Importing stl to luban

Very new user here.
I’ve created several stl files from scratch - meaning I type them in text on Notepad. Some of these I can drag into Luban and then generate g-code and then print. Others - all the ones I’ve done in the last few attempts - just generate the following message: “Failed to import this object. Please select a supported file format.” When I compare properties of the ones that work with the ones that don’t, I can not find any difference.

I can’t say that I’ve written STL files by hand. All the ones I’ve looked at appear to be some binary format that includes a lot of unprintable characters: NUL, BEL, and various 8bit characters. Reading the description of the file format, that seems like something I’d be more inclined to write a C program to generate than input by hand.

Can you upload some examples? As a new user, you’re limited. According to @JKC20 ,

The default setting for promoting to the next tier from a new user on a Discourse forum is enter 5 topics, read 30 posts, and read posts for 10 minutes.

Once you do that, you should be able to upload at least one file.

Thanks for the response - Here is one of the files that could not be imported into Luban. Note that it can be opened in Notepad. It worked in CURA and even successfully printed on a non-snapmaker 3d printer.
By the way - when I said “write by hand” I meant I was using stl text format. I generated much of the file through the use of the program SAGE. I did write some simpler stl files completely by hand - that only had around 20 or less facets.

4TallPillars.stl (45.4 KB)

The object was not manifold i.e. not printable for one of a few reasons. See this

I opened it with Repetier Host, an app which is able to fix problems like that and then exported it again.

Try this file:
4TallPillarsFixed.stl (40.2 KB)

Thank You!
I’m still a little confused. “Your model is not manifold” was not the error I was getting.
In terms of getting it printed, I did find another solution since I posted yesterday - which was to take a file that Luban was reading and paste my text into that file and then delete the original contents of that file.
So - I got around the problem, but still don’t know what caused the problem - or even exactly what the problem was.

This is what it looked like in Repetier-Host:

Looks like some of the facets were self intersecting… maybe.

Yes, this image does show that there could be problems with one or more of the pillars.
But I get the same error message for several different files - all of which open in Cura - and then slice and print successfully also (on the non-snapmaker machines).

Another “solution” that has worked on some new files - the files that won’t load in luban will load in blender. Then without any modifications, I can export as an stl file, which is then recognized by luban.

Luban uses the Cura engine, but doesn’t make all of the settings available. It’s typically the current engine upon release, but it could be a few releases behind that.