I have a straight spring-hard 0,9mm wire which I have to shorten

get someone else to do it for you

>>1077620
You won't be able to get a perfect circle.

>>1077620
circumference = 2*pi*d

connect the ends with magic if you want a perfect circle

cut a bit longer and hookup the ends with solder, a butt splice, or a clever knot if you don't need a perfect circle

Wrap a bunch of loops around a pipe with an outer diameter of 4cm, throw it in a forge to reset the memory, and cut the rings out.

File: Ecto.jpg (53KB, 600x399px) Image search: [Google]

53KB, 600x399px

anneal with a torch at required bends
bend with form/pliers/tube
heat again
temper

https://www.rcgroups.com/forums/showthread.php?t=1185463

>>1077621
/gsetdify/