybe it's the control pin? I changed it to "out9" and moved the fan connector. Yay, it's off... and won't turn on....

Okay, I'm re-reading the M563 page, and it seems that I should tell it that it's fan 0. I'll change that, and see how it works...

@dc42 M563? I guess I didn't touch that from the configuration tool, so I think it's defined as having fan 1 (Which is the thermostatic controlled fan that keeps the heat from coming up the throat.)

config.g:

; Configuration file for Duet 3 MB 6HC (firmware version 3.3)
; executed by the firmware on start-up
;
; generated by RepRapFirmware Configuration Tool v3.3.15 on Tue Feb 21 2023 20:05:02 GMT-0800 (Pacific Standard Time)

; General preferences
G90                                          ; send absolute coordinates...
M83                                          ; ...but relative extruder moves
M550 P"DMG3D03"                              ; set printer name
M669 K1                                      ; select CoreXY mode

; Network
M552 P0.0.0.0 S1                             ; enable network and acquire dynamic address via DHCP
M586 P0 S1                                   ; enable HTTP
M586 P1 S0                                   ; disable FTP
M586 P2 S0                                   ; disable Telnet

; Drives
M569 P0.0 S0                                 ; physical drive 0.0 goes backwards
M569 P0.1 S0                                 ; physical drive 0.1 goes backwards
M569 P0.2 S1                                 ; physical drive 0.2 goes forwards
M569 P0.3 S1                                 ; physical drive 0.3 goes forwards
M569 P0.4 S1                                 ; physical drive 0.4 goes forwards
M569 P0.5 S1                                 ; physical drive 0.5 goes forwards
M584 X0.0 Y0.1 Z0.2:0.3:0.4 E0.5             ; set drive mapping
M350 X16 Y16 Z16 E16 I1                      ; configure microstepping with interpolation
M92 X100.00 Y100.00 Z100.00 E395.45          ; set steps per mm
M566 X900.00 Y900.00 Z60.00 E120.00          ; set maximum instantaneous speed changes (mm/min)
M203 X9000.00 Y9000.00 Z3000.00 E2700.00     ; set maximum speeds (mm/min)
M201 X3000.00 Y3000.00 Z1500.00 E3000.00     ; set accelerations (mm/s^2)
M906 X1100 Y1100 Z800 E800 I30               ; set motor currents (mA) and motor idle factor in per cent
M84 S60                                      ; Set idle timeout

; Axis Limits
M208 X-15 Y0 Z0 S1                           ; set axis minima
M208 X235 Y250 Z243 S0                       ; set axis maxima
M671 X-35.3:271.3:117.5 Y34.5:34.5:307.8 S5  ; Motor positions: -35.3,34.5; 271.3,34.5; 117.5,307.8

; Endstops
M574 X1 S1 P"^io0.in"                        ; configure switch-type (e.g. microswitch) endstop for low end on X via pin ^io0.in
M574 Y1 S1 P"^io1.in"                        ; configure switch-type (e.g. microswitch) endstop for low end on Y via pin ^io1.in
M574 Z2 S3                                   ; configure sensorless endstop for high end on Z

; Z-Probe
M950 S0 C"io4.out"                           ; create servo pin 0 for BLTouch
M558 P9 C"io4.in" H5 F120 T6000              ; set Z probe type to bltouch and the dive height + speeds
G31 P500 X0 Y-36 Z3.24                       ; set Z probe trigger value, offset and trigger height
M557 X5:205 Y2:202 S50                       ; define mesh grid

; Heaters
M308 S0 P"temp0" Y"thermistor" T100000 B4138 ; configure sensor 0 as thermistor on pin temp0
M950 H0 C"out0" T0                           ; create bed heater output on out0 and map it to sensor 0
M307 H0 B0 S1.00                             ; disable bang-bang mode for the bed heater and set PWM limit
M307 H0 R0.155 D15.47                        ; set PID parameters for heated bed
M140 H0                                      ; map heated bed to heater 0
M143 H0 S120                                 ; set temperature limit for heater 0 to 120C
M308 S1 P"temp1" Y"thermistor" T100000 B4138 ; configure sensor 1 as thermistor on pin temp1
M950 H1 C"out1" T1                           ; create nozzle heater output on out1 and map it to sensor 1
M307 H1 B0 S1.00                             ; disable bang-bang mode for heater  and set PWM limit
M307 H1 R1.800 K0.448:0.000 D7.97 E1.35 S1.00 B0 V24.1
M143 H1 S280                                 ; set temperature limit for heater 1 to 280C

; Fans
M950 F0 C"out8" Q500                         ; create fan 0 on pin out7 and set its frequency
M106 P0 S0 H-1                               ; set fan 0 value. Thermostatic control is turned off
M950 F1 C"out7" Q500                         ; create fan 1 on pin out8 and set its frequency
M106 P1 S0 H1 T45                            ; set fan 1 value. Thermostatic control is turned on
M950 F2 C"out4" Q500                         ; Pretend that the LED lighting is a fan...
M106 P2 S0 H0 T30:75                         ; set fan 2 value. Thermostatic control follows the bed

; Tools
M563 P0 S"Hemera" D0 H1 F1                   ; define tool 0
G10 P0 X0 Y0 Z0                              ; set tool 0 axis offsets
G10 P0 R0 S0                                 ; set initial tool 0 active and standby temperatures to 0C

; Custom settings are not defined

; Miscellaneous
T0                                           ; select first tool