As a kind of practical joke, I decided to try my hand at a partial spiral slider by using mm's "growing circle pieces" method. The punchline is that I wasted a good half-hour on it and that I got the end to snap into place
perfectly.
Hey, it's not quite so horrible! After a load of fiddling, I figured out that the method could be improved substantially (at least, for me) by halving the amount of anchors--this seems to make it a lot easier to get it round enough, with the only "negative" being that it's not perfectly circular. However,
asymmetry!=bad, as long as it's done tastefully. I think I'm gonna see how much further I can experiment with this logic, since it actually has the potential to work well.
For those who want to try this, the important part is that the anchors align every 180°. Each portion should also be perfectly symmetrical, so that the arcs look nice. The hard part is getting the tightest bend spaced correctly and making the first two arcs work around that--after that, it's a case of aligning the anchors, having straight lines going through the anchors and then adjusting the arcs' points to perfection. The last section simply needs a flatter bezier arc, which needs to be eyeballed.
Happy spiralling!
Just to prove that four-point arcs work with full Danish swirls as well:
