Inventor Pro Help if Possible

[docdavies]

Folks,

Thank you all, after a punishing, but rewarding weekend (and all of your great advice), I have a much better handle on constraints and such. And Marie, after reading my book, I now know more about your advice and it is very helpful.

Couple more things:
1. How do you switch views quickly to be able to pick the appropriate surfaces for constraints. Some times when I use planes I get very "unusual" results.
2. The 8020 CAD model I use does not have nice clean edges to use for constraints. Is there a best practices for using 8020 tubing.
3. No matter how much I try to hold dimensions to fixed numbers, I run into the problem that things don't align completely. Is there a way to edit a piece of 8020 in an assembly so as to either "stretch" it or "shrink" it?
4. I've found that putting 8020 together using constraints based on holes and the center of the 8020 tube works well. I'd like to go back and edit past drawings using this technique. Is there a way to pull a deep seated piece of tubing (which has constraints associated with it) out of the morass to add a few holes when I can't get a view of the piece?

Thanks for your patience everyone..... GP lives on!!
Doc