New FS (3D cutouts for backplates 'n' stuff) initial method check please.

owen_sparks

Hi folks.

I intend to write a new FS and wish to ask if I'm thinking along the right lines before getting into it.

The intention is to pick a point on a sketch, then pick an electrical connector (or something similar) from the FS precondition (USB, HDMI etc) and then have FS construct the void required for the part.

So an automated approach to this discussion:-
https://forum.onshape.com/discussion/comment/19934/#Comment_19934

Forgive the crude models they're just to show the theory.  As shown these will only yield simple holes as if a sketch were extruded but real ones will be more complex with recess or counter-bores etc.

(1) Build a library of "boolean solids" of the void to be removed.  (The void required, not the actual connectors):-



(2) Make Back Plate with dimension of where to put features



(3) Add derived parts from the library and add mate connectors to the plate



(4) Transform Boolean Tools to mate connectors



(5) Boolean Subtract the tools.



So proposed structure for the FS:-

(a) Preconditions to accept sketch vertex, target body and a pick-list for feature type required.
(b) Code to derive existing "Boolean Tool Solid" from a public doc.
(c) Code to create Mate Connector on Sketch point selected
(d) Code to transform tool to new mate.
(e) Code to boolean subtract tool from target.
(f) Housekeeping code to tidy up.

Possibly need an option to rotate / reverse / realign the mate connector.

Does that sound sensible?
Have I missed anything, or got steps that could be combined into one?

Cheers,

Owen S.

kevin_o_toole_1

That looks like a great strategy to me, and FS is the ideal tool for this job. Putting your "negatives" in Part Studios is key here – it would be really painful to create those manually in FeatureScript, but importing them from a Part Studio is easy. Moreover, because of how FS imports work, you can continue editing those negatives in the Part Studio and see the results update.

I'd just add two things:

1. There's no need to actually create the Mate Connector in FeatureScript. All that's needed is a CoordSystem variable describing the orientation you want.
2. I'd add is a way to optionally control the orientation about that sketch point e.g. Select a vertical edge to make the cutout vertical rather than horizontal. This direction would become the x-axis of the coordinate system you make.

owen_sparks

Thanks @kevin_o_toole_1 I really appreciate your sanity check!

I'd initially thought of the mate route as I was imagining a PS with multiple tools scattered about in it.  This means to transform a tool into position we'd need to know where it started from.

If I understand you correctly your proposal has:-
(a) Each tool in it's own PS, with the point (on our tool) we want to match to on our target sketch positioned at the origin in the source PS.
(b) A coordinate system with the origin built on the target sketch point so the derive places the tool where we want it with no need for a transform.
(d) User selects an edge to control direction of custom coordinates.

Is that correct?

Thanks, Owen S

kevin_o_toole_1

Yep, sounds reasonable, but in (b), you will still have to do an opTransform. Code will be similar to that in the import docs, but creating the coordinate system differently, i.e. replacing toWorld(evMateConnector(...)) with cSys(sketchPointPosition, sketchNormal, xDirection).