Quote:
Originally Posted by sanddrag
Ether, what would it take to get you to come over here and join my team?  You mathematical contributions to the Chief Delphi forums this season have been fantastic.
Regarding your model, and the (neglected) friction, I've learned it does play a BIG factor. |
Thanks for the kind words, but I'm an East Coast / Midwest kinda guy. Although I did take a business trip to San Diego 25 or so years ago and the weather was
amazing. And the San Diego Zoo & Wild Animal Park is among the best in the country.
I've updated the spreadsheet to allow the user to enter a friction estimate. I've also derated the motor performance somewhat; the rationale for that is included in the ZIP file. Since friction does play a large role, the value you enter will have a substantial affect on the model prediction, so it's important to try to get a reasonable estimate. I'm pondering ways to do this.
One thought is to push (with a small postal scale) or pull (with a small fish scale) the unpowered MINIBOT at a constant speed up the pole with and measure the force, then subtract the weight. This may be difficult to do accurately.
Or, make a pole with a reasonably friction-free pulley at the top. Run a lightweight but strong line (perhaps fishing line) from the MINIBOT over the pulley, and on the other end hang weights until the MINIBOT will just barely continue to climb when given a slight push. The difference in weights should be an approximation of the rolling friction. Make sure the MINIBOT motors are open-circuit (not shorted) during this test.