I'd say there almost certainly has to be. On the 28mm stator I wound I got 28 turns on layer one to make a full arm. Those were cheek to jowl and touching each other. When I later removed that and measured length, it turned out that the 28 turns worked out to 0.61"/15.5mm per turn with 32 AWG/0.18mm wire.
So on an arm like that, with about 5.04mm of windable length (28 turns of 0.18mm wire side by side = 5.04mm) the 0.20mm wire would work out to about 25 turns per layer and 80 turns would have fit easily.
If we all keep some notes and post the info here on the turn counts and length per turn it will really make this all go a lot easier.
When you wind, in a perfect world, all turns in all layers will lay side by side and there will be no crossing turns. But I've tried to wind two layers on the 28mm stator arm that way and it is very difficult to keep the turns that way. Part of it is my old hands, brain, eyes, and keeping track of turns. Maybe you youngsters will find it easier.
It is best to finish the last turn near the bottom of the "V" to keep the transit runs closer to the center. So to put 80 turns on with the wire and stator I was experimenting with, I would plan to do the three layers like this I think:
28 ----> = 28
28 <---- = 56
14 ----> = 70
10 <---- = 80
If the turns on two adjacent arms used up all the room in the bottom of the "V" I would move the 3rd and 4th layers out a little ways, on one or both arms, to get some more room for the final turns.
I have not actually completed winding a full phase yet, and the counting is really an issue for me, it takes so much concentration. I think that if I try it again, I am going to use the 0.61"/15.5mm per turn to estimate the length of wire needed for one arm. That would be 0.61"/15.5mm x 80 turns = 48.8"/1240mm.
I would wind out that much wire and put a small temporary tape marker on the wire and spool it back up. Then I could wind with a cheerful abandon and not worry about counting turns. When the piece of tape showed up or got close I would measure and mark another phase and put the tape there.
Oops! I forgot something there!
The 48" length will only wind one arm and I need one continuous piece of wire to wind four arms with. So I would wind out 4 x 48.8"/1240mm or 195.2"/4960mm of wire and put three small tape markers on it to mark the end of each 48.8" length so I would know I have to move on to the next arm.
I really think, on these high turn counts, that I would prefer to start with a known length of wire marked as four equal length segments over trying to count turns as I worked.
I'll take a couple of more photos on stripping and terminating the ends of the windings. There is a lot to be learned the hard way on that too...