This is TPU, how do you think it got made?

50 views
Skip to first unread message

Randy Zimmer

unread,
Aug 11, 2026, 10:26:57 PM (5 days ago) Aug 11
to 3D Printing Tips and Tricks
cropped.jpeg

Kurt The 3D Printer GUY!!

unread,
Aug 12, 2026, 7:16:14 AM (4 days ago) Aug 12
to 3D Printing Tips and Tricks
Large nozzle - maybe 0.8mm - slow print head movement - slowly extruding - nozzle at 200mm above bed - then random motion of print head OR - maybe it's truly like and angular grid pattern draw. 

Am I close???

-K

On Tuesday, August 11, 2026 at 10:26:57 PM UTC-4 Randy Zimmer wrote:
cropped.jpeg

Randy Zimmer

unread,
Aug 12, 2026, 8:18:24 AM (4 days ago) Aug 12
to 3D Printing Tips and Tricks
I have no idea. I'm used to striving for precision and then was asked to duplicate chaos. I like the nozzle and distance but I have no idea how to program random motion. I've goofed up a lot of prints but never got something like this since my first extruder test - that was a real bird's nest.

Owen Collins

unread,
Aug 12, 2026, 9:13:07 AM (4 days ago) Aug 12
to Randy Zimmer, 3D Printing Tips and Tricks
I remember once on thingiverse a helluva long time ago there was a Snowflake generator, that created G-code to put in Rep-G. Each output of the generator created different snowflake. 

SO maybe you need a script to create a random path for each layer, then it would start to have more of that visual chaos…

But as a theater guy, I wouldn’t know how to make that script.

O.

-- 
You received this message because you are subscribed to the Google Groups "3D Printing Tips and Tricks" group.
To unsubscribe from this group and stop receiving emails from it, send an email to 3d-printing-tips--...@googlegroups.com.
To view this discussion visit https://groups.google.com/d/msgid/3d-printing-tips--tricks/cd264670-2d8b-478a-b4d8-7eac4477937cn%40googlegroups.com.

Kurt

unread,
Aug 12, 2026, 12:04:59 PM (4 days ago) Aug 12
to 3D Printing Tips and Tricks
SHOOT! I was Wondering why this response of mine was NOT showing up in the Forum - then I saw I sent it ONLY to Randy! 

DOH!!!!

Now EVERYONE can Enjoy this reply...

-K

---------- Forwarded message ---------
From: Kurt <kurt.the...@gmail.com>
Date: Wed, Aug 12, 2026 at 11:59 AM
Subject: Re: This is TPU, how do you think it got made?
To: Randy Zimmer <randyz...@gmail.com>


So - where did you get that pic? Was it REALLY TPU that we are looking at?

At Essentium - I used to have fun doing something like this - just dropping the bed - manually control the printer to heat up the nozzle - then simply moved the print head around while it's extruding!

Now - since you posed this problem - I figured I would play around with it a little. I went into my Elegoo slicer - I created a box that filled most of the build plate. 
image.png

I then and essentially had it NOT Print walls, top or bottom - this was it in the slicer after slicing it:
image.png
I chose Gyroid since I figured THAT would get you closest to the chaos you were seeking. 

So - I worked with Claude to do the Offset. This is what it looks like in the Prusa Previewer - and, yeah, I did the slider to show starting at 2nd level:
image.png

Finally - Claude & the G-code trick:

The setup is a box sliced with gyroid infill only — no top layers, no bottom layers, no perimeters/walls. Just the infill. Turn off skirt and brim too, since nothing is going to stick to anything. 4–8 layers is plenty — you get the full effect in a few minutes instead of committing hours to it.


Then the actual trick: you shift the entire print up into the air so the nozzle never touches the bed. The extrudate leaves the nozzle with nothing to land on, sags and curls on the way down, and each pass lands on the tangle below instead of a flat surface. TPU is the right material because it stays rubbery and coils instead of snapping.


The two lines to insert:

G1 Z25 F600 ; lift nozzle 25mm above the bed
G92 Z0 ; call this new height Z0

After G92 Z0, every Z the slicer emits is read relative to the raised position, so the whole print floats. Nothing else in the file needs editing.


Where to put them — this matters more than the lines themselves. They go at the very end of your start G-code, immediately before the first layer. Specifically:

  • After the last G28 (homing resets the coordinate system and wipes your G92)
  • After any G29 / M420 S1 bed mesh line
  • After the prime/purge line — you want that drawn normally on the bed so the nozzle is loaded and pressure is up before the chaos starts
  • Before the first ;LAYER:0 / first model extrusion


In my file (and I am attaching the final GCode file to this posting response) that landed right after the G92 E0 ;Reset Extruder that follows the purge, and just before the ;LAYER:0 block. Then Ctrl-F the rest of the file for any later G28 or G29 — if your slicer emits one mid-print, the nozzle drops back onto the bed and the effect is over.


Part cooling: run the fan at 100% from the very first layer. The strands have to freeze in mid-air. Check your slicer for "disable fan for first N layers" or a reduced first-layer fan speed and override it — mine had the fan off for all of layer 1 and only ramping to full at the layer 1→2 change, which would have dumped the first pass down as goo.


Height is the tuning knob. 25mm is a good starting point. Lower (5–10mm) gives tighter, more matted tangles; higher gives longer free-fall and looser, loopier strands.

One heads-up: your G-code viewer will show a perfect gyroid lattice floating in space, because it draws where the nozzle travels and has no physics. The file and the result are supposed to look nothing alike — the chaos only exists at print time.


-K


--
Chaos_Cube_TPU_6h_V2.gcode

Bryan Eckert

unread,
Aug 12, 2026, 1:37:49 PM (4 days ago) Aug 12
to Kurt, 3D Printing Tips and Tricks

Kurt

unread,
Aug 12, 2026, 1:52:43 PM (4 days ago) Aug 12
to 3D Printing Tips and Tricks
OK Bryan - I know you're being funny (after watching that quick video) - just like you were being funny in your last reply re:LightMake. 

But, there is a faster way to do this. You make a Simple small like cylinder - and then make the box design floating in the air above it. But, you have to do this in a 3D Modeler - I just go NOT do it with the tools I had hear at work - and thus figured out the solution using ONLY a Slicer - creating the basic box - and then those settings. I just knew that one could insert 1 or 2 lines of code directly into GCode to get things to work the way I wanted it to - thus why I used Claude for that part only...

But - I'm Totally Excited to see what Mr. Zimmer is able to do!!!

-K

Kurt The 3D Printer GUY!!

unread,
Aug 12, 2026, 8:21:20 PM (4 days ago) Aug 12
to 3D Printing Tips and Tricks
Randy - you READY For this???

I went so far as to do a TEST Print - but, I did it Differently!

Attached is the STL I printed - and, yeah - No Walls, Top, Bottom - and I used Hildebrand type Infill. This is the pic of the print (you can see the Circle) - Yes - although printed in PCTG - you could do similar with TPU - and, yeah - Slowed the printing down - but, to do it RIGHT - you need to slow it WAY DOWN!!!!!!!!!!!:
Chaos Test.jpeg
Chaos Test.stl

Randy Zimmer

unread,
Aug 12, 2026, 8:53:07 PM (4 days ago) Aug 12
to 3D Printing Tips and Tricks
Yes Kurt, it looks really promising. 
I use S3D and it has a big selection of infills. 
I'll start with stars, that should make some wild bends.
I had a fire in the shop and all my stuff that still exists is in a warehouse somewhere or I'd be doing tests already.
The final shape (outline) that she wants may be best done by making a "cookie cutter" and trimming away the excess perimeter squiggles.
The part won't be a pot scrubber but not far from it.
Thanks for all the help and ideas.
rz 

Kurt The 3D Printer GUY!!

unread,
Aug 12, 2026, 9:32:21 PM (4 days ago) Aug 12
to 3D Printing Tips and Tricks
I'm glad you liked what you saw. But, I'm not CLOSE to what you were seeking - but, I COULD Get Closer!

Can you reveal any MORE Details of the project - and what She wants???

Cause - yeah - I'm curious...

Curiouser and curiouser...

-K
Reply all
Reply to author
Forward
0 new messages