Ok nevermind, i overlooked the fact that my starting script had a M82 in it. I changed that and it works.
The top one is a variation between Pressure advance 0 and 0.2, the second is a taller version for the PA of 0 to 0.5 and lastly the bottom one is between a PA of 0 and 1.
I´m using a super short "bowden" of around 120 mm, see picture.
BMG clone, genuine capricorn tube and e3d Volcano copper block, 0.4mm nozzle. Printing Tiertime ABS filament @260°C and 70°C Chamber temperature.
My Jerk is set to X500/Y600/E200. Acceleration is set to X1000/Y1000/E1000.
Looking at the results i need a PA of 0.55. Can this be? It seems a little excessive for a more or less direct drive extruder. Is it because of the volcano and the ABS filament?
Also, in the long segment the centers seem to bulge up, even at the part that had a maximum of 0.5 PA which is close to the needed value. I never get a consistent extrusion throughout like the other pictures posted.
What is the culprit of that? What do i need to change to have the extrusion in the fast segment even?
I have checked nonlinear extrusion but have not configured it since my extrusion stays consistently at 100% up until 7mm/s, at 8mm/s it is at 98.8% and at 10mm/s it is at 96.8%. If i configured nonlinear extrusion, the square fitment nature would mess up my extrusion below 7mm/s. It may need more variables.
@DigitalVision Thanks for the script, it works perfectly!
Some of the figures in that table are misleading, and some are plain wrong:
Thermistor resolution "Up to 0.16°C" doesn't mention that for a wide-range thermistor, the resolution is likely to drop to 10C or even worse towards the extremes of the range. This makes it difficult or impossible for the firmware to know whether the thermistor is present before turning the heater on.
Thermistor accuracy "1°C without calibration" is only likely to be true over a very limited temperature range, e.g. close to 25C (or whatever temperature the nominal resistance is specified at)
RTD resolution "1.2C" is completely wrong, for the Duet3D PT100 daughter board it is 0.03125°C
Thermocouple resolution "0.5C" is likewise wrong, for the Duet3D thermocouple daughter board it is 0.0078125°C
The response time of any type of temperature sensor is completely dependent on the packaging
Thermistors are for budget 3D printers. If you want to know your hot end temperature accurately, use a PT100, or a thermocouple if you need to measure very high temperatures. A PT1000 may also be a reasonable option if you don;t mind the resolution being a little lower than for a PT100. See our advice at https://duet3d.dozuki.com/Wiki/temperature_sensors.
@grizewald said in Motor noise and print quality:
@sethipus said in Motor noise and print quality:
I don't recall what printer you're using @grizewald, but is it using gt2 belts to drive the X/Y access? And if so, are there places where your toothed belts are running around idler pulleys, whether smooth or toothed?
My printer is the V-Core from RatRig. They've just released version 2, so the pictures for version 1 are no longer present on the site, but it's big Core-XY based on OpenBuilds parts with a nominal 300 x 300 x 300mm build volume.
It looks like this:
It does use GT2 belts and apart from the pulleys, the belts go around OpenBuilds smooth idlers. It would be very difficult to arrange twists in the belts so that every idler had a smooth belt side running around it.
I had a close look at my D-Bot's setup and a single twist (per belt) immediately after the stepper itself, on the outer belt run (ie: not the one that must remain parallel) will ensure that the back side of my belt runs against the idlers for the rest of the run. When I first tried addressing the corduroy effect, I swapped out the smooth idlers for toothed ones, but it didn't really help. There is this microscopic jump in the X and Y motion as each tooth engages (or each ridge on the belt hits a smooth idler) that results in very slight extrusion rate differences on a printed straight line, and that's what's causing this effect.
Anyhow, CoreXY is CoreXY and I'd be surprised if your printer's belt runs are really any different than mine in this regard. Is there really no way to introduce a twist in the outer belt run away from each stepper, to get smooth belt backside against the idlers?
ETA: I really wish I'd built my D-Bot to the 300x300x300 version. I built mine to the 200x300x300 version. In theory it wouldn't be too hard to change mine, just four lengths of v-slot rail and a new build platform, but I just can't bring myself to do it. What concerns me more than that extra 100mm of Y axis is getting my printer enclosed. I've tried printing PC and nylon and ASA and whatnot without an enclosure without a lot of success (well, had more success with the nylon than the other two). My biggest thing is that I've got things that would be inside the enclosure if I just put a large box over it that I don't really want heated, like the power supply, Duet Wifi controller, and steppers, plus the bowden tube is sticking up from the extruder, which is mounted to the top rear frame rail. One of my next big upgrade projects will be to move everything that might be heat sensitive out of the build volume area, and figure out some attachment points or whatever for some materials that can enclose the build volume itself.
@phaedrux said in Another question about setting "Z=0 Datum":
Logically you'd think it should be the probe that's at the center of the bed. That's how I do it anyway.
I believe @dc42 Added that section with the 2.03 update. Perhaps he can clarify.
It seems to be that the probe should be centered also.
Perhaps we will hear from dc42.
https://www.mouser.de/datasheet/2/362/semitec usa corporation_gtthermistor-1202937.pdf
The e3d thermistors are 104GT-2 Which have a beta value of 4276. See the above datasheet.
Steinhard Hard is often used to derive a precise temperature of a thermistor, since it provides a closer approximation to actual temperature than simpler equations, and is useful over the entire working temperature range of the sensor.
The Semitec Thermistor is widely used and produces good results. The B3950 Thermistors as you say become very inaccurate at high temperatures as there are different ones that just behave the same in the 25-50C quoted range.
I moved to a PT1000 because of all of this as well.
@dc42 said in Question about G29 S2:
No, it doesn't ignore it.
If you home Z at the same XY point as one of the points in the G29 mesh, then the height error in the height map should be zero at that point. Alternatively, use G29 S2 to clear the height map before homing Z, and reload it afterwards.
G29 S0 (or just G29) clears the existing height map before probing starts.
Thanks very much. That is what I needed to know.
@petera said in Resuming Printing after Power failure:
mmm ok. The duet3 supports this right? What would stop the config from saving this? Then perhaps only certain power supplies have this feature? This is me guessing?
Are you really using a Duet 3? The firmware stack for Duet 3 does not yet support the resurrect feature.
@Phaedrux Btw just got my gt2 Gates belt, and I've reprinted the left and right rear corner braces where the pulleys go with a remixed version that allows the pulleys to be replaced without having to disassemble the whole top of the frame. Doh! Can't believe the original design has the lower pulley screws facing down. For good measure I also printed out versions of the stepper mounts that allow the belts to be tightened at the stepper motor, rather than at the print carriage. Either tonight, or latest this weekend, I'll pull the whole top end apart and rebuild it, replacing the four corner pieces, and using the original smooth bearings in place of the toothed pulleys I've got in there now, and using the twist of the belt to keep the flat belt backs against the flat bearing/pulleys. Assuming this was always the source of my "corduroy" pattern artifacts, my prints should come out better than ever.
I've never used M122 before. I'll have to add it to my ending scripts and get that output as default from now on. Sounds like a useful diagnostic.
i call G29 from the initial G Code for printing and do the G32 z adjustment manually from time to time.
You could also do G32 and G29 in the initial printing g code if the extra time does not bother you.
As well as the spring effect of filament and motor there is also backlash if using gearing or a Bowden tube that has to be slightly bigger diameter than the filament. @dc42 does the pressure advance separate these two effects and compensate for them independently? I.e. to get over backlash you would want a very fast movement and then a slower accelerating speed once the filament is engaged.
M208 sets the axis travel, which is the whole distance each axis can move. For example, your X axis endstop is activated beyond the point where the nozzle is on the edge of the bed. So the X-23 tells the Duet where the edge of the bed is from the endstop. So your use of M208 is correct.
The reason for this is to allow for an offset probe, or for the nozzle to go off the bed (if you need to change filament).
You can also set the axis maximum movement. If your bed is 200mm x 200mm and Z can move up 200, you can set M208 to:
M208 X-23:200 Y0:200 Z0:200
This means that each axis won't try to move beyond the bed.
@classicstyle said in Mesh Calibration Issues (Duet Maestro 1.0, FW 2.02, BLTouch):
Well, I found tonight that I am a moron. I had forgotten two X-gantry retaining screws to hold the gantry rods in place on one side. There was a non-trivial amount of torsion on the print head as a result. Wondering if that was the source of the "scraping" of the print.
It sounds like you found the smoking gun!
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