Start of skirt curling

Hi,

This is my first post, I've looked for similar questions and can't find anything specifically addressing this issue, but if I missed something and this is an obvious question, apologies.

I've just completed my build of the hephestos Prusa i3 and I'm now in the calibration and fettling phase, which I'm quite enjoying.

I have some issue with adhesion of the first layer, which I'm going looking at, but there seems to be plenty of info online about this. However one issue I'm getting is that the very first piece of extruded material, maybe first 10-20mm curls up a lot, almost vertical. this then catches on the print head on the following pass, and then dislodges the whole first layer.

I've been working around this by printing a large skirt, say 50mm out, this gives me time to get a pair of scissors in and snip off the curled up bit. The print then continues successfully (well at least until the first layer warps, pops off and collides with the head, but that's the 'standard' adhesion problem I think).

Any one any idea why this very marked curling at the very start of extrusion?

Thanks.

The larger surface area, the bigger the amount of shrinkage the plastic will have over it's size. Did you try anything in-between no skirt and a huge skirt?

I think there the main problem is the adhesion. This can be caused by print bed temperature and initial low adhesive qualities of the surface. Distance from nozzle to print bed also needs to be optimal for good adhesion.

Solving the initial problem will also make it so that you don't have to counter the effects of the issue with a huge skirt.

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http://www.marinusdebeer.nl/

I maybe using the wrong terminology here; by skirt I mean a thin border extruded around the object, and then a gap (~50mm) between that and the start of the object. The skirt doesn't actually connect to the object at all, and is only a few mill wide.

I guess my questions boils down to: if I sort the overall adhesion issue is that likely to fix the curled up start issue aswell, or is the curling start a separate problem?

Ah! You are right, I was confused between skirt and brim.

But, still, fixing the adhesion will fix the skirt. I had the same problem with both ABS and PLA and both of the issues on two different printers had to do with incorrect bed leveling, print temp, heated bed temp and the kapton not being clean enough.

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http://www.marinusdebeer.nl/

So, after covering my bed with blue tape and RE levelling, the adhesion issue is sorted, and so is the initial curling problem. One happy printer here now.

Quote
Sijomon
So, after covering my bed with blue tape and RE levelling, the adhesion issue is sorted, and so is the initial curling problem. One happy printer here now.

Yes! That's good to hear

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http://www.marinusdebeer.nl/

If you tried applying kapton tape & re-leveling the print bed and it is still not working.

There is a good chance it is related to the print bed temperature.
If you are working with ABS, the ideal print bed temperature is around 100C.
As for PLA i prefer around 55C.
Both of them is printing without a cooling fan.

If you are using a cool fan,
ABS: 110C
PLA: 65C

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