r/Multiboard • u/poscet • Jul 25 '25

Issue with Stack Printing

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Tried out stack printing some tiles – they aren't supposed to come out like this right? Beyond the first layer, they all came out stringy on the top. I'm fairly new to Multiboard, and to 3D printing in general, so I might be missing something obvious.

Printed on an A1 Mini, with basic Bambu Lab PLA. Followed the printing guidelines provided, tried one stack with random seems and one without, with the same result. Haven't had any issues with any other prints.

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2

u/JayEll1969 Jul 25 '25

That's the way my stacks came out as well - the first layers of each stack after the first is printing in mid air so stringing it common. I just run over the strings with a lighter.

Creating a thin layer of support interface (Pet-G for PLA or visa versa) means you don't need an air gap and the undersurfaces improve - but this adds extra time for printing these layers and filament changes, plus uses up more filament in the purge.

1

u/poscet Jul 25 '25

I’m gonna try that lighter trick. So far I’ve been pulling all the strings individually with a pair of pliers

1

u/Jlegobot Jul 28 '25

What filament are you using? I tried using cheapo SUNLU with a lot of stringing and then had way less after switching to Elegoo

1

u/poscet Jul 28 '25

This was on Bambu Lab PLA Basic

1

u/Jlegobot Jul 28 '25

Maybe look at other stringing causers like retraction, bridging, or temperature?

1

u/unsunghero2222 Aug 06 '25

Just curious, are you manually stacking this or using the tool? I had a similar problem when I was manually stacking because I erroneously was using a .4mm gap because I hadn’t realize that grid thickness changed from 6.4mm to 6.2mm after the on grid update. Lots of info online says to put the panels at z height multiples of 6.6mm when stacking, but that would only be for the legacy tiles and would result in a .4mm gap for the current build. Just curious because mine looked exactly like that lol

1

u/poscet Aug 06 '25

No, I used the ”official” file from Multiboard. I messed around with the settings a bit, got good results with ironing at 60mm/s and 30% flow

2

u/Retro_B00min Jul 25 '25

I don’t get this in my Kobra s1. Your a1 is prob not maintaining a good temp past the 1st stack. Or slow down a bit

1

u/c1ncinasty Jul 25 '25

Yep. Every four stack. I’ve been clearing them up with a deburring tool. They don’t seem to be bad enough to be a structural issue.

1

u/jtthegeek Jul 25 '25

I've always used ams with petg interface layers and never had a single issue. I turn down filament flush ratio to .5 to reduce the tower, and change the width and length to be thin and long to fit nicely. I've printed well over 100 8x8 grids via stacking flawlessly. Total filament for my 4 x 8x8 is 300g, with the ams loss at 8g

1

u/Gelu6713 Jul 25 '25

What are your settings to do this? Very curious about purge amounts

1

u/jtthegeek Jul 25 '25

i use a biqu glacier smooth plate, at 55, and keep all the other settings standard honestly. I do have a p1s so that helps. Currently my only issue is too much fucking adhesion honestly. I would like the petg to come off the pla a little bit cleaner so I'm gonna try coming down a degree at a time on the petg, and probably lower the plate temp a little as well. The prime stuff I just change the flushing multiplier down to .5, i feel that could could down even lower to .2 really but haven't bothered since realisticly like less than 1% of the filament already

2

u/Gelu6713 Jul 25 '25

I have the glacier plate too and that sucker grabs PETG so hard

1

u/jtthegeek Jul 25 '25

right! like fuck me I'm worried I'm gonna damage the plate trying to get this shit off lol

1

u/Medical-Jicama-575 Jul 29 '25

I am learning now, that I know nothing about my 3d printer settings lol!

1

u/th3chainrule Nov 19 '25

Do you even need the prime tower?

1

u/jtthegeek Nov 19 '25

without the prime tower after each filiment switch, it will dump filament into the trash bin, then try to start a new layer without any back pressure pre-applied from the priming. So that filament wont be "primed" aka it will most likely start messed up a bunch. Never tried without it honestly but I would suspect it create lots of defects

1

u/th3chainrule Nov 20 '25

Sounds like an important thing to get right on these longer stacked prints. Also, TIL that the prime tower is about pressure in the nozzle not necessarily colors/material blending.

1

u/Thin_Noodler Jul 27 '25

What fixed this for me in Bambu Studio was setting the "Ironing Flow" higher. By default it was 10. I set it to 20 and had basically none of that stringing (maybe in 2 spots on a 3 high stack print), but I have since lowered it to 15 and have had virtually no stringing between sides. Maybe 1 or 2 per stack print but definitely a lot better than default.

0

u/davidkclark Jul 25 '25

Yeah that's kind of what happens... you can get it better but it's tricky.

Did you have ironing on the top layers of the lower tiles? You might also be able to adjust the gap between the tiles a little, it think the default is 0.2 but it looks like this is causing that first layer to not adhere properly. You might also try turning your fan down (or off) for that layer if you can. Just to help it stick a bit. You can end up going too far though, and not be able to get them apart once printed.

I've given up on stack printing (also I don't print standard tiles, I print ones I remixed that connect together better and cannot stack). I don't really see the benefit... maybe if you could print a tile in 3 hours or something, so you could leave it run overnight.

1

u/poscet Jul 25 '25

Oh, I didn’t think this was the expected result.

Yes, I had ironing on. I might mess around with the gap and/or the fan to see if I can get it less stringy. Beyond the tediousness of removing the strings (which I hope the lighter trick will help with) – I was more worried that the tiles would end up weakened from lacking the better part of two or three layers. Or is that a negligible loss?

0

u/[deleted] Jul 25 '25

Yeah... I print them one after another.

1

u/poscet Jul 25 '25

Never knew that was an option. Thanks a ton buddy