Can I faithfully rebuild a simplified curve?

Simp Con
This is a mechanical drawing that consists of straight lines and arcs. I ran SimplifyCrv to make sure it was one.

It will be extruded next to form a 3D component, but first I would like to unify or rebuild it so I am not simply extruding a formation of 15 or so straight lines and arcs.

The problem is, rebuild tends to turn a simplified drawing like this one into a banana. Even with a very large allowance for points, it cannot seem to faithfully reproduce a structure formed from straight lines and arcs.

Is there another way to glue together a unified version of this line drawing that will faithfully reproduce the original structure? Maybe a plug-in?

I have 8.0 but have not yet made the transition from 7.0.

Thank you for your time and insights. Michael
simplified connector.3dm (130.3 KB)

It’s literally mathematically impossible to 1:1 match some curve with a curve of a different degree, it’s always going to be ‘fit.’

There is no problem with extruding 15 or so straight lines and arcs, as long as that’s the “design intent” and the precision of the arcs is good enough that downstream operations will work.

Converting this to a “simple” Degree 3+ smooth curve would require hand-fairing.

If you run ExtrudeCrv and set SplitAtTangents=No, you will get an object with four surfaces (six if Solid=Yes) - including two with internal G1 joints. I don’t recommend this, but YMMV.

The idea is to try to determine if this stainless steel connector, if pulled straight or nearly straight, would remain elastic or lose its flexibility and go stiff, like a screen door spring pulled too hard.

I read that Rhino has a command, MassProperties, that can probably do a lot of the physics required to answer this question. But I would like to test MassProperties and experiment with it using a unified solid.

Suppose I tried FitCrv and 1000 points. Would that unify, if not perfectly replicate, the lines and arcs? Michael

Rhino can do none of those physics without some kind of FEA plugin, which will convert the geometry in to some sort of a mesh and not care about the separate surfaces.

Access to Mass Properties is under the command Volume.


Those are just some basic calculations on a static solid, nothing to do with what happens when it deforms under load.

Understood. There is more to the problem than the shapes of the connector, e.g, the stress/strain behavior of this particular steel. But there are some very helpful calculations on offer. Will try my luck both ways: Helvetasaur’s and all 15 curves.