Topics created by Denis

@FHesse I think the simplest solution for now is to set up a macro that does this:

use M451 to switch out of laser mode to free up the laser control pin use M950 to configure the laser pin as GpOut pin use M42 to set the desired PWM on that pin use M291 to prompt the user to press OK when focusing is complete use M42 to turn off the laser use M950 to deconfigure the GpOut port use M452 to reselect laser mode.

@dc42 0.9 degrees. These are Wantai motors, 2.4A with a fairly low inductance
I did not try this with a 30mm fan, but with the 4010 fan turned off, the repeatability was better. Although accuracy of 0.02 suits me, if only the accuracy of calibration affects only the first layer. If this affects print quality further layers, of course I will fight for better accuracy.

@Denis Your original post's pictures show a large roundish blob, probably created from oozing between the times when you paused and cancelled the print. IMO such large round blobs only occur when you're way over temp and the filament is almost in a liquid state. In your place I'd try lowering the temp by 10-20 C and see what happens

see https://duet3d.dozuki.com/Wiki/Smart_effector_and_carriage_adapters_for_delta_printer
Section Compatibility with other electronics and firmware

@denis, I suspect it is at least partly a temperature issue. From @Veti's post above:

@veti said in Quality problems. Duet vs. Marlin:

if your bed is a semitec thermistor see the configurator for b and c values for that thermistor.
the marlin thermistor file says B4100 for thermistor 13.

If your Marlin config assumes B4100, that will give you significantly different temperatures from RepRapFirmware which you have configured for B4267.

I followed some advice from here and got some results to report for reference:

Switching to a zero-crossing from random-crossing SSR did not visibly affect the light flicker issue. Switching from bang-bang mode to PID at the bed heater did not affect the horizontal banding issue. I was able to further tune the PID and keep light flicker to a minimum. The Z axes construction was worse than I expected. I could measure +/-50% variation every Z motor revolution with just a basic electronic caliper. Apparently the Z screw rods were misaligned so just a little rod bend was being exaggerated. The weight of the bed was high enough to press the Z stepper rotor downwards on high acceleration moves (this obviously depends on its construction), so I added some flange bearings at the bottom. The Z smooth rods were not really smooth in the Z direction and needed some 800 or more grit sanding. I remodeled and fitted bigger, bulkier variants of all brackets, couplings, etc on the Z axis.

Now after improving 2 out of 4 Z axes the banding is nearly gone!

@denis said in About steppers:

dc42, Thank you, David. I was waiting for your answer) I have two 0.9 motors from the FlingBear Tornado and I rearranged them on Tevo LM. The third motor is waiting. Now I test their work on the 32 step. Should we expect problems if you enable dynamic interpolation? Will I lose microsteps?

On the Duet WiFi/Ethernet, microstep interpolation only works when the microstepping is set to x16. There is no reason to set microstepping greater than x16, especially when using 0.9deg motors.

Send M562.

https://duet3d.dozuki.com/Wiki/Gcode

It's possible you have a broken bearing on either end of the large drive gear of the titan aero. It's very easy to over tighten the bolt.

I looked print script. M84 is used at the very end.
M117 Layer end
M104 S0; turn off extruder
M140 S0; turn off bed
G91; Relative positioning
G1 Z20 F9000
G90; Absolute positioning
G1 X160 Y270 F9000
M84; disable motors
M106 S0
M300 S2000 P500

My mistake was at the beginning of printing.

@denis said in Configure nonlinear extrusion:

@dc42, I ask for help. I use an extruder, which at rest has 840 steps to extrude 50mm filament. For extruding 50 mm at a speed of 1 mm / s, 750 steps are required. If you take 750 steps, then the next chart looks like
2 mm / s - 45 mm
3 mm / s - 43 mm
4 mm / s - 43 mm
5 mm / s- 43 mm
6 mm / s - 42 mm
Using tables that I found on the forum gives a negative value of "A"

That makes sense because you have a big drop between 1mm/sec and 2mm/sec and a smaller drop between 2mm/sec and 3mm/sec. If you are sure those measurements are correct and reproducible, don't worry about having negative A figure.