New Piston animation method

i realized in physics today that the motion of a piston matches the up and down motion of the point at which the connecting rod connects to the flywheel. So i came up with the following strategy to animate a piston and connecting rod on a wheel. Ill try it when i get home.
Note: this is for an ICE engine not a train wheel.

First create a wheel which will be our flywheel. Then place an empty that is locked to the wheel so if the wheel rotates it will follow. Then create your piston and lock its up and down plane of motion to a line so it stays in the cylinder. Then make it so that the up and down motion of the piston is synchronized to the up and down motion of the empty.

In fact, it doesn’t follow exactly, because the connecting rod forms a variable angle with the piston.
(Commented in

it was just a thought based on the idea of harmonic motion. The basis was on the fact that an object moving in a circle viewed from a 90 degree angle appears to be going up and down in a straight line (hence the transverse wave) and i figured since a crankshaft moves in a circle with a diameter equal to the stroke of the piston it might work.

thx for the attempt.

Yeah thats correct, the connecting rod forms angles with the crank Journal and the Wrist pin if you include them.

Thanks Pairal & bigalexe for tips & sharing, I have been looking for this simulation tutorial…now I did the simulation…I will just add fuel injection…maybe the opening & closing of the valves as well as the injection timings in the IPO…:slight_smile:

you can check my blend file here:

This file : Spike machine elysium.blend
froze my system Window’s and i had to reboot ?