@jay_s_uk ah, no. Those are values generated by RRF configurator, will adjust those values.

That was my mistake, Q1 is what was missing in both cases.

@hamel The problem is time, this machine is used to make parts that are then used to make molds for fiberglass parts. A custom replacement wouldn't be here till May.... I already checked. Four smaller ones can be here by Monday. Ultimately its not my decision to make, bosses liked the faster option.

@jens55 @o_lampe

Update, after talking to my boss, I'm switching the plan. We instead are going to go with four 1000W heaters, run them in two parallels with two separate 120V sources, and 2 SSRs with the same signal wire. That way the current draw wont be too much for the current breakers, and each of the heaters will get 120V.

@Phaedrux Both are the newest firmware, I had to update the paneldue just to get it to show two beds on the screen.

Hello all,

I have my bed heaters split in zones. I am using heater 0 (bedheat) for one zone, then heater 3 (E1) for the second zone. On the web control I can assign temp to both like I would expect, however when I try to do the same on the paneldue it assigns the temp that I select to heater 3 to heater 0.

here is my config.g

; Configuration file for Duet WiFi (firmware version 3)
; executed by the firmware on start-up
;
; generated by RepRapFirmware Configuration Tool v3.2.2 on Fri Jan 22 2021 11:13:01 GMT-0600 (Central Standard Time)

; General preferences
G90                                                ; send absolute coordinates...
M83                                                ; ...but relative extruder moves
M550 P"Caymas 3D Printer"                          ; set printer name

; Network
M552 S1                                            ; enable network
M586 P0 S1                                         ; enable HTTP
M586 P1 S0                                         ; disable FTP
M586 P2 S0                                         ; disable Telnet
 
; Drives
M569 P8 R1 T2.5:2.5:5:5 S0                         ; physical drive 8 goes forwards
M569 P6 R1 T2.5:2.5:5:5 S1                         ; physical drive 6 goes forwards
M569 P2 S0                                         ; physical drive 2 goes forwards
M569 P5 R1 T2.5:2.5:5:5 S0                         ; physical drive 5 goes forwards
M569 P3 S0 										   ; physical drive 3 goes forwards 
M584 X6 Y8 Z2:3 E5                                 ; set drive mapping
M671 X-10.0:1200.0 Y450.5:450.5	S3				   ; Set z motor relative locations 
M350 X16 Y16 Z16 E16 I1                            ; configure microstepping with interpolation
M92 X320 Y320 Z640 E80                    ; set steps per mm
M566 X200.00 Y200.00 Z12.00 E120.00                ; set maximum instantaneous speed changes (mm/min)
M203 X3000.00 Y3000.00 Z340.00 E4000.00            ; set maximum speeds (mm/min)
M201 X200.00 Y200.00 Z20.00 E250.00                ; set accelerations (mm/s^2)
M906 X2000 Y2000 Z2800 E800 I30                    ; set motor currents (mA) and motor idle factor in per cent
M84 S30                                            ; Set idle timeout

; Axis Limits
M208 X0 Y0 Z0 S1                                   ; set axis minima
M208 X1170 Y1100 Z1100 S0                          ; set axis maxima

; Endstops
M574 X1 S1 P"!xstop"                                ; configure active-low endstop for low end on X via pin xstop
M574 Y1 S1 P"!ystop"                                ; configure active-low endstop for low end on Y via pin ystop
M574 Z1 S2                                         ; configure Z-probe endstop for low end on Z

; Z-Probe
M558 P1 C"zprobe.in+zprobe.mod" H5 F240 T3600      ; set Z probe type to unmodulated and the dive height + speeds
G31 P500 X0 Y-69.85 Z1.55 	                    ; set Z probe trigger value, offset and trigger height
M557 X100:1170 Y100:1100 S100                      ; define mesh grid

; Heaters
M308 S0 P"bedtemp" Y"thermistor" T50000 B3950      ; configure sensor 0 as thermocouple on pin bedtemp
M950 H0 C"bedheat" T0                              ; create bed heater output on bedheat and map it to sensor 0
M307 H0 B0 S1.00    							   ; disable bang-bang mode for the bed heater and set PWM limit
M140 H0                                            ; map heated bed to heater 0
M303 H0 S60											;Tune for 60C
M307 H0 R0.168 C358.6 D5.019 S1.00 V24.2
M143 H0 S120                                       ; set temperature limit for heater 0 to 120C
M308 S1 P"spi.cs2" Y"thermocouple-max31856"        ; configure sensor 1 as thermistor on pin e0temp
M950 H1 C"e0heat" T1                               ; create nozzle heater output on e0heat and map it to sensor 1
M307 H1 B0 S1.00                                   ; disable bang-bang mode for heater  and set PWM limit
M303 H1 S200										;Tune for 200c
 M307 H1 R2.211 C192.4 D8.94 S1.00 V24.2
M143 H1 S320                                       ; set temperature limit for heater 1 to 320C
M308 S2 P"e1temp" Y"thermistor" T50000 B3950  		; configure sensor 2 as thermistor on pin e1temp
M950 H2 C"e1heat" T2                          		; create bed heater output on e1heat and map it to sensor 2
M307 H2 B0 S1.00                               		; disable bang-bang mode for the bed heater and set PWM limit
M140 P1 H2                                        	; map chamber to heater 2
M143 H2 S120    									; set temperature limit for heater 2 to 120C
M307 H0 R0.168 C358.6 D5.019 S1.00 V24.2


; Fans
M950 F0 C"fan0" Q500                               ; create fan 0 on pin fan0 and set its frequency
M106 P0 S0 H-1                                     ; set fan 0 value. Thermostatic control is turned off
M950 F1 C"fan1" Q500                               ; create fan 1 on pin fan1 and set its frequency
M106 P1 S1 H1 T45                                  ; set fan 1 value. Thermostatic control is turned on

; Tools
M563 P0 D0 H1 F0                                   ; 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
M575 P1 S1 B57600                                  ; enable support for PanelDue
M911 S10 R11 P"M913 X0 Y0 G91 M83 G1 Z3 E-5 F1000" ; set voltage thresholds and actions to run on power loss

M501

Thanks,
T-

@alankilian Alright so say I wanted to split the signal, and make the the pairs of heaters work separate, so one SSR with two heaters and two thermistors wired in parallel. That way the build plate has two zones, then there is less error between the heaters. how do I wire the signal for the second pair of heaters, run off of another tool? The first one is controlled by the bedheat output on the board, I only use one extruder heater on E0, so do I control the second half of the bed with E1 then assign it in config.g?

The heaters are two pairs in parallel controlled by two SSRs getting a single signal, end goal is to put a single sensor in the center of the bed, but waiting on parts for that. The reason for not having each heater individually controlled is these four are replacing a single custom 1000X1000mm mat. I had to split the single power source and SSR into two because of amperage draw. I get that I could control them individually however, because of the size of parts that are printed on it there isn't a need. This is a printer at my work that I did not build, and time is a factor on getting it running again. Then end goal is to put a single thermistor in the center of the bed and have that be the temp reading, however Time.

@Phaedrux That's the plan long term, however in the meantime (waiting on parts that are on backorder) I was going to use the built in ones as a stopgap to be able to print until then.

Hello all,

I am building a multi heater print bed because of size. I've got the wiring I need, and there are four NTC 100K 3950 (one in each heater) wired in parallel. I know that I will need to reduce the T value, but I have also seen that for the 3950 I will need to put in specific heat parameters in the RRF config tool.

Any suggestions would be greatly appreciated.

Thanks,
-T

Okay just to make sure, it doesn't hurt to ask. The temp sensors on the heaters are NTC 100K 3950 thermistors. From what I have seen/been told I should wire them in parallel so it reads the highest temp coming from all four, and I will have to reduce the T parameter because the resistance will be lower. Is there anything else I should keep in mind?

@jens55 They are 20 amp breakers, one parallel pair of the 1000W heaters will draw a max of 16.6666667A. Found another person who made a similar bed size with the same heaters, he had run into the same issue I was having with too big heaters, and had to go to this size.

@jens55 @o_lampe

Update, after talking to my boss, I'm switching the plan. We instead are going to go with four 1000W heaters, run them in two parallels with two separate 120V sources, and 2 SSRs with the same signal wire. That way the current draw wont be too much for the current breakers, and each of the heaters will get 120V.

@jens55 From what I can find the previous bed mat was a 220v 2000w, being run off of 120v, so 1000W. I can't be 100% sure because there are no markings on it.

I have been seeing that generally, 0.6W/cm^2 is the ideal when calculating what you need, so if y bed is 110cm^2 1300 should be plenty? let me know what you think.

Thanks!
T-