Quick tutorial - How to make an helix or spiral curve

 From:  Michael Gibson
277.18 In reply to 277.16 
> I must make 80 Clickty-clac Zoom of the Mouse Wheel before to see a
> divergence between 2 arc segments !
> Is it compatible with your estimation of 0.1 degre deviation?

Well, when you're zooming in on the endpoint you're looking at positional deviation - that is going to be very tight, by the time you zoom in 80 steps you're seeing a very small deviation that is much, much smaller than the tolerance, so that part is very accurate.

I was talking about tangent deviation, though - this is the differences between the end tangent directions at each segment. This is a little easier to see - you can draw a tangent line off of each segment (hide the neighboring one to make sure your snap is on one particular segment), and then you can zoom in to see if there is a gap between these tangent lines. The gap is small (0.1 degrees in this case), but you should see it with only a little bit of zooming, especially if you draw the lines a bit longer.

- Michael