Requested speed is not reached
-
@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.
-
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?
-
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.
-
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
-
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?
-
-
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...
-
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
-
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.
-
Could you please Share a Video of your running Extruder? I de assemled my bondtech 100 Times also because switching Stepper Motor it seems all perfekt. Also the other Extruder (ultimaker Clone) Made These Sounds...it also makes this Sound with pressure advance = 0.1
Edit: i bought a bondtech BMG Clone to Check If Mine was faulty...
-
@puddingbaer91 said in Requested speed is not reached:
Could you please Share a Video of your running Extruder? I de assemled my bondtech 100 Times also because switching Stepper Motor it seems all perfekt. Also the other Extruder (ultimaker Clone) Made These Sounds...it also makes this Sound with pressure advance = 0.1
Edit: i bought a bondtech BMG Clone to Check If Mine was faulty...
Taken just a few minutes ago and uploaded to my google drive folder.
https://drive.google.com/file/d/1oEaL72FOPDlCzU3uTm2UajcCdYBtXVWL/view?usp=sharing
-
thank you this is what i expect from my extruder
May i found the problem:
https://photos.app.goo.gl/Krb1Pd1MatLy46S57
look closely to the metal gears. I tightened the screw to max and loosen it till it is possible to move the plastic gear (just a little bit. As you can see the spring is on block (compressed fully). The gears are slipping
if i loosen the srew much more this will also happen. I think this is not normal or what do you think? -
have you tightened the grub screw on the gear with the white gear?
-
yes checked that. Here is also a video with cover (second bearing) mounted.
https://photos.app.goo.gl/PoWPArpmCjFiu4kH7
metal gears still slipping
-
take the one with the white gear apart and post a picture of the shaft and the grub screw.
-
@puddingbaer91 AFAIK that white gear is a press fit onto the shaft and it looks like it might be slipping. Take it apart and clamp the shaft firmly, then see if you can move that gear. It's likely to get worse the longer you print because of the heat conduction from the motor which will soften the plastic and /or make it expand more than the shaft. If that is the case, then you could try a it of epoxy adhesive or contact Bondtech and see if you can get new gear/shaft assembly (but make sure that is the problem first).
Edit - looks like we weer both typing at the same time.
-
Commando Back, talked with bondtech Support and they told me it is designed for using with Filament loaded. Then they doesn't Slip. Reassemled and If i Turn the White Gear fast Back and forth by hand with Filament loaded There ist absolutely No Bad Sound. So i will try it again. If it is Not better i will do a Print without bondtech Extruder to Gear only Extruder stepper
-
the white gear and and bondtech gear should never turn separately, even if there is no filament loaded.
-
i tried again but the same sound. So i unmounted the bondtech bmg and printed without it. The sound comes from the motor because it is skipping steps or something other is wrong with them.
If i hold the motor shaft while printing lines without big speed changes i can't fix the shaft by hand. While fast and often print speed changes (infill) i easily can fix the motor shaft by hand also can turn the shaft in each direction by hand in spite of motor is working.
I tried 3 motors (ACT, original tronxy and original e3d pencake) but all three acting the same. Also lowered the current of xyz to 800mA and let the extruder at 85% current but no change (may it's a little harder to fix the shaft)
Do you know whats going wrong here?
It's a 12V system with 360W power supply
