File type for 3d printing

[Newlands]

Been meaning to ask this for a while - what file type is the most useful - step, stl or 3mf?
I use Fusion, and have an Ender 3 and a Bambu. Most of the things I make are what I draw up in Fusion, but I'm not averse to using things from Thingiverse etc. And one major annoyance with downloaded models is that they are difficult or impossible to do anything with other than print them as they are - maybe that's just me being dim!

 

[ajlelectronics]

Been meaning to ask this for a while - what file type is the most useful - step, stl or 3mf?
I use Fusion, and have an Ender 3 and a Bambu. Most of the things I make are what I draw up in Fusion, but I'm not averse to using things from Thingiverse etc. And one major annoyance with downloaded models is that they are difficult or impossible to do anything with other than print them as they are - maybe that's just me being dim!

.stl is the traditional standard for presenting to a slicer. I keep a Fusion file and the .stl for a part.

 

[clift_d]

You can Insert STL files into Fusion as a Mesh but even a moderately simple file will have hundreds of thousands of facets, and it will be a surface only, as a consequence of the way that STL files save data. The imported Mesh will generally need to be Reduced (simplified) and Converted (turned into a solid) before it can be used.

 

[Newlands]

You can Insert STL files into Fusion as a Mesh but even a moderately simple file will have hundreds of thousands of facets, and it will be a surface only, as a consequence of the way that STL files save data. The imported Mesh will generally need to be Reduced (simplified) and Converted (turned into a solid) before it can be used.

That's useful, thanks. I was right about being dim - I didn't know about the Mesh toolbar option. One strange thing is that an stl file seems to import at around 10x the model size - easy enough to scale of course but I don't understand why it works like this, maybe a setting I have yet to discover.

 

[Agroshield]

Please read through this thread, particularly the contributions from Dr Al (starting at post #3). He outlines the various file formats and features thereof:

Beginners guide to 3D printing

I can weld a bit, bash tin and I haven't yet seriously injured myself with a machine tool. I know the cube root of FA about 3D printing. Please enlighten me. I can draw things using paper, pencils and pens, but have never used CAD in anger, so I guess that's the starting point. I have a...

www.mig-welding.co.uk

 

[Dr.Al]

If you want the short answer to your question: STEP. Only use an STL if your slicer can't do STEP (but in that case, you should still save a STEP file). Prusaslicer and Bambu Slicer both support STEP files.

If you need to edit a downloaded STL then Tinkercad is quite a good option (or use the editing tools that are present in some slicers). Some CAD software makes it relatively straightforward to reverse-engineer simple STLs, but life is so much easier with STEP files (and it gives you a safe backup of your design so you can edit it later).

As I said, if you use a slicer that doesn't support STEP, then save a STEP and an STL.

This video is quite good for explaining how to reverse-engineer a simple STL (in Solidworks, but the principle should be similar in other tools) if you absolutely have to (by contrast, if it were a STEP file, it would have just been a case of opening it and starting to make the required modifications):

 

[Newlands]

As I said, if you use a slicer that doesn't support STEP, then save a STEP and an STL

Yes - I've just read through the thread that @Agroshield recommended and understand the reasoning much more clearly. I've also been playing with step and stl files in Fusion in the last half hour, following @clift_d 's comment, and its all a bit clearer now. I think I've just been too lazy to really get my head round it - knock something up in Fusion, export it and then slice/print to get the job done, without thinking about it too deeply.
I might have to have a look at Tinkercad as everyone seems to think it's pretty good, but Fusion works fine for me (I have used it for cnc router stuff for some time). Exporting everything as a step file is obviously a good plan though, who knows when Autodesk will pull the plug on the free version, or cripple it beyond use.

 

[Dr.Al]

Yes - I've just read through the thread that @Agroshield recommended and understand the reasoning much more clearly. I've also been playing with step and stl files in Fusion in the last half hour, following @clift_d 's comment, and its all a bit clearer now. I think I've just been too lazy to really get my head round it - knock something up in Fusion, export it and then slice/print to get the job done, without thinking about it too deeply.
I might have to have a look at Tinkercad as everyone seems to think it's pretty good, but Fusion works fine for me (I have used it for cnc router stuff for some time). Exporting everything as a step file is obviously a good plan though, who knows when Autodesk will pull the plug on the free version, or cripple it beyond use.

Fusion is much better than Tinkercad. Tinkercad is good if you need to tweak an STL as it's a triangle-modelling package, so it works directly with STLs. For general modelling though, Fusion is better. You've read the other post, so you'll know that I think Fusion is much worse than a lot of other CAD options (Onshape, Solid Edge, Solidworks Makers / Education Edition etc), but if it's Fusion or Tinkercad, stick with Fusion.

 

[Newlands]

Just to add to the mix, it looks as though the Bambu Labs slicer only likes 3mf files - File.. Open.. shows the other file types as greyed out. So it looks as though I'll be saving the native Fusion file, and exporting as stl, step and 3mf.
I'm still playing with the Bambu printer as I've only had it a few days - I knocked up a pen holder in Fusion which will hopefully fit the Gridfinity system. The speed compared to the Ender 3 is quite impressive - 19 minutes for this, 42x42x30mm in PLA:

 

[Agroshield]

This seems like a good introduction to how the file types differ:

Decoding 3D Printing Files: .step, .stl, and .3mf Explained — 3D People UK

Dive into the world of 3D printing file formats. Explore the advantages and limitations of .step, .stl, and .3mf, and how our updated Online Quote Tool simplifies your design-to-manufacturing journey.

www.3dpeople.uk

STL is kind of the lowest common denominator, at the bottom of the tree. A 3MF file contains everything an STL contains and some more. A STEP file is top of the tree.

Reading around, internet wisdom suggests that STLs have to be imported into Bambu, which is different to opening them.

 

[Dr.Al]

Just to add to the mix, it looks as though the Bambu Labs slicer only likes 3mf files - File.. Open.. shows the other file types as greyed out.

I find that quite hard to believe. Is it possible that the File...Open... command is opening Bambu projects (which would be saved as 3MF typically) but that there's a File...Import or similar that can read STEP / STL? Failing that, have you tried just dragging a STEP file from Windows Explorer and dropping it on the Bambu Slicer window?

 

[Newlands]

Oh yes, of course it imports all of them, and I should have known that. Still getting used to a slicer that looks like it wasn't produced by Fisher-Price!
Anyway, from Fusion to reality in about half an hour: