Sheet Metal Extrusion for Flexible Printed Circuit Boards etc

S1mon

In Solidworks, whether by design or accident, it is possible to add extrusions to sheet metal parts (although it doesn't like to do this over bends). Over the years I've used this on a ton of projects to simulate flexible printed circuits. Sometimes it's a super low profile extrusion to show where contacts or silkscreen pin 1 indicators are, sometimes it simulates surface mount components. 

I'm sure there are other uses for such functionality, such as welded-on features for real sheet metal parts.

I can add other parts to a part studio with a sheet metal part, but they don't show up in the sheet metal view. I can't add extrusions to a sheet metal part.

I can add features after the "finish sheet metal" feature, but they don't unfold and show in the flat pattern.

This is another one of the many things that I'm used to doing in Solidworks which would prevent me from switching.

Here's an image of an example:

S1mon

On further review, what I'm advocating for is the ability to add/subtract material from a sheet metal part and still see it in the flat pattern. I see that with the "finish sheet metal part" feature I can modify the sheet metal solid in its folded form, but none of that will show up in the flat pattern.

Other related requests:
https://forum.onshape.com/discussion/13915/generalized-sheet-material-tools
https://forum.onshape.com/discussion/13185/sheet-metal-partial-cuts
https://forum.onshape.com/discussion/7312/countersunk-holes-in-the-sheet-metal-flat-pattern

lougallo

You can add and subtract material today as long as it is the same thickness.  We do have some featurescripts to do this today.  Is the intention of the extrude to add a new body to the flat?  You might consider just adding an extrude and then using this FeatureScript for this:  https://cad.onshape.com/documents/de14f4c15d3717ede541036f/w/f09be2ef961abc541533de1d/e/c6905caf290f114b8bc8e227

S1mon

I had not seen the Ribbon Cable FS before. I'm impressed that it handles components which are separate parts, not just extruded elements that are part of the same part.

That's cool to see, but it's doing the opposite of what I'm looking for. I want to design the bent up flex cable in 3D with components and very short extrudes for contacts and silkscreen and then be able to flatten it. The contacts and silkscreen are super helpful for making sure that pin 1 ends up in the right places, etc. I pretty much never want to design the flat pattern first and then bend up sheet metal or flex circuits. It's fantastic to be able to add details in the flattened state, but most of the design intent comes in the 3D for me.

I'm not super concerned with K-factors like in sheetmetal, since the bends are usually designed with clearance for tolerance reasons, but it would be smart to include some sort of K-factor allowances.

lougallo

@S1mon Understood.. however this is using a tool for Sheet metal for something you simply want to have flexible which is a bonus but not the real use case.  This sounds much more like a FeatureScript rather than a modification of Sheetmetal and maybe the best route would be to build this FS to work in the opposite workflow.

S1mon

@lougallo At one level, I agree that this is a less general use of sheet metal. However, there are benefits to the sheet metal functionality in Onshape - editing the flat pattern - which would go away if all I did was create an unbend feature which would work with FPCs. Also, Solidworks already works the way I want, minus the added flat pattern editing which Onshape has.

Part of what I'm showing in my very simple example image is a tapered section of the flex which crosses the bends. This is really hard to do if it's modeled only in 3D and unbent. There are other features like bend reliefs or curved sections which are easy to do in the flat pattern, but hard to do in 3D if they cross a bend. Conversely, modeling everything flat and then bending it at the end makes it hard to get all the geometry in the right place.

Ed_Lee47

S1mon, you might want to add your vote to my feature request https://forum.onshape.com/discussion/13915/generalized-sheet-material-tools to help with this.