[FeatureScript] Flex (Taper/Twist/Deform)

vesa_timonen

Hi,

I made a new FeatureScript to flex entities like in SolidWorks:
https://cad.onshape.com/documents/8263ed040c781494374b1c0d/v/6e6107b808cf2e20bd587ea7/e/a90fb0b85a5c



Regards,
Vesa

MichaelPascoe

Wow this is awesome. Thank you!

john_mcclary

Nice!

S1mon

Of course I try it on something a little more complex and Onshape is thinking...........................................................and fails.

There are a lot of small fillets on this and I guess I didn't really expect it to work, but Creo is able to do it. I'll have to try something a little more tame.

MichaelPascoe

Flex test 1 - Onshape document
I'm impressed. Pretty good considering this is a complex surface / part. Some tangency issues with the faces.


@S1mon I'm thinking for complex parts like these there will need to be options for sample techniques. This drop down could be placed in an array parameter so that multiple faces can have different techniques.

Example:
Surface conditions

• top - match tangent
• sides - match position
• bottom - match tangent

john_mcclary

So, it's turning into a mixed model then?
Is there a way to increase the mesh density?

MichaelPascoe

@john_mcclary
No, it is attempting to enclose or something, in this case the enclose failed and I created a composite part of the surfaces that it left.

Yes there is a way to increase that. I think the feature even remembers the previously used values, very legit. However, that won't solve the issue I was showing.

S1mon

I'm pretty sure what Solidworks and Creo (and Rhino, Alias, etc) do for this type of feature is taper/twist/deform the control points of the surfaces (likely with some raising of the degree of the NURBS). This would be far more efficient/robust than creating a ton of small fill surfaces. It's possible to extract the CVs from a curve in FeatureScript but I don't think that's available for surfaces yet.

As it stands, this implementation could be very useful to create an underlay to rebuild something manually, or perhaps for a quick 3D print or CAD space study, but it's not likely to be useful for production geometry directly.

I look forward to seeing further developments.

S1mon

Another possible way to do this: take a similar approach to what is done in 2D for RectToPolar (and the others in this document). It seems to take a ton of samples of points on the input curves and then deform them and do a FitSpline through them. It's not terribly efficient, but it does work (here I'm curving a logo along an arc):

vesa_timonen

@MichaelPascoe I tried to tackle tangency issues on V2 by adding one sampling point on the middle of faces. (This makes feature a bit slower but results are better.)
https://cad.onshape.com/documents/8263ed040c781494374b1c0d/v/514049e91b09e974678709e6/e/a90fb0b85a5c886f00eddca4
Before:


After:

MichaelPascoe

Very nice improvement!

I would say this is 20x better than previous face tangency. Some tangency issues still. I would say this is now a machinable part if it were to be machined on a corbel. Many thanks for this update!

Flex test 2 - Onshape document