Continue to Site

Welcome to MCAD Central

Join our MCAD Central community forums, the largest resource for MCAD (Mechanical Computer-Aided Design) professionals, including files, forums, jobs, articles, calendar, and more.

Top down design using skeleton model with family tables???


New member
Hi Folks,

I was looking for any information on the use of family tables to generate multiple assembly configurations that imploys the use of TDD skeleton models. I work for a company that designs medical research equipment and the only difference between some models are the x,y,z dimensions (overall size).

Is it posible to use family tables with skeletons at the top level assembly to generate multiple product configuations or should I be looking in another direction to achieve the desired outcome?

Any info would be greatly appreciated.
Creating a family table of the skeleton is a great way of controlling multiple different configurations of an assembly (and also documenting different steps in the manufacturing or assembly process). Using a family table of the skeleton (as opposed to a family table of the top level assembly) would be used when primarily you want to control different component locations, as opposed to controlling which components appear in your assembly configurations.

David Martin

Torgon Industries
jabbadeus makes an important distinction

A skeleton is a NOT a great way to control which components appear in your assembly configurations.

In, fact it can't because a skeleton is a part model. Which, for my modeling demands, makes it useless. Why can't they allow for skeletons to be an assembly? The whole concept of using a top down design paradigm seems pointless of you can't have you top mosts element control component placement AND components selection. What is the alternative, have a family table in the skeleton controlling placement and another family table in another assembly controlling component selection?

The best way is to forget about PTC's skeleton model (another unecessarily dogmatic restriction) and use the CONCEPT in a upper level assembly that functions like a skeleton (even though it isn't technically a skeleton model) that can control component placement and selection.

I use two different approaches to having assemblies control component size (maybe more than two). I use both technics sometimes in the same model.

One technic is to create an independant part model of the component (no external ref's) then have your assembly-level family table replace with the desired component.

The other is to create skeletons (not the same as PTC's skeleton model) in your assembly which are closed quilts that define the main features of your part model. Then you have your part reference these quilts your assembly (use datasharing:copygeom). You still have a family table in your part, but all it has to have is an extref (under add column you'll see ref model) to the assembly that it exists in. One limitation if this technic is that the part instances can only exist in the assembly instance that it references. But it has the advantages of the skelton concept and more.
Has anyone else got any thoughts on this idea of using surface geometry in an assembly to define a skeleton model? I'd be interested to see see whether this techniques proves beneficial.

I am working in an industry, where in most of our designs are family tables. We do not have Advanced Assembly module. However we use the sketch method to control the dimensions of the family.

Open an assembly and draw line diagrams in a plane that controls the solids / Assemblies that you may create. The parameters of this line diagrams are then used to create family of parts and families of assemblies.

There could be a better way of doing it, but then I find it very effective.