Kind of new to solidworks and I've been designing an assembly that consists of about a couple of dozen parts arranged into half a dozen subassemblies. My experience has raised a couple problems that I can't figure out.
1) A couple of the parts have features that drive many of the remaining parts' shapes and it seems reasonable to use an equation or a design table to put these dimensions in one place for all the parts to reference as needed.
Is there a way in an assembly to reference an item in the equations of one of the *other* parts??
Say Part1 has an equation "od"=42.0, I have tried creating an equation in the assembly and I've tried things like: "D1@Sketch1"="od@Part1" and various other syntaxes but I just can't make it work. It seems that equations are only local, that is, you cannot reference equations that are not in the equations of the current part.
SolidWorks "Help" talks about global variables, but I'm a computer scientist and these don't look "global" at all, just static variables, i.e. something you set and which isn't driven by a reference to a dimension or other object. Needless to say that difference in connotation has made me spend quite a few hours trying to "force" them to act globally.
2) Why can't I have relative paths in external references? What a pain, I can't move files to a different parent directory even if I keep the SolidWorks "subtree" the same? Makes reorganization of filesystems a tragedy. Just plain dumb.
I believe that when two parts are in an assembly you can reference the dimensions of one in the other in the usual way. Perhaps I am just thinking of this from part to assembly.
There are examples of driving dimensions from excel or access in the API help and I think on the SW subscription site.
Yes but you can only reference dimensions. You cannot reference equations or design table elements. At least not that I can figure out.)
What I want is to create an equation table in a part that has an outside diameter that I can vary. This OD winds up driving the sizes of about six other parts in the assembly. I've got some circles that I want to be smaller than this OD, like "ID"="OD"-.01.
Great, let's do that with dimension references... First you need to create an assembly that includes the OD part. (Which you might not actually want to do because this might be part of a subassembly that gets assembled prior to mating with the OD part but as you can see it's dimensions are still dependent on the OD part.) Anyways, Create a circle in the other part. now constrain it concentric. Now constrain it .01 smaller than OD... Oh wait... you can't; no such constraint is possible. OK let's create another concentric AND equal construction circle but lets create a dimension between this circle and our desired circle and set that to .01. Fantastic... Problem is there are two solutions. One circle that is smaller by .01 the way we want... and one that's bigger. So you resize your part and then everything goes to hell because the part can't rebuild because SW prefers the closer or less convenient solution or your wonderful interference fit just became a loose, sloppy fit.
The best solution would be to be able to say "D1@Sketch1" = "OD@Sketch4@Part1" +0.001 which you can do however there are a few variables that drive so many parts and assemblies that it doesn't make sense to force them to be included as components. And it would be better to say "D1@Sketch1" = "OD@Global".
For instance, I'm press-fitting a bunch of delrin parts into stainless parts, Let's say I know that my press-fit is .0015 per inch of diameter over but I might want to change this value if I change to aluminum or polycarbonate for instance. Right now I have to create a phantom "part" with a .0015 dimensioned circle in it AND the crappy thing is I have to include this "part" into an assembly with the desired part so that the desired part can reference the phantom part. Just plain stupid. There should be a "Project" and you should be allowed to have variables, or equations, set in the Project that any part or assembly can reference without phantom parts or such silliness. There is a need for abstract values or "dimensions" that are not associated with a part, an assembly or the inclusion of such yet still affect all the components of your model. (Coatings are another I can think of, are you going to chrome all those pieces? that changes the fit of everything.)
I'd even be ok with a lack of project concept and just have one giant super equation table that EVERY part in SW has the same access to the same variables. Even if one part is from a missle while another designed for a milking machine. But then again I don't have a lot of projects.
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