Sketch Wrapper FS question, how do you properly use the "Plane or mate connector" option?

David_Bone

I have tried several orientations of the mate connector to get the wrapped geometry to orient correctly onto the surface, but the best I can do seems to be getting the geometry to be right side up, but 90° offset around the cylinder.  Are there any other options or documentation for using Sketch Wrapper?

konstantin_shiriazdanov

my intent with this FS was to allow to wrap sketch on any plane to any cylinder, so you don't need to to build sketches on tangent planes. the disadvantage is that wrapped curves generally are not aligned with source sketches, but you can achive that by manipulating mate connector position relatively to the sketch. in your case you apply rotational transform at 90 deg, which is equivalent to the mooving mate connector at 1/4 of circle perimeter along it X axis.
https://cad.onshape.com/documents/39da3c57c13b8da2bca303bf/w/f8bc5eaa7d67829ebd4e5afa/e/71e77622068b86cdd9676fff

konstantin_shiriazdanov

if you share the document I'll take a look. the thing may be in the orientation of the surface coordinate system

David_Bone

Here is a link to an example...
https://cad.onshape.com/documents/f83c06ffc9d644b15eedad90/w/80c6f9c07d9d6b75bdf6b10c/e/46c969839b235074de306a80#comment5a8f28e563a4450f83498a74
Version V4 shows the result of the wrap
Main shows the final result with cutouts in the base cylinder
I have added a few feature comments

konstantin_shiriazdanov

my intent with this FS was to allow to wrap sketch on any plane to any cylinder, so you don't need to to build sketches on tangent planes. the disadvantage is that wrapped curves generally are not aligned with source sketches, but you can achive that by manipulating mate connector position relatively to the sketch. in your case you apply rotational transform at 90 deg, which is equivalent to the mooving mate connector at 1/4 of circle perimeter along it X axis.
https://cad.onshape.com/documents/39da3c57c13b8da2bca303bf/w/f8bc5eaa7d67829ebd4e5afa/e/71e77622068b86cdd9676fff

David_Bone

So it appears the following equation will result in a properly aligned wrap.
(PI*(#CylinderRadius/in)^2)/2 in
I will test a few more examples to see if this is consistent.
Thanks for the info, it gave me the insight to eliminate the additional alignment steps!
And let me know if you ever include an add/remove update.

konstantin_shiriazdanov

David_Bone said:

So it appears the following equation will result in a properly aligned wrap.
(PI*(#CylinderRadius/in)^2)/2 in

i would say if the desired angle of rotation is "alpha" in degrees and cyl radius is r then the mate connector should be mooved alond X axis at distance +/- alpha/180*pi*r. if alpha = 90 then distance would be 1/4 of circle perimeter.

Add/remoove functionality is not so easy, because those wrapped curves are not topologically related to the faces, they are simple splines through mathematically calculated points. but i could make an fs that would allow splitting faces by wrapped curves, and then one can use "thicken" command

Ronan_McAllister

Hi, 
I've started using this FS & it seems to work really well, but I'm a bit confused with how exactly I'm meant to get the orientation right. (Lots of trial and error so far.)
When I open the Sketch Wrapper tool, by default it places the lines upside down on the cylinder relative to the orientation of my sketch. I know from your comments above that I can adjust the mate connector position/rotation, but why does it go upside down in the first place?
I can see the axes it is using to wrap the sketch (the burnt-orange coloured ones), but I can't see any way to adjust their orientation. Is this expected behaviour?
And in general, to repeat David's question above, is there any documentation for using Sketch Wrapper? It would be really helpful just to have a simple set of instructions explaining things a little more.

konstantin_shiriazdanov

@Ronan_McAllister

> but why does it go upside down in the first place?

It is because this is how cylinder coordinate system is calculated by default with built in featurescript functions.

I could recalculate it for cylinder, but i don't know how to deal with cones, so it stays like that. Todays sheet metal instruments in Onshape are good enough to wrap contours on cylinders, at least you wouldn't face a problem with sketch orientation.

konstantin_shiriazdanov

So for anyone intrested in v24 of Sketch Wrapper I just added option, which tryes to reorient sketch and cylinder coordinate systems to adjust sketch orientation. It only takes effect for cylinders and when sketch plane is parallel to the cylinder axis.

Ronan_McAllister

Amazing, thank you! I'll give it a try.