The Top Down Design concept, often referred to as Skeletal modeling is one of my favorite topics with Autodesk inventor. This design process involves using a simplified part file or files, to drive a complex assembly. In many cases a single sketch can drive the entire design.

There is so much to say about the subject, and I’d just ramble on endlessly. In order to avoid that, I’ll chop up the article into separate posts, and update this introduction with any additions.

This collection will cover:

Keep checking back here as I’ll add parts to this collection.  This is not intended to be an all inclusive document on the subject, nor a tutorial how-to series, but instead some basics and various concepts as they come to mind, and as time permits.

What is it?

Traditional design management is a bottom-up approach, meaning that as you build things and add them together the design begins to take shape. An example might be a Turbofan design. If you build it like you assemble it, hubs, shafts, spools, compressor, etc. then the unit may not fit into the nacelle when you go to mount it into the plane. The oversight may cost you days of rebuilding just to accommodate the difference. Eventually you will run into a conflict.

Top-Down design techniques prepare the entire design on a framework that holds key portions of the design together. It’s a multi-purpose guide. The cool thing is that the design is adaptable and constrained to the framework such that when the frame changes, so do all the other components. Just how much or how little framing is one of the decisions that need to be made prior to beginning.

A certain amount of forethought and minor amount of vision are required with Top-Down framework, since it really needs to be thought out first.  That is the rub. You have to preplan something that you really don’t know the specifics of.  One of the biggest hurdles to get beyond is the need to constrain each component sub-assembly to one another.  You will need to start looking to the framework for origins and constraints.

Not to worry. I will show you some strategies that you can use to make things more fluid and easier to change directions with.

There’s no one-way to do it

One of the best things about Inventor and Top Down Modeling is that there is no hard and fast rule about how it must be established. You do what works for you. Once the basics are understood, there are of course some good foundation points that we should adhere to, and shoule learn from others such as industry leaders and experts like as Sean Dotson, Kevin Schneider, Rob Cohee, Rickard Lindgren, Dennis Jeffrey, and Mark Flayler, among others.

New concepts and combinations can be considered based on research from others that look for new ways to apply the applications to the design.  The interminably juvenile that just have to ‘learn the hard way’ often come up with new ideas from playing ‘what if’ for so long. That’s me.

I’ll discuss the industry solid foundation approaches with some design specific combinations that I have found useful, and let you gather the methodologies that will make your company more functional, organized, and more profitable, while reducing the chance of costly mistakes.