Requested speed is not reached
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@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
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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...
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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.
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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?
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@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.
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@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?
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@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) -
@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
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@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)
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@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
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@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.
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I guess there is also a chance that the motor current is too low to provide the required torque, causing the motor to skip steps when jerk is applied. What motor are you using, and what extruder motor current have you set?
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There should be nothing loose.
I use These ACT steppers:
https://www.roboter-bausatz.de/2554/act-nema-17-schrittmotor-17hs5425l20p1-x2
Current in Data Sheet is 3.1 Ampere
It's in German i Hope Google can helpCurrent ist set to 1300mA.
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see
https://duet3d.dozuki.com/Wiki/Choosing_and_connecting_stepper_motorsSo the usual practice is to set the motor current to no more than about 85% of the rated current. Therefore, to get maximum torque out of your motors without overheating them,
also
Duet 2 WiFi and Duet 2 Ethernet (maximum motor current 2.4A) => Stepper motor rated current <= 3.0A
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Okay Data seems to be wrong on the Website. My Motor ist labeled with 2.5A
https://photos.app.goo.gl/CSqKTi9TxJZBSTX27
Should i ran the Motors near 85% ? 2A?
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Thank you i will try and Report. But can't Imagine that this causes the Problem because the Motors are already very Strong at 1.3 ampere...
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tried with 2100mA but even with pa=0.1 the same sound but now only at high speed when printing infill. While printing slower the sound is now silent. Tomorrow i will try another stepper for extruder drive and report results
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okay also with another stepper (original from TronXY) i get the same sounds
Only reducing jerk to 600 will result in good sound -
@puddingbaer91 I say again that none of my 5 Bondtech BMGs make that noise. You said above that "there should be nothing loose" but have you actually taken it apart and checked?
Edit. The only reason why reducing "jerk" helps the sound is that it effectively reduces pressure advance so either don't use pressure advance at all or fix the problem with the extruder.
