Odd print problem

Quote
nophead
The retraction distance should be just enough to stop ooze on long travels. You can have the retract speed too fast though, so it doesn't have time to flow from the nozzle at the start.

My comment was mostly to acknowledge the speed mod actually made a difference, lowering the distance solved the problem but my blobs still appear. I have kept the high retraction speed as per recommendation from Neil.

Edited 1 time(s). Last edit at 04/24/2015 09:15AM by hsbontop.

Been running with 23:27 gears for a while now, only slight improvement of the blobs however. It seems like long travel distances worsen the issue and as I have had slight formation of thin strings maybe temperature is to blame. Attached is a 30 mm/s print with good result.

If you get strings the retraction distance is not big enough.

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[www.hydraraptor.blogspot.com]

Increased retraction and the strings, that was more like fibers, disappeared. Printed a hole lot of calibration cubes to get the flow correct and realised the Slic3r multiplier was way low... The reason for this was the micrometer used measured single wall + layer offset, when measuring only three layers the width was correct when the top infill looked nice. The result is next to perfect prints.

Turned back to skeinforge to print a few spares and realised there must be some setting seriously wrong causing over extrusion at the top layer.
When extruding 100 mm PLA at 185c exactly 100 mm goes in, single wall is at this point more or less spot on (0.5 mm in skeinforge and 0.55mm in real life which should be about right as no support is provided from adjacent paths).
Enclosed is a comparison top to bottom of prints with multiplier 0.94, 0.9 and 0.86 (entered inverted in skeinforge).


The top layer does not become smooth until a multiplier of 0.86, but this causes the perimeters to come apart. Also the over extrusion seem to appear mostly during acceleration.
I have tried lowering the temperature to 175c, below that the resistance was to great.
As the same phenomena appear in slic3r I would guess this might be filament/hardware/marlin related.
Any idea's what to test?

hey guys... its been a while... well iv run into a odd print issue i cant seem to figure out... for some reason if i try to print anything with round holes or curved shapes, the printer vibrates like its struggling to print. i turned the jerk down to 10 and it got much better but none the less still does it...see pics...in the 2nd image u can see the jerk setting change little past half way thru the print... it was at 15..i reset to 10 on the XY Jerk... but the vibrations are still noticable...

and yes i know i have dirty hands, im a motorcycle tech and at work when photo'd...

thoughts?

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Nophead Mendel90 Remixed in aluminum
Marlin v2.0
Matterhacker Control (latest)
Ramps 1.4
Sainsmart LCD
MK2B heatbed
E3dV6 hotend .4mm tip
1.75mm filaments
dedicated 12v33a psu
dedicated 12v5a laptop psu mod

Looks like the comms is too slow for the short segments. Try printing from an SDCARD.

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[www.hydraraptor.blogspot.com]

tryed that, same result

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Nophead Mendel90 Remixed in aluminum
Marlin v2.0
Matterhacker Control (latest)
Ramps 1.4
Sainsmart LCD
MK2B heatbed
E3dV6 hotend .4mm tip
1.75mm filaments
dedicated 12v33a psu
dedicated 12v5a laptop psu mod