Pancake stepper skipping
-
Here you can see the extrusion problem on a purge line
-
Typically it's recommended to run the stepper at 80% of the rated current which is 0.7A*0.8 here.
In case you are interested in a good stepper for a geared direct extruder, this one has good reputation https://www.bondtech.se/en/product/nema-17-motor-slim-power-ldo-42sth25-1404mac-0-9-degree/ . It's also 0.9 deg and will give you higher E step resolution.
BTW, what voltage do you use for the stepper? (don't be misled by the 12V specification in the link you posted, it's incorrect and it's non relevant).
-
Woops, forgot to mention that, it's running at 24V.
So setting it to 80% of max current would be 560mA, which is less than the setting of 600mA I have now.
Does that mean the stepper is "useless" for this? -
Are you sure the temperature is correct?
Do you have the thermistor values correct?
If you increase the temp 10c does it extrude more smoothly?
-
@hmortensen In addition to the above comments, how sure are you that it's the motor skipping steps? Many of these Bondtech clones have other problems such as the teeth that grip the filament not being deep enough, the gears wearing because they aren't hardened, warped housings, poorly aligned gears etc.
-
@hmortensen said in Pancake stepper skipping:
Hi
I've mounted a pancake stepper on a Fysetc dual drive extruder, but it skips steps now.
Link to the stepper i've bought:
https://www.trab.dk/da/stepper/400-nema17-pancake-stepper.htmlCurrently it's set to 600mA, but can I go higher to fix it?
Or can I do something else?Yes you can go higher. Stepper motors are normally rated with both phases energised; but microstepping drivers only energise one phase with the full current at a time. So it should be safe to increase current to at least 0.8A. Of course, this will make the motor hotter.
However, if this is a new hot end, the real problem may lie elsewhere as other have mentioned.
-
Thanks for the current clarification.
I've reassembled the hotend and afterwards tried raising the temperature to 220 (PLA) but the problem persist.
I've also tried another spool with PETG and same problem.
I've also tried the stock extruder stepper with no luck.If I extrude with G1 F400 E100 it extrude smoothly, but if I do F500 it stutters at the end of the move.
Any ideas or should I make a new post with a clearer writeup, as it doesn't seem to be the stepper afterall.
-
@hmortensen IMO that is normal behaviour.
500 mm/min is about 8 mm/sec, which is a LOT of filament to feed.
IMO, if you crank the heat up a lot you may be able to achieve this, as long as you have a large enough nozzle.
As a reference, 5 mm/s is where I define the "maximum reasonable extrusion amount" (for a normal 0.4 nozzle setup).
-
Did you go through the volumetric flow rate calibration test I linked along with the extruder calibration? As @bot says, it sounds like you're possibly reaching your limit.
Test the PLA at 250 and see if it goes more smoothly. You probably wouldn't want to print at that temp but it would give an indication if you were melt rate limited.
-
I "solved" the problem by ordering original hotend and extruder.
The stepper is running at 700mA and it's not getting too hot to hold my hand on.
Thanks for the help.
-
@Phaedrux said in Pancake stepper skipping:
Did you go through the volumetric flow rate calibration test I linked along with the extruder calibration?
Where did you linked this test?
@hmortensen I'm using E3D "slimline" motor
https://e3d-online.com/slimline-motor
their version of pancake motor that I got for my titan aero, but since I'm not using the aero I used that motor in combo with BMG geared extruder. Trough .6mm nozzle I'm doing .7mm wide, .5mm layer 80mm/sec PETG (maybe it can go faster, have not tried yet) -
@arhi said in Pancake stepper skipping:
Where did you linked this test?
I guess I didn't link it. I must have been thinking of a different thread.
But this is the link I was talking about.https://duet3d.dozuki.com/Guide/Ender+3+Pro+and+Duet+Maestro+Guide+Part+4:+Calibration/40#s165
-
I found this calculator for figuring how the flow rate for extrusion.
https://www.printitindustries.com/pages/print-speed-calculator
-
@hmortensen
This site has serveral pancake stepper motor, you can have a look
https://www.oyostepper.com/category-64-b0-Pancake-Stepper-Motor.html
