Algodoo

I cannot figure out how it works. Would you mind explaining the "magic" behind what makes it work?

changing the friction of the gears the gears are set to change their friction from 1e30 to 0 when in contact with a laser. in poststep, they reset back to 1e30 if no laser is present. only one ratio of gears has no contact with a laser at a certain time. the shifter, the only real "moving" part, is attached to the input with a stretched hinge with autobend. the faster the input turns, the more it turns the shifter. The shifter has two circles on it that when in contact with the laser filter, they multiply or divide the collideset by 2. this, if you know binary math, adds a 0 in front of the 1, or if dividing, subracts a zero. for example: 001 times 2= 0001. if you take a look at the collideset chart, it's coded in binary. this will turn a collision layer "A" object into a "B" on one contact, and then a "C" with the next collision, assuming it is multiplying by 2. code is put in place to limit the max and minimum collideset of the laser filter.

ultimately, you want to have the laser hit three gears at any point to change their friction to 0, so only one gear has friction. the shifter changes which gear loses contact with the laser. make sense?

I will probably post a tutorial on how to make this

Very clever! Thanks for the detailed explanation! (All this time I thought you were only the best gun mechanic on Algobox. Now I know that you are much more than that! )

When you release throttle when it's on the last gear it breaks.
Good one anyways. it's not easier than mine, but I like it.
I seek simplicity on gearboxes