This model uses a torsion spring to pull the head and neck back into the body. It is extremely satisfying to play with, and the model (at 100% scale) works great! I haven't had time to play around with the scaling, but I wouldn't go too small due to the torsion spring; I would love to see what everyone can do with this and so posting a make would be amazing! Anyways, here are assembly instructions.
1: take the body (the part with the flippers) and take the head/neck/spring and place them inside like this. It may take a little bit of force to push the spring onto the hexagon, but I've tried it multiple times and it works great.
2: Take the shell and put it over the body as seen in the photo below. There are 3 hexagons extruding from the body, and 3 hexagons cut out of the shell. It takes a little bit of force to push it on so don't be alarmed, because it does fit.
Once you have done all of these steps in order your Yurtle is complete!
I used PLA for this project, and the only part I would recommend using a specific filament type is the spring, because the spring needs to be durable with slight give which makes PLA the perfect candidate. On my Ankermake M5 this print took about 5-6 hours and took 100 grams of filament at 100% scale. As always, I would love to see what y'all can make with this, so please post a make if you end up printing it, feel free to ask any questions, and see you next time I post something amazing ;)
The author marked this model as their own original creation.