Hello fellow reprap.
how can i get rid of these blob ?
i’ve recalibrate the extruder: it does not seems to be over extrusion.
try to tune the temps : i’ve try from 185 to 200C
i’ve try higher/lower retraction speed
higher/lower retration length.
i’ve try to change the speed from 30 to 150mm/s
i’ve try “z change” when retracting of cura…
i can’t get rid of them.
setup:
maxi kossel,
70cm bowden,
E3D v6,
pla 1.75 @ 190°C
layer .2,
speed 60mm/s
latest cura.
Your Filament is wet. 50 degree for 1-2 hours.
Could be some popping in the filament. What brand are you using.
it is not the filament, (brand dutch pla from reprapworld).
i’ve try it on my 3dr simple and the print are perfect. (i’ve try 3 different filament)
i suspect the extruder loose steps when retracting, but how can i check that ?
extrude temperature, try 165deg C
at 185 the layers didn’t bound well. 165 is lower thant the marlin min extrusion value.
i’ve give more current to the extruder and lower the retract speed, it seem to generate less blob, so i’m pretty sure that the extruder skip steps. but i don’t know how to verify.
I think the extruder didn’t fit well the printer.
i use the 3DR simple extruder. must i try the airstripe one ? did he need a geared stepper or a normal stepper will work ?
Even with the extruder calibrated it may still be over extruding. I have mine calibrated perfectly (100mm produces exactly 100mm) but I still have my flow rate set at 80% or I get those blobs and crappy top surface.
@Ryan_Hescock_Stanos and I have the same issue. 103.6 gets me a perfect 10.0mm of filament for 10.0mm of extrusion. Messing with your flow rate in your slicer could make a difference. I needed to take about 5% off of mine. Just did it the other day after months of printing.
What are your settings for retraction, acceleration, jerk and travel speed? Are these blobs located at the start or finish of the perimeter loop?
@Matthew_Satterlee they look like they are around a lot of the perimeter. Usually slicers do layers moving up a line if there isnt a huge change like this (like the amount of portions doesnt change) unless you have a vase setting on (I believe there is a better term).
@Griffin_Paquette , Cura has settings to change seam positions to be aligned or random… To me this looks like he has Z-lift enabled and the extruder is oozing during the up/down movements.
my retraction is 40mm/s ( i’ve try retraction of 4 to 6 mm)
in firmware
Eaccell 2500 (ive try from 1000 to 5000)
ejerk 15 (didn’t change it is the same as my 3dr simple where i didn’t get the problem with the same extruder design)
travel movement speed 300mm/s ( i’ve try from 150 to 400)
Try cleaning your nozzle also what are you using to grip the filament the teeth and printed gears can be inconsistent
I got something similar, but at the stern end. It looks like mine was caused by the low infill not providing enough support for the deck layers, and some filament that was extruded into “thin air” got dragged to the perimeter. I bumped up infill to 25% and am reprinting (fingers crossed).
i think i found it, it was the DELTA_SEGMENTS_PER_SECOND in marlin for delta, causing miro pauses. i lower it from 200 to 150, seems ok now.
