ALittleSlow

If your PC VM doesn't work out, maybe try a PowerPC emulator?

Have you looked at the NeXT Command Center?

jodawill, I found MacNQC downloads on the Wayback machine: https://web.archive....m/rbate/MacNQC/ I just wrote a quick article on MacNQC on Brickwiki, hopefully to save the next person some of the frustration you're having. Let me know how things go and I'll update the article. Or better yet, you can update it.

You're right, I'm fudging by using the year of the public debut of the first collaboration, not the year it was conceived.

I haven't seen any movement on the index, so I started one at http://www.brickwiki.info/wiki/Category:GBC_catalog, using some of the references that are in this topic already. I called it a catalog rather than an index because I don't think BrickWiki is a place to list every GBC MOC in the world, but it's a good place to document each type of GBC. The http://www.brickwiki.info/wiki/Clock_lift entry is maybe the best format. A wiki is probably a better place for this kind of thing, but it's no place for a GBC discussion. That should remain here, of course. It's a wiki. If you don't like it what I've done, fix it. On another note, did you know 2015 is the 10th anniversary of the GBC? It went on public display at Brickfest '05 (DC): http://news.lugnet.com/robotics/?n=23244. We're planning to make a big deal out of it at Brickworld Chicago 2015. We're still in the early stages. Got some ideas? One of my goals is to earn the GBC world record back from the Europeans.

I think keeping an index is a great idea, but it's hard for a single person to keep up with it. What about putting the index on a wiki so the whole community can do updates?

The coefficients of friction Philo provides for tyres won't help you. What you need for the calculation you're interested in is the rolling friction, or rolling resistance. The relevant equation is Torque to overcome rolling resistance (T) = Vehicle speed / rotational speed (ω) * rolling resistance. Estimation of the rolling resistance, as you might guess from the other posts, can be a complicated affair but I expect at LEGO scales it mostly depends on the tire and the vehicle weight. -Brian A. Thanks @jodawill for pointing out that the rolling resistance in the above equation is resistive force, not the coefficient of rolling resistance. For a rigid tire on a rigid surface, this equation reduces to T = r * F, where r is the tire radius and F is the force at the axle pushing the vehicle forward. The coefficient of rolling resistance, Crr, is defined from F = Crr * N, where N is the normal force the axle exerts on the tire (i.e. the weight on the wheel). If you make these two substitutions (the first one being dubious), the original equation becomes T = Crr * r * N. That gives us an easy way to determine the Crr, with a caveat I'll give later. I'll call it a "coast-up test" because it's a coast-down test in the opposite direction. Build a simple test vehicle with all the same tires and no drive train. Put it on an inclined plane (i.e. a board). Measure the height of the vehicle off the ground level. Let the vehicle go and time how long it takes to reach the bottom. Using the standard acceleration equation s = 1/2 * a * t^2, where s is the length of the plane, a is all the accelerations experienced by the vehicle (assumed to be constant) and t is the time to cover distance s, it can be shown that the definition of Crr, Newton Laws and this last equation can be combined to h / s - (2 * s) / (g * t^2) = Crr, where h is the height and g is the acceleration of gravity. Now you have a coefficient of resistance, which is dominated by the rolling resistance. You can then apply this using T = Crr * r * N to any vehicle. Now for the caveat. Crr is going to increase with torque, especially for softer tires, and in this coast-up test the torque is minimal. There are more caveats. It only applies to the surface you tested on. Carpet, wood, and gravel will give you different Crr values. Crr may also increase with speed. Finally, the equation neglects the momentum gained by the tires which will decrease the value of t (increasing the apparent Crr), so it would be good if the body of the test vehicle is much heavier than the tires. Probably at least by a factor of 10.

Thanks, that was nice of you!

I'm the Brian who made Lucas Oil Stadium, though both Bryan and I are in IndyLUG. Next meeting is the 2nd Sunday of April in Clayton, IN at Mark Peterson's house. Would love to see you there, and bring some MOCs! Send me a private message for the address. -Brian