Posts made by dcaron

Hi David,
Is using the HW floating point beneficial to specific performance aspects at this point? Also, is this release including all of alpha 7 enhancements?

Dyze have a PT100 available, however it's not advertised. I still got one at the very beginning they were hesitant to sell because the PT100 insulation wasn't up to their spec limiting the temperature under 380°C. I don't use it that high anyway. I can say it works like a charm, the Duet, PT100 and Dyzend really is a winning combination.

I highly encourage anone printing materials at 350°C and under to get the PT100 and the daughterbaord. Just ask Dyze design directly, they are very helpful.

Temperature overshooting is likely since the hotend has a big heater. On 24v I used 20% power to tune. On 12v, don't go over 50% PWM.

@mb0:

any progress on this? i have a dyzend too and have trouble getting it running on 1.17dev6

I tested the 1.17dev6. It works, however the thermistor still has so much resistance at room temp that the reported temperature is still off and fluctuating. Moreover, the auto range ADC calibration means it sometimes initializes at 2-10°C at room temp or 15-30°C randomly. The room temperature fluctuation mens RRF forbids auto calibration. Dyze Design has a PT100 coming out very soon. I got it early and works well with the pt100 daughterboard. Now things work flawlessly.

@dc42:

I have just committed RRF version 1.17-dev1 on github. It includes changes to better support the Dyze thermistor, although I don't yet have one for testing with. See https://github.com/dc42/RepRapFirmware/blob/dev/WHATS_NEW for more details. Caution: I do minimal testing on dev builds.

Thank you David.
I will test the 1.17 dev tonight and report results with my Dyze 500°C thermistor.

I have a 12v PCB heatbed. If I fed it 24v directly it would run at about 15-16 amps. From a hardware perspective, would the board be able to sustain this load if I limited the pwm to 66% giving me an average 10A or is the peak current too high? I don't want to get a 24v pcb bed because they often have too high resistance values limiting the power output to measly 100-125w. I should probably invest in a silicone AC heat pad, but I don't seem to find reasonably priced SSR that can be trusted. Had a bad experience with ebay ones…

Thanks for your advice.

JasonW,
From your information: 0.3 A Z motors, I assume you have very high resistance and impedance motors. If this is the case, i.e. 12v rated motors, you will have very poor performance from them, especially in series. I see you have T8X2 leadscrews, and 1600 steps per mm on this setup. To move at 300 mm/min, the steppers, your motors would have to turn at 2.5 rps. Your motors will already have almost no torque when wired in series at this speed assuming these are high impedance motors. As an example, I have 30 Ohm resistance, and 37mH impedance motors on my machine. They don't run well without 24v power. I will swap them as soon as I can. You could probably use a Y cable fotr the Z motors and use jumpers in the second header to have them run in parallel like on ramps (adjust amperage accordingly). Could a hardware designer commnet on this?

Also, be careful if you run a 0.3 A motor at 1.8 A, they would probably become burning hot if kept energized.

Thanks dc42,
I've been told Dyze Design is working on a low thermal mass PT100 for their hotend. According to them, this should be available shortly. I will probably grab one if the price is reasonable. I already have the PT100 daughterboard ready! I agree the PT100 has desirable linear characteristics for wide range temperature measurements. The problem with thermistors is that they have to be specified for a narrower temperature range to be precise. The reasoning for the Dyze thermistor is still quite interesting regarding the precision and low response time around printing temperature. The only real flaw is the very low accuracy/high resistance at room temperature.
I'm not affiliated with them whatsoever, but it's still a very good hotend with a lot of desirable characteristics.

I will chime in on this issue. I own a Dyze 500°C thermistor. Without a parallel resistor it gives me the disconnected fault. The real resistance at 25°C is really around 4.5MOhm and much higher at 20°C. The board works with a parallel 1 MOhm resistor. I actually made a wiring extension with parallel Dupont connector to be able to experiment with different resistors. it's not perfect, but the measurement error gets very small at 200-250°C which is my preferred printing temperature. If we had support for steinhart-hart parameters (on FW 1.17) I could probably make it read room temperature accurately, but right now, I have to live with 45-50°C readings at 20°C (from the parallel resistance error).

I really wish there would be a firmware workaround to disregard the "disconnected" state for these thermistors at room temp.

I fountd the culprit: the right formulation was S0 to end the calibration routine. I changed my file to the form in the Wiki:

M561 ; clear any existing bed transform
G30 P0 X10 Y10 Z-99999 ; define 4 points in a clockwise direction around the bed, starting near (0,0)
G30 P1 X10 Y190 Z-99999
G30 P2 X190 Y190 Z-99999
G30 P3 X190 Y10 Z-99999
G30 P4 X100 Y100 Z-99999 S0 ; finally probe bed centre, and calculate compensation
G1 X0 Y0 F5000 ; move the head to the corner (optional)

Peridot,
I did add 4 after the S parameter, it still doesn't work. It seems to hang on the next move (10 mm z lift). It beeps just after the 1500 ms delay. It seems like a stepper beep and then it hangs. It doesn't accept new commands or report temperatures. The web interface is still functional and a software reset brings it back to normal.

It started just today, I'm running 1.16 beta 10 and the steppers seem to emit a loud beep once I send any command after G32 completes. The controls are then unresponsive until I reset the board. Could it be a mathematical error following the bed correction matrix? G30 by itself runs fine. The problem seems to be tied to G32 only. I can only see one thing I changed today, and that would be the z probe offset. I actually set it to 1.89, does it support this format?

Any advice?
Here are my config.g and bed.g

CONFIG.G;
; FT 2020 i3 config file for dc42 Duet firmware

; Prologue and comms section
M111 S0 ; Debug off
;*** ;*** Wifi Networking
M552 S1 ; Enable WiFi

M555 P2 ; Set output to look like Marlin
M575 P1 B57600 S1 ; Comms parameters for PanelDue

; Movement section
M569 P0 S1 ; Drive 0 goes forwards (change to S0 to reverse it)
M569 P1 S1 ; Drive 1 goes forwards
M569 P2 S1 ; Drive 2 goes forwards
M569 P3 S1 ; Drive 3 goes forwards
M569 P4 S1 ; Drive 4 goes forwards
M574 X1 Y1 Z0 S0 ; set endstop configuration (X, Y and Z endstops, at low end, active high)
M906 X1360 Y1360 Z300 E300 ; Set motor currents (mA)
M201 X1000 Y1000 Z15 E1000 ; Accelerations (mm/s^2)
M203 X15000 Y15000 Z250 E3600 ; Maximum speeds (mm/min)
M566 X1200 Y1200 Z30 E60 ; Minimum speeds mm/minute
M208 X200 Y200 Z140 ; set axis maxima (adjust to suit your machine)
M208 X0 Y0 Z0 S1 ; set axis minimum (adjust to make X=0 and Y=0 the edge of the bed)
M350 X32 Y32 Z16 E32 I0 ; Set 16x microstepping without interpolation
;M350 X16 Y16 Z16 E16 I1 ; Set 16x microstepping with interpolation
M92 X320 Y320 Z1600 ; Set axis steps/mm
;M92 X160 Y160 Z1600 ; Set axis steps/mm
M92 E185.2:185.2 ; Set extruder steps per mm
G21 ; Work in millimetres
G90 ; Send absolute coordinates…
M83 ; ...but relative extruder moves

; Z probe section
;M558 P0 ; No Z probe
;G31 X-11.0 Y0 Z1 P500 ; Set the probe height and threshold (put your own values here)
M558 P1 X0 Y0 Z1 H6 F150 T3000 ; smart IR Z probe, used for homing Z axis only, dive height 3mm, probe speed 200mm/min, travel speed 5000mm/min
G31 P500 X0 Y0 Z1.89 ; set threshold and offsets

; Heater and thermistor section
;*** If you have a Duet board with 1K thermistor series resistors, change R4700 to R1000 to the following M305 commands
M305 P0 T100000 B4036 R4700 H0 L0 ; Put your own H and/or L values here to set the bed thermistor ADC correction
M305 P1 T6858834 B5425 R4700 H0 L0 ; Put your own H and/or L values here to set the first nozzle thermistor ADC correction
;M305 P1 T6808015 B5422 R4700 H-10 L0
;M305 P2 R4700 H0 L0 ; Put your own H and/or L values here to set the second nozzle thermistor ADC correction
M301 H1 P22.0 I0.2 D180 T0.2 S1 W180 B30 ; NEW PID settings extruder 0
M307 H0 A 387.9 C304.5 D6.5 B0 S0.8 ;Heater 0 model: gain 387.9, time constant 304.5, dead time 6.5, max PWM 0.80, in use: yes, mode: PID
Heater 0 model: gain 387.9, time constant 304.5, dead time 6.5, max PWM 0.80, in use: yes, mode: PID

;M301 H1 P9.5 I0.75 D30.15 T0.50 S1.0 ; OLD PID settings for extruder 0
;M301 H2 P10 I0.10 D100 T0.50 S1.0 ; PID settings for extruder 1
M570 H1 P30 T30 S120 ; Increase to allow extra heating time if needed
M143 S493 ; Set max hot end temp 493°C

; Tool definition section
M563 P0 D0 H1 ; Define tool 0 to use extruder drive 0 and heater 1
G10 P0 S0 R0 ; Set tool 0 operating and standby temperatures
;*** If you have a dual-nozzle build, un-comment the following 2 lines
;M563 P1 D1 H2 ; Define tool 1
;G10 P1 S0 R0 ; Set tool 1 operating and standby temperatures

; Bed probe section (not needed if you use a bed.g file)
;*** Adjust the XY coordinates in the following M557 commands to suit your build and the position of your Z probe
;M557 P0 X40 Y40 ; Four...
;M557 P1 X160 Y40 ; ...for bed...
;M557 P2 X160 Y160 ; ...probe points...
;M557 P3 X40 Y160 ; ...levelling
;M557 P4 X121 Y100 ; 5th probe point for levelling (un-comment this to get a 5th point at the centre of the bed)

; Epilogue
;*** If you are using axis compensation, put the figures in the following command
M556 S78 X0 Y0 Z0 ; Axis compensation here
; select first hot end

; macro /sys/bed.g Auto calibration routine for a Cartesian printer: 1 to 5 probe points
M561 ; clear any bed transform, otherwise homing may be at the wrong height
G1 Z6 F200
G1 X40 Y40 F2000 ; move head
G30 P0 Z-100000 ; probe
G1 Z5 F200 ; rise head
G1 X160 Y40 F2000
G30 P1 Z-100000
G1 Z5 F200
G1 X160 Y160 F2000
G30 P2 Z-100000
G1 Z5 F200
G1 X40 Y160 F2000
G30 P3 S Z-100000 ; probe and calibrate with 4 parameters (as there is 4 points)
G4 P1500 ;Leave the probe there to give the web interface time to report the plane points
G1 Z10 F200

T3P3Tony,
Are the IR probes the new version with the optimized 1.2 firmware?

@dc42:

dcaron, have you looked in the Console page of DuetWebControl or PanelDue to see the cause of the heater fault?

If you still get heater faults with the heater off, then it must be registering a disconnected thermistor. A possible workaround is to connect a resistor of several hundred Kohms in parallel with the thermistor. This will increase the reading at low temperatures.

After you select a higher setpoint temperature, there is no check on heating rate until twice the heater dead time has expired. So this should get you to 60C without faulting.

Another possibility is to use a thermocouple or PT100 instead of the thermistor. These devices cover a wide temperature range without sacrificing resolution at the ends.

HTH David

Thanks for all your answers.

I did install a parallel resistance and now it's registering a temperature which is obviously off. I don't mind at the moment and I should get the right setting by trial and error.
I do agree it will be better with a pt100 or thermocouple. I now realize I should have gotten the pt100 daughter board with my preorder along with a mini IR probe. Unfortunately, the themocouple connection on a Dyzend is threaded (which is good) but is not compatible with other standard pt100. They do have an adapter for an Ultimaker style pt100. I don't know where I could get a compatible rtd at a decent cost.

Now to get printing…

dc42, thanks for the reply. I just did some quick calculations. Since the resistance is so high at room temp (4500+ kOhm) it would probably appear to be read an input of 3.297 vdc which is 99,9+% of the full ADC value. If i added a 500 kOhm resitor in parallel. What would be the magic number value of the resistor to make sure I don't get a disconnected thermistor at romm temp? Probably a 680 kOhm would work fine, it would get in the 3.27 vdc range. Am I doing the calculations right?

Regards,
David

I use Dyze design thermistor (500°C) which we discussed some time ago. It gives heater errors even when idel and the nozzle inactive. Yes, the input is noisy, it has very low resolution at room temp so it jumps up and down 5+°C. I was previously using heater fault inhibition in Marlin for a couple of seconds when heating. By 60°C, it gets smooth enough to read noise free, so the inhibition was not adding significant risk. Right now the board is unusable for me since I cannot even get it to stay at room temp without going in fault. Would there be a wayof inhibiting the check when heater peower is zero an then waiting a couple of seconds on heatup?

Thanks in advance,

Regards,

I don't own a DyzeXtruder, but I do own a Dyzend hotend. I must say It's fantastic. Performance of their thermistor has been great except for room temperature which is easily corrected by adding a slight inhibition delay for the "disconnected thermistor" function in Marlin. I really hope to make it functional on the Duet Wifi. The hotend comes with hard precision machined nozzle which has given me excellent prints so far.