Prusa Slicer can not handle helix ?  

The slicer can handle helixes - or we'd never print a screw thread ...

Please save your project as a .3mf file

Files > Save Project as

Zip the .3mf and post it here. It will contain both your part and your settings for us to diagnose.

Cheerio,

RE: Prusa Slicer can not handle helix ?

Hard for OP to upload a 3mf file if s/he can't even load the step file 🙂 

Have you tried to export the helix as an STL file from FreeCAD and import that? I don't usually import STEP files so I don't know if PS has any limitations in that area. Whenever I tried it, it worked.

RE: Prusa Slicer can not handle helix ?

The OP has been working all day, for which he humbly apologizes, especially to mr. Fuchs 😎 

But the tip was a good one: export to .STL worked, so did export to .3MF. I did a re-export to .STEP, just to check my sanity, but that still brought Prusa Slicer to a standstill. 

Here's the .3MF.

RE: Prusa Slicer can not handle helix ?

... and here is the original FreeCAD file

RE: Prusa Slicer can not handle helix ?

That 3mf loads in Prusaslicer and slices just fine for me. Sorry I know that's not tremendously helpful.

RE: Prusa Slicer can not handle helix ?

Posted by: @fablabwag

... and here is the original FreeCAD file

 7c0a1c85-helix_experiment_4a.zip

I fired up your model in FreeCAD v1.0.2 (current stable) and exported two ways. One as just the Body, and the other as the Part. I was able to load both into PrusaSlicer by dragging and dropping the files into the PS window. Note, both seemed to freeze the program during a couple minute import. I didn't time either import so I don't know exactly how long. All I know is it seemed to be taking a while so I did something else for some minutes and when I came back they were loaded. Here is a screenshot of PrusaSlicer v2.9.4 with both models loaded. The green one (named Helix_experiment_4a-PartBody.step) was the export with only the body selected. During the import, I selected "Medium" quality (really, the default that I have never chosen to change).

For reference, here are my computer specs (maybe you didn't wait long enough if your have a similarly or lower spec'd computer):

• Processor Intel(R) Core(TM) Ultra 7 165U (1.70 GHz)
• RAM 32.0 GB (31.4 GB usable)
• Windows 11 Enterprise Version 25H2 (work laptop)

Here are the 3 files I generated, the two step files and the 3mf project with the two step files imported.

Helix_experiment_4a-StepImport

RE: Prusa Slicer can not handle helix ?

sorry Geoff,

I did not make myself clear, probably. Export to .3mf AND opening in Prusa Slicer worked, as with .stl. But exporting to .step (still) not. So it seems it is not the helix sec that is the issue but the transformation to (through ?) .step. I realize I better attach the . step file ...

RE: Prusa Slicer can not handle helix ?

Thanks for trying out, Sembazuru.

My desktop has definitely lower specs than your laptop. So this seems a hardware issue. In my situation, Prusa Slicer seems to freeze to death (message 'program is not responding') but thanks to FoxRun's tips I now know that there is a good working alternative in using .3mf or .stl .

RE:

I think it's a question of memory - or a bug.

The problem shows for me, too: Loaded the freeCad file, exported as .step, imported into PrusaSlicer.

26 GB memory consumption and it's starting to chew into the swap file. Not necessarily a bug - rendering this geometry with (probably generally reasonable) default tolerances may just require more computing horsepower than what I've got on my desk. 

RE: Prusa Slicer can not handle helix ?

... took more patience than the forum's edit window but the job completed. 

PrusaSlicer chews through DIMMS like cookies but completes eventually. The exported .3mf file is 8 MB so yes, memory usage seems a bit excessive.

But hey, memory is cheap nowadays (coughs...)

RE: Prusa Slicer can not handle helix ?

Ouch. That hurts.

I have a humble 16GB, which until recently was enough for conquering the entire universe... My 2 slots are full and replacing by 2 x 16GB costs a small fortune - make that a large one 😭 .

My mindset was: "It's a single citcle with a helix, how hard can that be ?" I better reconsider, I think.

I's almost certain to be a case of trading accuracy for resource usage.

Only you can judge your requirements but it is not unknown for a user to specify a part to a degree of precision much finer than an extruder could ever squidge plastic and consequently to generate a huge gcode file of miniscule steps when a much smaller, faster, and yes, less precise file would suffice.

Cheerio,