New printing problem.

[paul9 20]

Hi guys.

I have never had these problems.

I think it is as if the extruder is stopped in an instant more or rests on the printed side before moving and let these ugly marks on the print.

attaching photos to better understand my problem.

[rowiac 53]

Have you looked at the slices in the gcode to see if those marks appear there?

[komodo 4]

Are you printing with fans on? It looks like that part of the print has a very small surface area so the heat isn't dissipating very quickly so the material is oozing a very small amount. Try either turning on the fans or increasing the speed to help reduce the heat.

BR

Rich

Edited October 7, 2016 by Guest

[geert_2 557]

I also have this on small parts, for example on fine text of a few mm height. It indeed seems to be caused by the head stopping for a fraction of a second while retracting, and then moving on.

I can reduce it but not eliminate it by reducing temperature and printing slower, for PLA down to 180°C or 190°C, and 20mm/s, for small parts.

[IRobertI 517]

Most likely caused by the small delay while retractions are happening like geert says. You might be able to get rid of it by lowering temperature a little bit, disabling retractions and increasing travel speed.

You will likely get some stringing doing that but it might be that those are small enough that they are easier to remove than trying to get rid of the tiny blobs.

[paul9 20]

Most likely caused by the small delay while retractions are happening like geert says. You might be able to get rid of it by lowering temperature a little bit, disabling retractions and increasing travel speed.

You will likely get some stringing doing that but it might be that those are small enough that they are easier to remove than trying to get rid of the tiny blobs.

 

Thank you. I then try to increase the speed of retraction of 1 or 2 mm / s

[paul9 20]

I also have this on small parts, for example on fine text of a few mm height. It indeed seems to be caused by the head stopping for a fraction of a second while retracting, and then moving on.

I can reduce it but not eliminate it by reducing temperature and printing slower, for PLA down to 180°C or 190°C, and 20mm/s, for small parts.

 

Thank you, the press seems to me that it was to 203 ° C with the next try to print to 195 ° C

[the_mechanical 0]

Hi,

i'm not sure, but maybe this is the same problem, only in an other scale?

The result:

but it should be this:

It's a small part, should be a wedge for a connection of a GT2-Belt - width is about 7mm.

Any ideas?

I'll also try to print one with the mentioned suggestions (Temp. reduction, without retraction, lower print speed).

[the_mechanical 0]

Only a little bit better with decreasing Temp. from 200 to 195, changing print speed from 60mm/s to 30mm/s, no retraction.

[owen 19]

Only a little bit better with decreasing Temp. from 200 to 195, changing print speed from 60mm/s to 30mm/s, no retraction.

 

try printing 2 at once and use 100% fan

[Torgeir 228]

Hi Paul,

Try printing without using the heat bed, use only glue.

I've had som issues like this when printing small object at lo height and using heat bed.

Use extruder temp 192 -195 deg. C.

Thanks.

Torgeir.

[the_mechanical 0]

Hi owen,

much better with more parts. Still not perfect, but in a way that at least it seems to be easy to remove ;-)

Thx

[MaxPower 4]

Hi everybody,

I had similar Problems with blobs especially with thicker nozzles.

Mine came from not perfect retraction settings.

I changed to Simplify 3D as new slicer (very nice but 150$, definitely worth it if you print a lot)

I used mainly two options:

coasting- stops extruding about 1...2mm before end of line, but some filament keeps on coming out of the nozzle

Extra restart distance about -1mm so the extruder retracts in my case 4,5mm and restarts with only 3,5mm.

The first minimizes a blob am the end of the line, the other alt the start of the new one.

I think there is no possibility to do this in Cura.

I changed to Bondtech extruder and 3D Solex Block, thats I I also changed the Slicer and played with thick nozzles, high speeds and optimal settings.

But before, with my Original UM2 extended, Cura was always doing a good job. The Standard values worked OK.

Maybe that helps.

Cheers,

Ascan