Requested speed is not reached

[deckingman]

@puddingbaer91 I would suggest that if you need that sort of pressure compensation, then there is something seriously wrong that is causing too much pressure inside the hot end. That could be for any number of reasons, for example a partial blockage or too much part cooling air being deflected back off the build plate and dropping the temperature at the nozzle tip. I use a pressure advance value of 0.4 with my Diamond multi filament hot ends and that is considered high by many people. Most (but not all) users with "conventional" hot ends run values in the order of 0.1 to 0.2, even with long Bowden tubes. So there has to be something seriously wrong if you need values in excess of 1.6.

[deckingman]

@puddingbaer91 said in Requested speed is not reached:

@deckingman said in Requested speed is not reached:

@puddingbaer91 said in Requested speed is not reached:

@deckingman said in Requested speed is not reached:

@puddingbaer91 said in Requested speed is not reached:

.........................my pressure advance value is: M572 D0 S1.624 .........................

S1.624! Seriously?

hey deckingman instead of only talking: how could i reduce the value? I have done the calibration posted here in duet forum and ended with this. So please tell me how to reduce

I don't like the calibration method that is on these forums. This is an old blog post but it details the method I use which works for me https://somei3deas.wordpress.com/2018/01/15/an-attempt-to-investigate-pressure-in-the-extrusion-system-with-a-diamond-hot-end/

thank you but even the autor from this article used a pressure advance value of 0.7 with much shorter bowden tube... Don't know what i could do to reduce it. maybe printing hotter?

I am the author that post - that is my blog I linked too. As I said in my post above, and as described in my blog, those tests were done with a Diamond hot end which uses 3 Bowden tubes and 3 extruders and has a massively large melt chamber. Since changing my extruders from E3D Titans to Bondtech BMGs, I have reduced the PA to 0.4.

[Veti]

@puddingbaer91 said in Requested speed is not reached:

M305 P0 T100000 B4138 C0 R4700 X2 ; Set thermistor + ADC parameters for heater 0 and remap it to channel 2
M143 H0 S80 ; Set temperature limit for heater 0 to 80C
M305 P1 T100000 B4138 C0 R4700 ; Set thermistor + ADC parameters for heater 1
M143 H1 S250 ; Set temperature limit for heater 1 to 250C

the tronxy x5s on marlin uses thermistor table 1
which is
// R25 = 100 kOhm, beta25 = 4092 K, 4.7 kOhm pull-up, bed thermistor
4138 is the default in the configurator. so you might be printing at the wrong temperature

[dragonn]

Please also check you bowden tube mounting, if you fittings are lose and the tube moves when retraction/extruding back and forward they you will get problems like to high PA.

[PuddingBaer91]

@veti said in Requested speed is not reached:

@puddingbaer91 said in Requested speed is not reached:

M305 P0 T100000 B4138 C0 R4700 X2 ; Set thermistor + ADC parameters for heater 0 and remap it to channel 2
M143 H0 S80 ; Set temperature limit for heater 0 to 80C
M305 P1 T100000 B4138 C0 R4700 ; Set thermistor + ADC parameters for heater 1
M143 H1 S250 ; Set temperature limit for heater 1 to 250C

the tronxy x5s on marlin uses thermistor table 1
which is
// R25 = 100 kOhm, beta25 = 4092 K, 4.7 kOhm pull-up, bed thermistor
4138 is the default in the configurator. so you might be printing at the wrong temperature

interesting what do i have to change here?

is this right?

M305 P1 T100000 B4092 C0 R4700

[Veti]

the ender 3 uses epocs 100k as well
see
https://duet3d.dozuki.com/Guide/Ender+3+Pro+and+Duet+Maestro+Guide+Part+2:+Configuration/38
step 7 (the r2200 is maestro specific)

[PuddingBaer91]

@puddingbaer91 said in Requested speed is not reached:

M305 P1 T100000 B4092 C0 R4700

sorry i forget that i use this thermistor: https://www.ebay.de/c/22025877022

[Phaedrux]

@puddingbaer91 said in Requested speed is not reached:

@puddingbaer91 said in Requested speed is not reached:

M305 P1 T100000 B4092 C0 R4700

sorry i forget that i use this thermistor: https://www.ebay.de/c/22025877022

That's a heating cartridge.

[Veti]

@puddingbaer91 said in Requested speed is not reached:

sorry i forget that i use this thermistor: https://www.ebay.de/c/22025877022

that is some random other stuff. not a genuine e3d thermistors

according to a comment on amazon
https://www.amazon.de/NTC-Thermistor-Patrone-V6-Hotend-Prusa-i3-RepRap-3D-Drucker/dp/B077MLDBF1
the beta value for that is 4276

edit:
it might be a semitec 104-GT
https://atcsemitec.co.uk/wp-content/uploads/2019/01/Semitec-NT-4-Glass-NTC-Thermistor.pdf
in that case use
β: 4725 K
C : 7.060000e-8

[PuddingBaer91]

@veti said in Requested speed is not reached:

4276

hey thank you for your help. I asked the seller for data. Also ordered PT100 daugtherboard and PT100 sensor. Will inform you if i have new results

[PuddingBaer91]

because i can't wait for the new sensor i have done the calibration for pressure advance again at 245°C and i ended up somewhere at 0.8 - 0.9. It really seems to be a temperature problem.

Could you tell me if the temp read out drops or goes up by lowering the B value? Because you found out lower values i am interested in if this is the right direction for getting lower temps so i have to heat up more...

[dc42]

Increasing the beta value reduces the temperature reading, for temperatures above 25C. Therefore, if you think the hot end temperature is lower than the reading, increase the beta. If you think the hot end temperature is higher than the reading, reduce the beta.

[PuddingBaer91]

thank you for your help.

Today i installed the PT100 sensor and now it's much better. Now i need a pressure value of 0.7. But another problem is the higher Extruder jerk (600mm/min instead of 300). Because of this i hear the extruder and that sound is not cool as with jerk=300. But to get the full speed i need a higher value like you said. Using Bondtech extruder.

Do you ignore this sounds and is it normal? I read some articles where people use 3000mm/min but i can't imagine how terrible this will sound... Is there another thing i have to adjust to get rid of this sounds?

[deckingman]

@puddingbaer91 said in Requested speed is not reached:
................But another problem is the higher Extruder jerk (600mm/min instead of 300). Because of this i hear the extruder and that sound is not cool as with jerk=300. But to get the full speed i need a higher value like you said. Using Bondtech extruder.

Do you ignore this sounds and is it normal? I read some articles where people use 3000mm/min but i can't imagine how terrible this will sound... Is there another thing i have to adjust to get rid of this sounds?

600mm/min (10mm/sec is still far too low IMO). I use 3600 mm/min and run Bondtech BMGs (5 of them). I'd expect that with extruder jerk set to 3000+ then you might even be able to get PA down further. What sort of sound do you get? Is it a clicking noise or something else?

P.S. I haven't looked at this thread for a while but you seem to have made good progress since I spotted that you were using crazy high PA.

[PuddingBaer91]

@deckingman said in Requested speed is not reached:

@puddingbaer91 said in Requested speed is not reached:
................But another problem is the higher Extruder jerk (600mm/min instead of 300). Because of this i hear the extruder and that sound is not cool as with jerk=300. But to get the full speed i need a higher value like you said. Using Bondtech extruder.

Do you ignore this sounds and is it normal? I read some articles where people use 3000mm/min but i can't imagine how terrible this will sound... Is there another thing i have to adjust to get rid of this sounds?

600mm/min (10mm/sec is still far too low IMO). I use 3600 mm/min and run Bondtech BMGs (5 of them). I'd expect that with extruder jerk set to 3000+ then you might even be able to get PA down further. What sort of sound do you get? Is it a clicking noise or something else?

P.S. I haven't looked at this thread for a while but you seem to have made good progress since I spotted that you were using crazy high PA.

thank you i will try. What acceleration you use for bmg extruder?

[deckingman]

@puddingbaer91 said in Requested speed is not reached:

thank you i will try. What acceleration you use for bmg extruder?

Bear in mind that I have 5 BMGs feeding a Diamond "mixing" hot end so my settings might not be relevant to your situation but this is what I use.

M92 X80 Y80 U80 V80 Z3200 E409:403:407:405:403 ; steps per mm
M566 X1200 Y1200 U1200 V1200 Z100 E3600:3600:3600:3600:3600 ; maximum instantaneous speed (mm/min)
M203 X50000 Y35000 U50000 V35000 Z450 E3600:3600:3600:3600:3600 ; maximum speeds (mm/min)
M201 X1000 Y1000 U1000 V1000 Z100 E3600:3600:3600:3600:3600 ;accelerations (mm/s^2)

[PuddingBaer91]

@deckingman said in Requested speed is not reached:

600:3600:36

thank you. I wonder why we need these high values. Even the Ultimaker2 only uses 300mm/min for e-jerk?!?

see: https://github.com/Ultimaker/Ultimaker2Marlin/blob/master/Marlin/Configuration.h

[deckingman]

@puddingbaer91 said in Requested speed is not reached:

thank you. I wonder why we need these high values. Even the Ultimaker2 only uses 300mm/min for e-jerk?!?

So what? The Ultimaker2 also has a cantilevered bed that flops around like a field or corn in a breeze. Unless you set it on a concrete slab, you'll likely upset the layer height just by walking past the printer. So I wouldn't hold it up as being any sort of standard to which all printers must aspire (good marketing hype though).

On the subject of E "jerk", the only time it will come into play is either when pressure advance is used or if it is set lower than the instantaneous speed threshold of the X or Y motors. In that case, all it does is slow the entire print down. "Jerk" is the speed threshold to which axes and the extruder must slow down before a change of direction can occur. In RepRap firmware (which the Duet uses), "Jerk" is not applied to the start of a move from zero speed - only when the print head is moving and there is a change of direction. So before a change of direction can occur, the printer will slow down to the lowest "jerk" speed of either X, Y or E. So unless you want the print head speed to be controlled by extruder "jerk" rather than X or Y "jerk", then set it higher than those two axes. ("Axes" in this case is the plural of "axis" - not something that is used to chop wood)

[PuddingBaer91]

@deckingman said in Requested speed is not reached:

000

i made a video to show what my extruder sounds like with these high jerk values @ PA=0.6:

https://photos.app.goo.gl/jUapfqh28hwszUDT8

It's like the extruder will blow up in a few seconds.

Can't belive you print also with these sounds. Also the print is not possible as you see. Even with pa=0.1 it makes these sounds

[deckingman]

@puddingbaer91 None of my BMGs make that noise. The movement is visually the same as yours but not the sound. I'd say there is something loose somewhere. Maybe the hobbed gear on the shaft? Maybe the Bowden fitting inside the housing? Maybe worn teeth? Or maybe it's just the Bowden tube a bit loose in the fitting. You need to take the extruder apart and investigate.