Identical artifacts/issues on two parts on the same print job

Turbo

@Veti im not sure the exact gearing, but it does drive-->middle pulley, out to two more pulleys on either side. let mee if i can count the teeth

Veti

it says so on the spec page you linked

Gear Ratio: 5.18: 1

Turbo

@Veti not of the motor, im not sure it uses all 20t pulleys, there might be a combo of different counts

Veti

@Turbo
only the one on the motor counts.

Turbo

@Veti oh okay. let me try that value and see what comes of it

Turbo

@Veti printed a 20mm cube at .35layer height. Slicer says it will be a final product of 20.15. actual is 20mm on the dot.

Phaedrux

I think the problem is cold extrusion. Your thermistor settings were really off and you're printing fast and with a thicker layer height really pushing the flow rate. I think that's why the top layer looks more like strings than proper fused extrusion.

Now that you have the proper thermistor settings in place I suggest you go through this guide and recalibrate your extruder and find your maximum flow rate, and from that you take your chosen layer height and width and determine your appropriate print speed.

https://duet3d.dozuki.com/Guide/Ender+3+Pro+and+Duet+Maestro+Guide+Part+4:+Calibration/40

Turbo

@Phaedrux Just finished pid tuning and printing a square to verify settings. Will work on e steps next, although how much could it change due to a bad pid value?

Phaedrux

Well it's more than just esteps, it's finding the max volumetric flow of your hotend and extruder and then adjusting your print settings to stay within that limitation.

Turbo

@Phaedrux
so far e steps look like m92 e407.42
max vol flow rate calculated to be 12.04107575mm^3 / s^2
Max sugg speed for .3 layer height and .6 line width with a .5mm nozzle is approx 66mm/s at 210c.
still going but thought id post an update
printing the box testing for flow. is it okay to use .3mm layer height du to the larger nozzle and thats what i normally print with

Phaedrux

That all sounds right to me.

Compare that to your speed of 80mm/s at an unknown real temp.

Sure you can use whatever layer height you would typically be printing with.

Turbo

@Phaedrux Im starting to see where this might be going. I guess I've been calibrating wrong this whole time. Although another thing im sure is contributing to the messy prints is how shaky the printer is. The thing is sturdy, and uses 2040 extrusion for the frame, so idk. I put a towel under it to help dampen it but again, I dont know a good way to go about this since i dont wannt bolt it to the wall. Shakes the whole table, even with these settings, which I think are pretty low. Unless they aren't?

M566 X1000 Y1000 Z240 E600:600       	 ; Set maximum instantaneous speed changes (mm/min) (OG E600:600)
M203 X18000 Y18000 Z2400 E3600:3600 	 ; Set maximum speeds (mm/min)
M201 X1250 Y1250 Z250 E2000:2000     	 ; Set accelerations (mm/s^2)
M906 X1500 Y1500 Z1200 E850:850 I50 	 ; Set motor currents (mA) and motor idle factor in percent

Turbo

@Phaedrux things begin closing up at 85%. seems too low considering you mentioning values within +/-5 of 100%, but everything else I calibrated according to the guide.

Its also under the expected width of 1mm by about .1 to .15mm, despite the gaps being closed up. does this indicate something wrong in calibration or is the solution to bump up the extrusion rate?
Final edit: using 98% flow gives me the expected 1mm thickness. despite 85% being where the gaps close

Phaedrux

Sounds like you've got your extrusion multiplier and esteps dialed in now.

I've got a Dbot as well (300x300) with a titan aero and 0.6 nozzle and V6 hotend, so not far off what you have.

I usually print with 0.65 width, 0.3 height, and 60-70mm/s speed. 600-900 jerk, 600-1200 accel.

In prusa slicer you can enter your volumetric limit in the speed tab. In your case, 12. That will make sure you aren't exceeding that flow rate, which can be a handy safety net.

Turbo

@Phaedrux good to hear I'm moving in the right direction. So should 98% flow be okay despite having the gaps close at 85%?

Phaedrux

@Turbo said in Identical artifacts/issues on two parts on the same print job:

So should 98% flow be okay despite having the gaps close at 85%?

Yes. the gaps closing shows you the minimum flow. Due to the way the plastic forms a cylinder when extruded the flow math can get pretty weird in slicers. 98% is basically perfect.