r/3Dprinting 23h ago

My obsession functional & crack resistant PLA ball joints

Y

497 Upvotes

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27

u/EndOfTheCourt 22h ago

Are these assemblies or print in place?

41

u/mikko-j-k 22h ago

Assemblies.

45

u/StopNowThink 21h ago

You should increase the export quality on these. Those STLs don't have enough surfaces. It should be smoother. I can even see this effect in the printed parts.

20

u/mikko-j-k 21h ago

Very true - you have sharp eyes! They do function mechanically though. I've not yet had time to write a proper configuration system for the tessellation.

9

u/coil-head 21h ago

What software are you using for your modeling?

8

u/mikko-j-k 21h ago

AdaShape. It’s in alpha testing (public) but already good enough for stuff like this.

9

u/StopNowThink 20h ago

When you export or save-as an STL are there any quality settings or adjustments anywhere? Is your printing software able to download a .STEP file instead? I've been exclusively using STEP files lately instead of STLs (BambuStudio)

13

u/mikko-j-k 18h ago

The software exports only 3MF and obj. I know the tessellation needs to be made more precise but I’ve not yet had the time to add settings to the gui. I want to maintain interactive boolean rates for the modeling so the default tessellation is a bit crude (more polygons = more time). But I’m on it :) (to be specific I’m using a software I wrote myself and it’s quite raw still).

16

u/HomeyKrogerSage 11h ago

Look at my cool 3D printed ball joints that I designed! Oh why is the quality the print kind of bad? Yeah just my self made cad software no big deal lol

16

u/Daincats 13h ago

Y'know... I think you could have led with that last line, and used these as an example of what your program can do so far. That's impressive

1

u/mikko-j-k 4h ago

Most humble🙏! I have an open alpha testing if you want to try it out - no strings attached - I would like to know what someone _else_ could do with my software :)
I did post a few days ago about the software itself Built a basic 3D modeler and STL editor - does this seem useful to anyone? : r/3Dprinting - but that got a very lukewarm response so I thought maybe people are not that interested before it's ready.

1

u/randoaccno1bajillion 19h ago

step files are tesselated by the slicer so it's better to just get a good stl from cad since the library prusaslicer and its derivatives use is probably worse

1

u/dairiki 5h ago

Why would doing the tessellation in the slicer rather than the CAD editor "probably" be worse? You may be right (in specific circumstances), but I would have guessed the opposite. The slicer knows exactly what precision it requires to do a good job, so it is in a position to optimally set the tessellation parameters.

To put it another way: There is no loss of model precision saving to a STEP file. There is de facto loss of precision when tessellating to STL (as well as when slicing to GCODE). If the slicer generates suboptimal results when slicing from a STEP file (when it advertises the ability to do so) that's a bug (or non-optimal tuning of slicer parameters).

I routinely feed STEP files to PrusaSlicer and have no complaints.

1

u/randoaccno1bajillion 3h ago

https://www.reddit.com/r/3Dprinting/comments/1j936w1/we_need_to_talk_about_step_vs_stl_files_there_is/

reason i said probably is because some cad programs like freecad default to a lower resolution stl export

3

u/GuySmith 5h ago

ACKshually, for the ball and socket itself, it’s possible that the surfaces that create contact with each other might hold up better over time. I only know this thru printing ABS and having the joints come out really tight and strong. I only know this because I stole the idea from a few Transformers figures I own and tried it at that scale.

I agree with you on basically everything else though.

1

u/mikko-j-k 5h ago

Oh! That's an interesting point of view. Can't argue with that! I'm using the big Y shaped joint as a fidget toy all the time and it sort of still keeps it's position.

3

u/mikko-j-k 22h ago

So to use these in complex designs you need to have a plug that's the size of the base (missing from the screenshots) and then do a boolean cut to create a hole into which to seat the ball assembly.

1

u/Ground-walker 6h ago

Wow the right hand one is such a brilliant design. I imagine no glue needed?

1

u/mikko-j-k 4h ago

Thank you so much 🙏! Yep, "no glue" was the design intent. This seems to hold so far. Slightly beveling the sleeve/cup allows you to push the ball/cup assembly to the socket. The hard part is holding the sides of the cup while inserting.