Posts made by llamazen

Back to the original topic. I finally found some time to play with the printer again and tried your suggestions.

I have forced the steps per mm to 64 and did a test print. It did not fix the problem but the extruder motor was louder.

I have printed 2 hollow test-cubes next to each other. There were no signs of under extrusion but the retraction cylinders looked bad.

Finally I have decided to just use the extra prime amount for the time being. It gives me the good results inspite of my reluctance to use it.

Thank you for your input. I learned a lot about the finer details of extruders.

@deckingman OK got it. I'll do a print with 64 and 256.

Thanks guys for the input.

@deckingman @Phaedrux Sorry guys, I don't quite understand what you're saying. I currently set the microstepping of the extruder to 16 interpolated.

As far as I know, this sets the microstepping 256 virtual steps. I have tried setting removing interpolation but the motor gets noisy and whiny like it did with the cheap drivers.

I did a test print today with 0.075mm^3 extra prime after retraction and it printed OK.

It's weird though because I never had to use it before. I got the number from the E3D nozzle diagram for my 0.4mm nozzle.

@phaedrux Here it is.

AI3M_03_RetractionCalibration.gcode

@bot it's 407 steps/mm. You are saying that the g-code asks for so little filament that the motor doesn't even move?

If yes, then I think that's not the case. The motor visibly spins and at 45mm/s retraction speed it sounds like a zipper when you close it very fast. I lowered the retraction speed to 20mm/s because it got annoying.

@doctrucker I will test that. So I'll print 2 hollow cubes next to each other and label the respective walls on each cube (i.e. left wall on cube 1 with left wall on cube 2 will be labeled "A" for example).

Then after I print them at the same time, i measure the thickness of the wall A on cube "1" and the wall A on cube "2". The thicknesses should be within acceptable limits. Do I understand that correctly?

I normaly do 2-layer walls for the hollow cube test. Should I try a 1-layer wall as well?

@doctrucker Extrusion thickness is set at 0.4mm. I did a 2-wall hollow cube and measured the wall thickness. It's 0.79-0.80mm, so close enough.

Since yesterday, I've been messing with "extra prime amount" and I got one good print. I'm printing something else now to see if it does the trick.

Thanks for your input.

Hello gentlepeople!

I'm having a hard time understanding this issue. I wanted to print something at 0.1mm layer height and noticed that some layers seemed under extruded and the overall structure of the object was very weak and broke easily.

I decided to do some calibration prints. I printed a 2-wall cube. Each wall was 0.8mm thick, so all good. When I did the retraction calibration test print something strange happened: the two cyllinders seemed more like spiral skeletons than cylinders. The same test print works fine with a 0.2mm layer height.

I tried changing the following settings (one at a time). Here are the results:

• retraction: print got worse when I disabled it or reduced it from 3mm to 1mm due to lots of stringing and oozing, I think.
• Combing: no effect
• Seam: no effect
• Temperature from 200 -> 220: no effect
• z-hop disabled/enabled: no effect
• acceleration: print improved when I went from 800 to 3000 mm/s2 for the outer wall
• jerk: not much difference between 15 and 25 mm/s for the outerwall jerk
• replaced nozzle with new one: no difference
• replaced stock extruder with titan extruder: no difference
• different brand PLA: no difference

My theory is that the filament is under extruded right after a retraction + move + re-prime. I use cura as slicer and all my print speeds are 40mm/s, travel speed is 150mm/s. Accelerations are 3000 mm/s2 and jerk is set to 25mm/s for all features. Retraction is set to 3mm at 20mm/s (20 mm/s because higher than that the motor starts singing when retracting with the titan extruder).

Below are some picture of the prints. The first one is printed with 2walls. The second one is printed with 3 walls.

My config file: config.g

I'm open to all ideas. Again, this only happens when I print at 0.1mm layer height. The printer used to be an Anycubic Mega i3

@dc42 Cool thanks!

@dc42 I unplugged all the fans and motors and I did some testing after connecting the fan VIN jumper and confirmed 12V on the fan pins.

• Tested the heaters => all OK
• Connected one fan via the anycubic harness and undervoltage/temperature exceeded errors started popping up for all the drivers. This behavior was absent when the fan VIN jumper was absent. There was something which was shorting VIN to GND. I could hear the power supply clicking as it was protecting from a short.
• Connected a fan directly to the fan pins (no harness) and things were working as expected

I think that you are correct because Anycubic uses a wire harness and a PCB to distribute V+ (which arrives though multiple parallel, thin wires) among the fans and the heater block. The GND path is individual for each fan.

So, yes, I think reversing the heater wires would have worked too but of course that's not what I did because I just saw your message

In order to fix the issue, I added an additional wire directly from one of the 12V fan pins all the way to the two fans.

Am I correct to assume that the 12V fan pin can handle the current from both fans simultaneously?

@briskspirit Yes. The fan is a 12V fan. I connected fan VIN (the red wire) to FAN1 V_FAN and fan ground wire to FAN1- . There is no jumper on FAN_VIN.

Hmm... This jumper selects the input voltage according to the schematic. It's not quite clear to me why my fans work, even though I have no jumper at all.

I will test it out this evening. I think you might have fixed the problem.

Thanks for your help.

You are right. It's not a PWM fan. It's just a normal 3-wire computer fan.

Hello everyone,

I have migrated my Anycubic i3 Mega to the duet wifi board over the weekend and I must say I'm very impressed with the quality of the hardware and the firmware. It's worlds better than the original board.

I have noticed that e3d heat sink cooling fan turns off while the nozzle heats up. Once the nozzle reaches the desired temperature, the fan starts spinning again but it has a "hum" to it. The fan is connected to the pwm fan1 output.

I have tried plugging it to an always on fan socket but it does the same thing, except the humming.

The fan is 40mm 12V pwm computer fan (3 wires) but I only use 2 wires.

I would like to have the fan on whenever the hot end exceeds 45C but have no clue how to do it and could not find the answer here. I am using firmware v2.02 RC2 and here is the fan config section

; Fans
M106 P0 S0 I0 F50 H-1                             ; Set fan 0 value, PWM signal inversion and frequency. Thermostatic control is turned off
M106 P1 S1 I0 F50 B1 L1 H1 T45                          ; Set fan 1 value, PWM signal inversion and frequency. Thermostatic control is turned on
M106 P2 S1 I0 F500 H1 T45                          ; Set fan 2 value, PWM signal inversion and frequency. Thermostatic control is turned on

; Tools
M563 P0 D0 H1                                      ; Define tool 0
G10 P0 X0 Y0 Z0 U0                                 ; Set tool 0 axis offsets
G10 P0 R0 S0                                       ; Set initial tool 0 active and standby temperatures to 0C

Any help is greatly appreciated.

Cheers!