Four Bar Linkage Mechanism

Fri, 9 May 2014

Sometimes mechanisms don’t do what you expect them to do. Case in point, this little number which I was hoping to use as part of a low profile mechanism to drive the oars of a rowing boat. Despite the fact that it wasn’t what I was after, it was still rather interesting. Note how the movement of the hand back and forth is virtually flat despite being drive by a wheel, notice also how the right-left movement is much quicker than the left-right movement. I’m sure it will come in handy for something shortly!

The mechanism is actually a four bar linkage. The four bars aren’t immediately apparent so I’ve marked them up on this image. The baseboard itself makes the first bar linking the wheel to the orange bar. The other less obvious bar is the wheel. It is a fixed length piece that holds two joints at a fixed distance apart, it is still a bar in the mechanism sense even though it is round.

Expect to see this mechanism popping up in a character based automata soon!