Edit, 24. 7. 2026: Updated the MOST 1:100 version and edited cover image. Added MOST 1:100 description.

MOST 1:100 explained

MOST stands for Magnetic Open Source Toys. 1:100 is the scale. These are the rules:

1. 1 real meter = 1 toy cm

2. Use ∅ 5mm × 2mm neodymium magnets

3. North is always facing upwards

It's easy: 1 meter in the real world is 1 centimeter in the toy word. A 5 meter car becomes a 5 centimeter toy. A 2 meter tall hero becomes a 2 centimeter action figure. To ensure compatibility between all toys the north pole of the magnets always faces upwards.

It's like Gridfinity but for toys! You can read the long version here.

WARNING:

SWALLOWING MAGNETS MIGHT BE FATAL!!!

Magnets and 3D printed parts are in no way suitable for small children. They might break and leave sharp edges, so make sure the kids are old enough to know what they're doing! 

Also make sure you don't have a steel nozzle inserted as it might pick up the magnets while printing and ruin something.

Print instructions

1) Open the .3mf as project in PrusaSlicer, adjust settings according to your taste. Every pause is pre-dialled. Skip step 2) and insert the magnets as explained in step 3).

2) If you're more of a masochist tinkerer use the .stls, navigate to the according layers, insert a pause in the slicer (right klick on the slider at the according layer in PrusaSlicer).

3) Insert the magnets according to the screenshots below. North always faces up according to the orientation of the model – hence the different orientations for the inserts. Determine north as explained in this article. 

4) Get Thag the dino jockey / snack and start riding!

Thanks to all my club members for making this possible. If you like the model, consider becoming one yourself. 

If you want to support me without costs, tell your friends and share my models on your social media! <3

If you have questions and inputs get in touch! Happy printing!

Edit 16. 12. 2025: A user pointed out, that the model is not at the correct scale to fit the LEGO saddle I constructed for it. So I noticed this model is so old that it doesn't fit the 1:100 scale I use for all my models for a long time now. Because of this I switch the model file to the improved one you'll find in the paid version.

Yes, I know it's blasphemy as we already have the awesome mother of all flexi dinosaurs, the original Flexi Rex from DrLex. But in order to achieve my goal of creating an entire Jurassic Park, I need a version in my style to match that of  Günther, Theobald and Bertha. 

To find a name for her, I held a prize draw and my club member SpeakingOfBrad won and chose wisely. Thank you for your support and good choice! If you, the reader of these lines, would like to have a chance to choose a name for my future creations, join my club!

Tessa the T-Rex has a hinged jaw so she can chew the heads off anything that gets in her way. Chomp, chomp! Gulp! Yummy!

In the style of Theobald, I decided not to make the model parallel to the baseplate. This makes it more dynamic and fits in with my other FlexiDinos. With its sturdy hinges, it is as robust as you would expect from the fiercest predator of all time. 

If you know my models, it's always my aim to make them as quick and easy to print as possible. This one is no exception. I am currently printing it with a .6 nozzle and, when I am particularly impatient, a .4mm layer height. I have also managed to get good results when scaled down to 55% of the original size. I think you could go even smaller with a smaller nozzle, it's up to you to find out.