I couldn't solve using logic only. Had to rely on what I thought it should look like to fill in the squares. Nice end result though!

Okay, this one is almost impossible, so here's a tip: The spiral moves counter-clockwise towards the center. Took me forever!

Thank you, Ekkonic. Counter-clockwise is an excellent tip!

A great thank to Ekkonic for the "counter-clockwise" advice.

First try!

It was intimidating at first, but more or less easy. I did all of the logical parts first, and then the center told you exactly where the middle tail starts.

Really nice. Thanks Leradraco. You can get to the center by logic alone and then the pattern reveals itself.

Thank you!

Thanks.

The 12 starts in R6, connect all the big numbers with diagonals. remaining 1s form additional rings of the spiral outward.