[ChrisH]

Our level of detail depends largely on the criticallity of the system.

We did do calculations to determine the gear ratios for the drive, but didn't do extremely detailed drawings of the skyway wheels or the drive sprockets. These items were roughed in on the overall assembly, but we didn't figure out exactly where everything was going before starting to build. There were "keep out" zones on our overall assebly drawing to cover this. Besides you don't want anything important in the drive bay near the chain anyway. To much risk it will get damaged by the chain if something bad happens.

On the other hand, our ramp gripping arms were completely modeled, including the motion, before we built anything. In fact we used the CAD drawings as patterns for the linkage parts when we built them. Our box gripper and lifting arm were also modeled and checked using FEA before being built.

Our drive motor mounts and the gearbox for our arm were mostly done in CAD before we built them. I say mostly because Rick Varnum, our machinist, (who is probably lurking out there somewhere) decided we needed to lighten up the sides of the gear box so he used a CAM program to generate an NC program for that. It took less time than adding the pockets in Inventor. Besides the pockets were not critical to the function of the gearbox or any mating features.

On the other hand, our "light lifter" which kept our light from being bashed on the bar, was built on-the-fly and never has been documented.

Over all, I think we did more layout and planning this year than ever before. We also placed higher than ever before.

A coincidence?