2D spirals

Hi - I have a CFD (Computational Fluid Dynamics) issue which I need to resolve and communicate with a 2D spiral … I’ve tried all the spiral plugins such as Curve Maker and Spirix but they don’t seem to be editable on Sketchup Pro 2023. Is there a simple way of making a 2D spiral which is editable? Thanks

You could try my 3D Shapes plugin from Sketchucation. It will draw 3D helices, but if you set start and end height to be the same, you can get a 2D helix.

Once drawn, R-click on the selected helix and choose Edit Helix.

I’m never sure whether a spiral and a helix are the same geometry - mine only grows proportionately with the number of turns. There are I think other forms of spiral that (for example) grow exponentially.

Are you wanting the spiral to be editable after you create it or are you just concerned about getting the parameters set correctly in the first place?

You may also need to define more precisely which kind of 2D spiral are you looking for e.g.:
arithmetic, parabolic, hyperbolic, logarithmic, golden…


Editable after creation - the spirals need to fit a certain profile determined by empirical data from CFD. Tricky to explain - but the best way to look at it is to imagine that the spirals which need creating are similar to the blade profiles on a large aircraft jet engine - they start from equispaced points on an inner circumference and finish at equispaced points an outer circumference. Their profile shape from inner to outer circumference is a slight clockwise spiral. As mentioned, the front view of the blades on a large passenger jet engine is very close to the shapes required. Whether this shape fits into a Bernoulli, Golden, Hyperbolic or any other shape is difficult to answer at this point

I don’t know any plugin that makes spirals that can be editable after being created, you can either play with the parameters until you get the one that fits in your shape or try to deform it with other tools like vertex tools, fredo scale, sketchy FFD( I’m not sure if this works with 2D shapes) or even the native scale tool.