Flawed print - is something wrong with my model?

hi everyone, i’ve published a number of my prints, all of which have been of others’ (like from Thingiverse) models - and things have looked really good in most cases. i’ve been teaching myself SolidWorks, and after printing a tutorial print successfully (with only a minor flaw), i printed a simple part that i designed myself. i got an error in PreForm upon importing the STL, and as advised, used netfabb Studio to repair it. the exported, repaired STL (attached) imported into PreForm without issue so I printed it using 100 um layers. as you’ll see in the picture below, there were a number of flaws/cavities in the print - similar to some i observed in two prints of Winterfell, in the wall element.

any ideas as to the cause of the flaws? i’m just wondering if there’s something on my end i can do better or if there’s something in the design that could lead to this. i keep the printer case closed, and try to diligently look for fibers and dried resin in the resin tray. i also printed the strainer part and try to keep things clean that way, and didn’t have any visible bubbles in the resin.

i’m quite the novice so any and all advice is greatly appreciated!

cheers,

-j

first_solo_part_to_print-repaired.stl

Hi Jason,

Could you include a .form file? Seeing how the part is set up for the print can be really helpful in giving feedback.

Craig

hi Craig,

admittedly i neglected to save the .form file this time. so i’ve recreated it here with the same STL, with the same materials and what i believe is the same scaling factor. as before, i printed it without supports given the thickness and flat base.

thanks for any help you can provide!

-jason

first_part.form

Hi Jason, I’d recommend rotating the part by about 30-40 degrees and try printing it with default support structures.

ok thanks! is that to reduce stresses or other factors leading to cavitation or incomplete curing?

Hi everyone,

I’m wondering whether these problems are related in any way to the patent lawsuit that 3DS is threatening Formlabs with?  Is the quality of the resin cure a result of a valiant attempt by Formlabs to avoid using the allegedly protected technology?

Alan

no idea, and i’m not qualified to evaluate the IP potentially at issue. but to be certain, i’m describing infrequent issues on my part, given that nearly all my prints have been great. i’m just trying to understand if it’s my design or the way in which i’m printing it. in any case, i followed Craig’s advice and will have that print done shortly.

i can confirm that re-printing with 30 degree tilt and default supports worked well - no flaws. can you help me understand why this is necessary? i had been assuming (and typically seeing good results) that if the model is completely flat on one side, i could get away with printing without supports (saving time and resin). is that faulty logic?

thanks!

-jason

Hi Jason,

Very often, flat models will print well without supports. In this particular case, there were some holes at the bottom (the center and five countersink holes). These holes can sometime create air pockets, which can lead to voids in the model. The support structures, in this case, created pathways through which the air bubbles could escape.

Craig

Thanks, Craig. This is very helpful!

FWIW my Winterfell model, printed yesterday tilted with supports, is now nearly flawless vs. the one I printed flat and posted pics. I lowered both the density and diameter of the supports with seemingly no noticeable impact.

Cheers,

J

Great news about the Winterfell model. Can you post pictures of the new one?

here you go, Craig! i haven’t done any finishing yet so the support nubs are still visible through the bottom. if you come to my earlier post, the wall is now essentially flawless.

(that should read ‘compare’ to my earlier post]

Beautiful. Someone needs to add a tree into this model / make the rest of the castles!

I’d like to see a King’s Landing…

i believe there’s a derivation on Thingiverse that includes the Godswood :slight_smile: