Feb 8
Again, thanks. I, too, like to get "into it" sometimes. I guess that some of us engineers and inventors are "just born that way"
I will try out Creo Parametric for 30 days, but first, I'll find a third party book on the topic, and study up. I might also (blasphemy!) consider an alternative to PTC. One product retails for $199.00, and after all, "business is business."
Slightly off topic, let me here sing the praises of X-numbers, a free, downloadable add-on for Excel which allows arbitrary precision arithmetic to be used, seamlessly, within an Excel spreadsheet.
I do linkage analysis with Excel, setting up a spreadsheet with, say, 720 rows, each for a half degree of an input crank rotation, and then working through the trigonometric formulas, column by column. It beats writing code, and Excel lets me graph results in an almost hassle free way. Sometimes, though, Excel's native 15 decimal places of precision aren't enough, especially when finding deriviatives of complicated position versus crank angle results by the "lazy man's" method of just setting up finite difference expressions. I set up X-numbers to give me 60 decimal places of precision, and then, as a trial, compared accelerations around a circle done with finite differences against the simple omega squared times R formula. Thel largest devation was by a ratio of 0.999975. This seems good enough!
X-numbers comes in 2 versions, one for 2007 and later Excel versions, the other for pre-2007. Both are reasonably fast, on a by-now-ubiquituous Pentium 4 or later, 2.7 Ghz or up. Enjoy!