Heating Chamber for a 3d printer!
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ok after weeks of bouncing about i am still having issues with the autotune pid bb what have you and the results of the set point are over shot and no not settle back down 5c over and it is still calling on the ssr when its in over the set point even after waiting for it to settle it never does
the heaters in the chamber are 6A@120vac switched by 3-32 vdc control side
during the on off sequence the out for the heater and the green light and red on the duet out put are on and off in different brightness's from the leds like its pid varying the out put amps or volts even in bang bang mode from pid and this ssr is 15mA 3-32vdc on the control side
the results are under the second M307 from the auto tune wich took 2.25 hrs and was accurate tru the cycles meaning it did the same thing heat and cool the same each time accurately not sure why this auto tune is so bad it is a oem chamber and only run from a thermocouple and an SSRit needs to shut off 2c before the set point due to the thermal mass and not switch 15-25 times a min, i need it to switch 3-5 times a min is acceptable for a chamber on BB
if someone has any suggestions or answers i could use some help getting a real chamber to work with duet
for some reason it is rocket science
i would also try a pid from a food dehydrator or space heater they are so close to each other is terms of controlling the switching and how they do is a simple profile just not simple for duet on a OEM chamberoozebot helped with 1 M307 line but keeps alarming out as the heats dont climb fast enough for the duet so it sais not reacing 2.2c/sec ALARM
its a chamber it gonna take a few
are there other tuning algorithms for the duet or a setting that may help with keeping a set point?
config.g
; Configuration file for Duet 3 (firmware version 3.3)
; executed by the firmware on start-up
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; generated by RepRapFirmware Configuration Tool v3.3.10 on Sun Jun 19 2022 17:18:42 GMT-0400 (Eastern Daylight Saving Time); General preferences
G90 ; send absolute coordinates...
M83 ; ...but relative extruder moves
M550 P"xxxxxxxx" ; set printer name; Network
;M552 ; 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 P0.1 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 P0.0 S1 ; physical drive 0.0 goes forwards
M584 X0.1 Y0.2 Z0.3 E0.0 ; set drive mapping
M350 X16 Y16 Z16 E16 I1 ; configure microstepping with interpolationM92 X134.0 Y133.3 Z1420.0 E410.00 ; set steps per mm
M566 X900.00 Y900.00 Z60.00 E120.00 ; set maximum instantaneous speed changes (mm/min)
M203 X6000.00 Y6000.00 Z180.00 E1200.00 ; set maximum speeds (mm/min)
M201 X500.00 Y500.00 Z20.00 E250.00 ; set accelerations (mm/s^2)
M906 X1600 Y1600 Z1600 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 X246 Y210 Z300 S0 ; set axis maxima; Endstops
M574 X2 S1 P"^io1.in" ; configure switch-type (e.g. microswitch) endstop for high end on X via pin ^io1.in
M574 Y2 S1 P"^io2.in" ; configure switch-type (e.g. microswitch) endstop for high end on Y via pin ^io2.in
M574 Z1 S2 ; configure Z-probe endstop for low end on Z; Z-Probe
M558 P0 C"^io7.in" H5 F120 T6000 ; set Z probe type to switch and the dive height + speeds
M558 H30 ;*** Remove this line after delta calibration has been done and new delta parameters have been saved
;DO NOT TOUCH THIS VALUE vvvvv
G31 P500 X45 Y120 Z2.672 ; set Z probe trigger value, offset and trigger height
;M557 X25:200 Y25:235 P4 ; define mesh gridM308 S5 P"spi.cs0" Y"thermocouple-max31856" T"J" A"Core temperature"
; Heaters
; Chamber
M308 S0 P"spi.cs1" Y"thermocouple-max31856" T"K" A"Chamber"
M950 H0 C"out2" T0 ; create chamber heater output on out2 and map it to sensor 0
M307 H0 B1 S1.00 E1.35 D159.98 K0.048:0.000 R0.027 ; disable bang-bang mode for the chamber heater and set PWM limit (B1 is Bang Bang B0 is PID)
;M307 H0 B1 C7200 D50 R0.01 ; oozebot helped with this trial
;M307 H0 R0.027 K0.048:0.000 D159.98 E1.35 S1.00 B0 auto tune copy chamber
M141 H0 ; map chamber to heater 0
M143 H0 S150 ; set temperature limit for heater 0 to 150C
M570 H0 P3600 T50 S0 ; H0 (heat 0) P3600 (timeout in seconds before alerting) T50 (deviation from setpoint in C) S0 (timeout in minutes before canceling); Hot End
M308 S1 P"temp3" Y"pt1000" A"Hot End" ; configure sensor 1 as PT1000 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
M143 H1 S280 ; set temperature limit for heater 1 to 280C; Fans
M950 F0 C"out4" Q500 A"5015" ; 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"out8" Q500 A"Stratasys" ; create fan 1 on pin out8 and set its frequency
M106 P1 S0 H-1 ; set fan 1 value. Thermostatic control is turned off; Tools
M563 P0 D0 H1 F5:6 ; 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
M501 ; load saved parameters from non-volatile memory
T0 ; select first tool
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Does anyone have a mains powered chamber with a thermocouple/thermistor in the actual chamber that could share their config with me?
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110 eyes no clues .................................anyone??
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must be the tuning algorithm......... or SOP's...lol
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Do i need an M141 for a chamber and does it change the heating rhythm??
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add Q parameter to m950 to lower the pwm freq .
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@hackinistrator its switching an SSR the HZ dont matter no...? as long as it within the spec of the SSR 3-32vdc 15mA control side
the switching side is mains power 6A 120 VAC (on or off) no ramping capability except pwm from the control side no?
if it means the frequency of switching i am in...but it says HZ hertz frequency usually 60 hz as is 120vac it is at 60 hz mains power which would not be adjustable without a VFD and/or winding's before it's heateror maybe i am not understanding how this could benefit me other ways maybe algorithms at low HZ switch differently??
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@rexx it has nothing to do with mains freq . its the pwm switching freq .
heated beds and chamber heaters that are powered by mains usually use low switching freq , around 10hz .
also it will able you to see what's actually going on (led lights on when out on) .
i don't know what type of ssr you are using , some of them can't work at high freq , and some can . default freq is 250hz if you don't use the q parameter . -
@rexx said in Heating Chamber for a 3d printer!:
or maybe i am not understanding how this could benefit me other ways maybe algorithms at low HZ switch differently??
Zero crossing SSR turns power on/off just when the mains voltage crosses zero level, and for a good reason, and that happens only 120 times a second. If you try to control it with 250hz PWM, it needs to turn turn power on/off 500 times a second which it can't do. Hence the use of 10Hz PWM which is low enough and provide some proportionality of duty cycle to power.
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@zapta this is absolutely great thank you
what would my M307 look like with a chamber thats slow but keeps temps and is insulated well, what you would try first ?
is this only put in config.g correct?is it 0.1 i am going to try it at 10 hz is 20 times a second still not to much?? i will try it!
Cheers
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@zapta i tried S0.10 in M307 but seen that M950 is now where Q is used to set HZ so i am trying M950 Q50 M307 S1.00
S0.01 did light the ssr up but is not on,not heat at this but only faint dim leds on the out and ssr so i will try Q50 in the M950 and see tuning....
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@rexx as the other have said, you'll want to use a lower pwm frequency to control the SSR, like Q5 or Q10. Q50 may not work for the reasons explained by @zapta
Home-built CoreXY, Duet Wifi, Chimera direct drive, 2x BMG, 300x300x300 build volume
i3 clone with a bunch of mods -
@engikeneer thank you i have stopped the tuning and have set the pwm to Q5 in the M950 and restarted the tune once back to ambient temperature again
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@engikeneer what is a reasonable time to autotune i am at phase 3 but has been for 3.15 hrs and counting for a total of 4.5 hrs
when i send M303 it sais i am on 4 of 4 measuring but did not say it started to like 1,2,3 until i sent M303...
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@rexx can be several hours especially for large slow heaters with long cooldown times like a chamber. By default it does 25 heating cycles to determine behaviour.
Your 2deg cycle may also cause it some confusion if there is some variation I'm ambient temperature during tuning -
ok much playing with but i got it Q ended up to be Q1.25 and the switching is just like the oem original now and only +/-.5c spread the R was set to R0.030 which auto tune suggested R0.027 was close but the D was suggested to D159 by auto tune and D28 worked best for me
thank you to all whom guided me here the D,R and Q was the issues i was having and is a ok now!
