Luban hanging on large STL files

Now that I have my printer printing large prints well I’ve run into a different issue. I’m trying to print this kickstarter: Leichheim, A 3D printable Medieval Metropolis (STL) by 3DLayeredScenery — Kickstarter

The buildings are quite large prints and when I try to slice them in Luban it starts, then just hangs. I’ve even let it run overnight and it makes no progress. It uses no CPU.

All slice fine in Cura. They take ~5 minutes to slice, but they do slice. No errors in them either.

Yesterday I updated to the latest build to see if that helped, but it has the same issues.


Please write the stl size in your post and reach out to or @parachvte

The STLs are 110KB, 129KB and 172KB in size.

This is not a big file, i wonder about.

RC Felge_Raphi_V14.stl (1.6 MB)

Try this file with high settings and a scale of 500%, my pc took about 1 min to slice, generate and preview gcode.
8x 3,9Ghz 32GB RAM WIN10 latest

Have a look at this thread, which shows your 300kB stl size should be peanuts:

I agree it shouldn’t be an issue, but it is. Luban never finishes while Cura has no problems.

Luban just hangs, CPU drops to 0% and it just stays there.

This (500%) slices and previews fine in about 10 seconds.


I debugged it a bit more.

It hangs after “preparing for slicing…”, but before the “slicing engine for Cura” process starts. When this process doesn’t start it just hangs forever and I have to kill it from the task manager.

I have had it successfully slice a model, then hang on other attempts. So I don’t think it is the model.

500% with high quality?- wow.

Share your stl for a few test´s via pm pls!

sorry for high quality it took about 30s

Ähm, the file you provided has 168MB, not kB as mentioned in your previous post.
Now things get clearer.

I have tried your stl and get no results with fast print quality. It seems Luban can´t use or organize more tha 6GB Ram.

oops I miss the 169,000KB sorry

Ive just upgraded the luban software to 3.13.1 and now seem to be running into the 6Gb memory limitation which causes the task to hang indefinitely.

Can anybody confirm that this a new bug and if so should I revert to an earler version. Is this possible?

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I had the same problem an the earlier version 3.10? I think. I upgraded to 3.13 in the hope it would be resolved. It wasn’t.

I have found that I can get some of mine to print by the following.

open Luban, remove all STL and gcode models.
restart luban; it should be completely empty.
load STL

I’ve found that often this will allow me to stay under the 6GB limit and slice. But I also have other STLs that hit 8GB slicing and this doesn’t help.


Ive tried an earlier version of Luban with no sucess…

but cant say i understand exactly how to check if the model is under 6Gb !

Is there any documentation?

One thing that is still unclear is whether the file type is significant.

For instance I can load generate gcode for a stl file of 97.2 MB (101,997,684 bytes) but not with obj files that are much smaller.

…in otherwords are obj files more likely to fail

or is there a file verification program that will check for format errors,?

ps shouldnt there be a cancel operation during slicing / previewing ?

I don’t know how to tell either. I just watch the Luban process in the task manager. Or if the slicing window goes blank, I know it hung and kill it.

Was there any updates for this? I am having the same problems in High Quality with a 153mb file.

Hi Everyone,
I have the same problem, my STL file is about 650mb and the app hangs


I have the same problem, stop at 15% with large STL files.

any Solution ?

Thank you

I have a 9MB STL (but I’m duplicating it) and it seems to hang at 30%. “Previewing G-Code” is the message it’s stuck at. I just recently installed Cura and it seems to work okay with it, but I’d rather use Luban because that’s what I’m used to and it looks like Cura requires a bit more setup.

I recently updated to Luban 4.12.0. I’ve definitely printed larger things in the past, so I’m guessing the issue is with the latest update.

Hm. Tried with 4.11.0 as well and it still does the same thing. Even with just one copy of the STL. The STL also requires repairing. I’ve tried it both with and without repair and the same issue.

I’m trying to print Base.stl from this item on Thingiverse (I can’t attach it here since it’s larger than 8 MB).

filament dry box by tkostandyan5 - Thingiverse