I made two half matrix with bearing ball to let a place for the hole. Then, I put the copper wire in place, close the two matrix, and cast the silicone.
That's all.
I tried four models : one with copper wire, one with brass wire, one with steel wire, one with nothing. The last one is too flexible.
The video are coming next week because now it's raining. Yesterday I made a little test but TI was disable due to cloudy sky,
then my flight seem's like a flea drop !