Can you constrain the location of a part in an Assembly with dimensions?

erik_tribelhorn074

New user to OS.

Trying to help define location of a blister in a blister packaging application and since I had a model of the blister in SW, I figured this would be simple to model the blister card, pull both the card and the blister into an assembly, mate the front face of the card and the back face of the blister (planar mate, right?), then constrain it to its 'spot' using dimensions.

Now, a couple hours in with research, I'm wondering if I should have stuck with SW.  Can anyone help?

Below is the assembly,  the black marks are how I want to position it, including how it sets at an angle.

Jake_Rosenfeld

Hi Erik,

I think a better way to accomplish this in Onshape would be to model the blister card in the same part studio as the imported blister.

I emulated the workflow that you are trying to do by modeling a fake blister and deriving it into a part studio (basically a fake export from SW).  I then started a sketch, "Use"d the geometry from the outline of the blister, modeled a rectangle around it with the appropriate clearances, made a construction line down the midline of the blister, and angled the rectangle as appropriate. To angle the rectangle I had to press "Show constraints" in the Sketch dialog and delete the "Horizontal" constraint on one of the lines of the rectangle. A way to get around this would be transform the blister to align to the XY plane as you wanted it before starting the sketch.

Probably the easiest way to see what I did is to copy my document and double click to edit the sketch so you can see all the dimensions/constraints.

https://cad.onshape.com/documents/e9dad8e55769a9e0cb293566/w/62f378de2694fb5a9e770bd2/e/46db7844980b4a857ba58b52
https://cad.onshape.com/help/Content/sketch-tools-use.htm

Generally in Onshape we recommend modeling parts that do not move in relation to each other and rely on each other's Geometry in the same part studio.  These can then be brought into an assembly as the whole Part Studio and grouped together so they don't move in relation to each other.  Assemblies should be used for defining motion relationships between two or more parts.

edward_petrillo

Be sure the blister card is fixed in place (RMB to select, then "fix" in the context menu). Place a mate connector on the mating faces of the card and  blister, using X-and Y offsets to position each connector at the desired axis of rotation (arrowhead intersecting dotted line).  Create a revolute mate between these connectors, and rotate  the blister to the desired position while the mate dialog box is open.  Check the "limits"  box, set the minimum and maximum limits to the angular value displayed, and confirm the mate with the green arrow.  Fine-tune the position by editing the offsets on one of the mate connectors.

erik_tribelhorn074

Thanks for the responses!  I will work on both techniques to see what works best.

billy2

1. another approach is to use mate connectors. position the mate connectors, then position the parts. 
2. import a sketch from a part studio and use it to position blister card, the closest to what you're wanting
3. use in-context to edit everything in the assembly.

If the red part had datums, then you could have assembled everything to them. 

There's many ways to put these 2 parts together. Probably #2 is the closest to what you're wanting to do having that sketch appear in your assembly. Change the name of this partstudio to layout and use it to declare all the datums in your project. As a designer and opening your top level. I'd appreciate the small effort you put into organizing the top level and giving me some insight into your project structure. Don't just stick stuff in an assembly forcing me to figure it all out. Declare what you're doing, it'll help everyone out.