My Ultimaker eats boogers!

[LesHall 95]

...well, the prints eat their own boogers. By this I mean that the gob of initial filament that the printer nozzle spits out in the front left corner of the bed at the beginning of the print often gets pulled into the print itself. It often gets "eaten" into the print and resides in the spaces between the infill traces. What's the fix for that?

Les

[geert_2 556]

For an UM2 (non-plus) try this:

This wipes the nozzle after priming, so it does not drag the priming blob around anymore. I plied it out of inox spring steel wire (1mm), after an idea from another user who made it first in plastic (search for "filcatch" or something). The advantage of metal is that it does not melt, obviously. The spring steel makes that the nozzle easily slides over it, without causing damage. It just gives a nice ping sound. It has been in use succesfully for about 1.5 years I think, I haven't had any problem since.

I don't know if you can use the same idea on other models (UMO, UM2+, UM3), because they might have different priming positions or starting routines.

[LesHall 95]

geert_2,

This is, to me, an ingenious solution! I was expecting a software approach in which the nozzle is lowered earlier so the boogers stick to an untouched area of the bed and don't get tangled up in the print. Maybe both is best. Can you sketch the shape of your wire clip as I don't quite visualize it yet?

Les

[cloakfiend 994]

I think this happened to me once and I just grab it for fun now every time I print. It has become a nozzle check routine for me as I don't bother with atomic pulls anymore. I am always looking at the first few seconds of my print for any levelling issues anyway... so if I don't get the blob tower or it doesn't stay there (as in your case) that says to me I have a problem with the flow of my filament. That wire business to me is total overkill and ignoring the problem, which I imagine is flow. I could be totally wrong though but if the filament does not fall fast enough and stick to the plate it's a warning sign for me that something is up. I always hope for a neat cone pile before a print! No cone makes me worried! I would normally do atomic pulls if I was concerned but unless you print hot or have burn issues or need instant colour changes I think atomic pulls are also a waste of time now.... I've become very casual about printing lately!

[nzo 16]

I use a UM2+ and my solution is to wait for that special moment when the extruder finishes its filament dump and grab it with some surgical tweezers. I have to pay attention, otherwise I miss the magic moment and the dump gets dragged into the first layer. But I'm pretty good

Edited November 23, 2017 by Guest

[LesHall 95]

OK so what I'm reading here is that instead of my 3D printer eating it's boogers, I can grab the dump that it makes prior to printing each batch? That or an automatic booger wiper, or checking the flow?

Too much, way too funny.

Les

[geert_2 556]

Here you have it, seen from both sides. One is from the first printer, the other from the second. Basically, it is just plied steel wire (inox spring steel, as used in dental appliances), so that it clamps around the edge of the frame. It looks primitive (well, it *is* primitive), but it works fine for me since 1.5 years.

At first I also grabbed the priming blob with tweezers. But sometimes I forgot or I was too late, when doing something else inbetween the warming up.

The reason why this priming blob does not stick to the glass, is that the purging is done from some height, at least on my UM2 (non-plus), so it cools down too much and is not squeezed into the glass.

[cloakfiend 994]

Just grab it...its more fun! and you dont need to bang your nozzle into anything which seems a bad thing to do anyway. I grab it after regardless as mine doesnt drag the pile but i like grabbing it anyway!

[LesHall 95]

I forgot to mention that the nozzle I'm using is 0.8mm diameter so it leaves a cold booger dripping every time it finishes a print job. This prevents the filament from properly forming a blob at the beginning of a print.

[cloakfiend 994]

Ahhh. I have no experience with 0.8mm nozzles... No OB anymore so 0.4 for life!