Surface Pattern - with options [NEED HELP]

romeograham

Hi folks,

I have a need to produce a pattern of counterbored holes, that share a normal direction, but the depth of which is driven by (with an offset) a surface or series of surfaces.


(here's a link to this doc, for what it's worth: https://cad.onshape.com/documents/b8b049f29e118ac362283888/w/76ff719b97d61faaaceee43e/e/bb23849d255c9d4e7d9f060a)

You can see that the holes are counterbored from below, but the C/B depth is driven by an offset to the curved surface on the top of the part.

To do this, I used a clumsy workaround of extruding surfaces to create edges so that I could produce Mate Connectors in an array offset from the curved surface....then used the excellent Transform PatternFS: https://cad.onshape.com/documents/25a0a6dfaa76e64574a5e0db/v/2774930de3ae2fb44180ceb8/e/4c62c06c4e0e4db3703a2d4c to create the holes. I can't find the author of the Transform Pattern, but I got it from the github repo by @dave_cowden : https://github.com/dcowden/featurescript


I would use this FS: https://cad.onshape.com/documents/c9eb49fac6fa713673b7e7c6/w/192ff3b7dceb0a84b3c139de/e/e4886efaea6f211a064a3042 by @maximilian_schommer if I could specify a "direction" for the patterned bodies (normal to the flat bottom of the part, rather than normal to the curved surface). I'd like to use this pattern, but use a point pattern (shown here on the bottom plane) to drive the positions of the pattern, rather than U & V quantities.

Another FS that seemed maybe useful (to produce a 3D array from a planar array of points) is Extrude Vertex: https://cad.onshape.com/documents/c5243aa82f2e404377db3017/w/2e1cd14f8ef6ad44b7c02b44/e/3e29af229aa22790e8d90389 (can't find author either right now), but it only accepts a single vertex per instance...which makes the 3D array a lot of work to create.

I have looked around quite a bit today, and haven't found a FS that will create a Point Pattern on a surface (or even better, offset from a surface). Then I could use that pattern to make Mate Connectors, then use the MCs for the Transform Pattern.

Ideally, these features would be combined so that I could:

• Define my pattern / array with a planar sketch (or selection of vertices or whatever)
• project those points to a curved surface (or offset of same)
• use those new 3D point array to drive a boolean operation, using a tool body that I can select

You can imagine the work this would save for operations for vacuum forming tooling (for instance), or any other machining operation where depth of holes needs to be driven by a complex surface.

Have I missed the perfect FS that already exists? Is there a combination of FS that someone can think of that I should use?
I don't mind doing a couple steps to end up with my 3D point array, but I don't want to make every single hole individually.

Thanks everyone.

konstantin_shiriazdanov

Sadly in OS there are no a reach instrumentary for construction geometry definition, but you can use some dirty hacks - use a vertex of extruded surface with offset option to define a mate connector for transform pattern.

https://cad.onshape.com/documents/712707bc35518915d0cb56c9/w/074f62161450ce4b9e644520/e/51f64f8a11cbd84792010dce

romeograham

@konstantin_shiriazdanov
That's a good way to do it - I hadn't thought of using the Transform Pattern that way to produce the 3D array of MCs.
Thanks for the suggestion!