Summary

Once we printed out the first original turtle we thought it would be very nice with a light inside the head.
We already bought a set of small USB-LED for less than 2€.
https://www.gearbest.com/led-light-bulbs/pp_625950.html

So we started to design a remix for the head to fit outside the USB-light. We used Fusion360. And made several tries.

The LED is directly soldered to a cable with an USB plug so it can be powered easily. The cable passes through the turttle body.

Picture are taken with the last version : tete_usb5.