At 09:46 PM 2/17/2005 -0500, you wrote: >Cool app. Works fine in 2K as well. According the program so far, our >pythons aren't stable at any speed :) Try a trail of -8 and an angle of 54, and then fiddle with the rest - they have various effects. For some trails, there are a few different, unconnected stable angles. This is what I noticed as islands of stability; a small change of angle or trail kills self-stability. Notice that shorter wheel base adds stability! >Mind you, I have to get the weight >distribution, and I have no idea how to figure out the mass height for the >front and rear, or how do decide where the "mass" is in relation to the >pivot and the rear axle. I try to visualize the mass of the legs and torso, but the connected nature of the masses above the pivot bothers me. It is a big damper and also hard to say what the moments should be. Re: the coasting stability, none of what I've read refers to the axle at all in the math; it is always moments about the contact patch. Also remember that the angle of gravity on the mass changes when down hill, weight force moves forward and the angle of the pivot relative to earth's gravity changes, "steepening" the pivot angle. So, on a 20deg slope the weight vectors are parallel to a 70deg pivot. The code I wrote always assumes level ground. I wonder how hard it would be to add slope in....I'll try to do more over the weekend. Ray ============================================================ This is the Python Mailinglist at freelists.org Listmaster: Juergen Mages jmages@xxxxxx ============================================================