Is it possible to extrude/loft-cut using a solid shape as a tool?

christian_petty

I'm trying to create a mockup of a thermo-molded tray that will cradle a complex 3D shape. I was hoping I could position the part in its final place, then extrude the tray from the mold direction using the solid part as a tool. I think extrude are only for sketches/faces, and boolean isn't sufficient since the complex shape would result in several undercuts.

Thanks!

S1mon

Short answer, no. 

Longer answer, you'll probably want to use the isocline tool to split the surfaces of the part using whatever draft angle is recommended for your thermoforming, and then use ruled surfaces at that same draft angle from those splits to create the surfaces which avoid the undercuts. There will be some surfacing work to either make an enclosed solid "tool" or a surface tool to split your tray base part. Boolean has a nice option to offset the tool body which can be helpful for tolerance reasons with something like a thermoformed tray.

stvnvl_8501

Can you share an example of this?  Have quite some experience with thermoforming molds and can't really imagine what you are trying to do..
Seems like you should be able to succed by extruding a projected contour and splitting the resulting solid with the (extendend) part surface contacting the mold. 

Evan_Reese

@S1mon
That's exactly how I'd approach it too.

christian_petty

Thank you for the help everyone.

@stvnvl_8501 check out https://cad.onshape.com/documents/a5ba328148e26cfef4da5b05/w/781072064898694c3cf82252/e/5677c1533803068e92257de7?renderMode=0&uiState=64eb8f981e720e60d98a3b1b

Essentially I'd like a tray to cradle this part as closely as possible in this orientation. Looks like I have to crate a surface to make it happen, but conceptually it seems it would make sense to be able to extrude the part as a tool from a block.

S1mon

There are CAD systems which have a “solid sweep” but at least in the Solidworks implementation the surfaces it produces are pretty bad if the sweep path is a curve. In this case it shouldn’t be too hard to construct what you need. 

Evan_Reese

There is a Project Body feature that essentially casts the shadow of a body, which can then be extruded, which might be part of a solution. I say "part" because it's going to struggle to terminate on the original body, and wouldn't account for the draft you need in a form so you might end up having to do it manually anyway. Here's an example though.

glen_dewsbury

Did I miss something in the question? Not sure what the transform is for.
A quick Boolean subtract seams to give a cradle shape.
https://cad.onshape.com/documents/ae39d9785e9d8914ab10960a/w/459cc02062d9e0ceed4ed0be/e/3446e2e18785c2780f69ac71  

Evan_Reese

@glen_dewsbury
I believe the goal is to find a way to press the object into a tray at any orientation without creating undercuts, like this example. I think a manual workflow like this is could be the way to go for a general case, but if you can get away with modeling some of it separately (or splitting and recombining it) you could project  each body and extrude up to it to get a start, like this example.

christian_petty

@Evan_Reese yes! Project body is a solid start. The examples are appreciated. I think that with boolean will work nicely.

stvnvl_8501

hi sorry for the late reply.
was out a few days.
@christian_petty Is this solved then?
@Evan_Reese s solution to me is quite elegant and closely resembles what I would propose.

glen_dewsbury

Thanks for the explanation. Makes sense now.
So essentially a tool path like I used in SW would be one answer. 

christian_petty

@stvnvl_8501 yes good to go. Might consider a feature request for this still. Thank you

stvnvl_8501

@christian_petty
I get it now, there used to be a similar command in creo as well, if I remember correctly. 
you could "sweep" or "extrude" a solid body  (or essentially its contour relative to the sweeping curve/ axis respectively) 
would be nice indeed. 

christian_petty

@stvnvl_8501 agreed. I'll put a request in