qidi printer having problems with larger prints...larger print considerations?

[codejoy]

I was here in december (man time flies) and got some great advice and manage to churn out a few cool 3d prints (namely some tiles for a board game called catan) worked great! Though I realized something strange then (got busy and haven't picked it up till now) that the larger prints of the borders for the board game were curling up bad on the corners and getting caught on the extruder.

Okay so fastforward to now...I tried to build my first 3d model and print it. it is a simple pinhole camera box based on a design of a checkbook box one I built. So here is the screenshot of the model:

boxprinter.jpg


So i thought it would be a simple print but it is pretty large and I have done 3 attempts:

attempt 1: I used the same settings I have for all my catan tiles 60degre print bed, 195c pla temp and slow speeds. no raft. It curled the corners up and twisted the main thing but it did 'print' though the bottom had divits in it (the part thats on the print bed). Also the left corner curled way up and i stopped it as it was printing the first wall on the bottom piece there (the top part). Are there more considerations with larger prints? Print speeds are slow still and I have the shells set to 3, roof and floor thickness to .90mm and the layer and infill heights to .20mm

I read around on the internet and saw maybe the print bed was not evenly heated and too cold and so I upped the temp to 64c .... no curling but the second print failed because I must of whacked the print bed out of alignment left side printed right side started to drag into print bed so I stopped it right away. Releveled.

Then a few other prints it just was a gunky mess...and not sticking any part down. Thought it was a glue stick issue so i tried more of that and that didnt help really...

Trying one where i am using a raft, that seems to be okay but its curling up on the corner and the edge (the raft) and i dont have much space from raft edge to edge of the other thing. plus the floors it slaying down are divited looking too...not stringy but not its normal greatness.

so stopping this latest print and coming to here the forums to ask what else I should look at? I built the model with tinker cad and its about 150+mm by 88mm by 60mm high. Not sure what the important factors to look at and try here. I am guessing the curling is a cooling issue but then I think the latest build with the raft and all that is because my print bed temp is still 64 c and its *too* hot?


So some pics of the first print and the most recent one im cancling too thats at 195c extruder, print bed 64c....
travel speed 150mm/s z-axis travel speed 23mm/s minimum layer duration 4.0s

and the rest of the settings here:
shells 3 roof floor thickness .90mm layer height .20mm
Speeds first layer 15, first layer raft 15mm/s infill 45mm/s outlines 20mm/s, raft 45mm/s raft base 25 mm/s
infill 20%
infill layer height .20mm

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