There will be no more updates to this page. The new home of the Flexi Rex is now on GitHub where you will find the latest updates and where you can download as much as you want even when using an ad blocker.

If you want to sell or give away prints of this model or derivatives of it, and you’re about to ask me something about this: hold it. First read the license clarification part on the GitHub page. Whatever question you are about to ask, is almost certainly answered there, and in that case it’s only waste of time to explicitly ask me the same question and wait for me to give you the same answer.

You do not need to ask me for explicit permission to sell prints. You do not need to share profits. You only need to provide attribution, and what that means is explained on the GitHub page.

Old information now follows. Don’t read this, just go to the GitHub page and read the info there.

This is another remix of Kirbs’ Flexi Rex (Thingiverse thing:1759297), based on airfish’s remix (Thingiverse thing:2189652). That model in turn was most likely inspired by the ‘Flexy Rex’ by zheng3 (Thingiverse thing:929413).

My print of Kirbs’ model was not very kid-proof: one of the links broke after some rough handling. Hence I made all links more robust. This means this model can probably be printed even smaller than the original ones before the links become too weak. Of course you can also scale it up at will.

If you want to create your own flexible model, make sure to check the Hinge Design section below.

Licensing information

See the new GitHub page for detailed instructions about licensing in case you want to sell this or otherwise use this model in a public context.

In a nutshell:

  • This is released under a Creative Commons – Attribution – Share Alike license. Please honor the requirements of that license. You do not need to obtain explicit permission from me if you adhere to the conditions of the license. You can find my interpretation of the license on the GitHub page, and for me it suffices if you follow that interpretation.
  • If you modify this model for non-private purposes, you must publish the modified model file under the same CC-BY-SA license or a stricter license.
  • You do not even need to share profits if you sell prints of this model. Of course you’re always free to use the “Tip designer” button if you want to show some appreciation.

If you’re buying prints of this model from someone: this model contains about 70 cents worth of material when printed in a premium filament. Add to this the costs of electricity and perhaps depreciation of printing infrastructure, and you might end up with $2 at most. Anyone who pays much more than that for a print is being ripped off.

Print Settings

Printer brand:







0.2 mm



Filament brand:

Filament color:


Filament material:



No supports needed. I used 3 perimeters to ensure the hinges are strong, this is much preferred over trying to obtain strength through infill. If you use too high infill, the model may become poorly balanced due to the head being too heavy. If you want to improve stability, use a higher infill for the piece with the legs if you can.

This should move freely right after you take it off the build plate. If you print with hairspray on a glass bed, the Rex may spontaneously jump into a random pose all by itself when it pops off the plate after cooling down. If you need to use force to free the hinges, you still have some optimization work to do on your printing technique.

This is not a demanding print. If this is one of the first things you’re printing and it fails, expect other things to fail as well.

Hinge Design

Thingiverse has messed up this bit of text and I won’t bother trying to repair it because things on this website break at random moments. See the GitHub page for the hinge design explanation: