Algodoo

You have to have air turned on(You have it turned off) and for now turn off gravity until the other bugs are worked out.

I will look at it some more to help and I will post more here later....

Try hinging (<-- wrote i right? ) those sticks on the circles borders. I'm not good at making air engines, but all of them I've seen on phunbox use this little trick to work properly...

You also forgot to set friction to zero on all the small circles. And you have more than one hinge per long thin box that attaches the box to the big circles, there should only be 1 hinge per box on the end that goes on the big circle. Also the long thin boxes should be out near the outer edge of the big circles and evenly spaced.

I would start over and try to build another one, my 1st try didnt work at all and I had to start over too. This time only use 3 long thin boxes per each big circle to keep it simpler and quicker to build.

with the gravity off and the air on your motor is trying to work as it is, it comes apart because the boxes arent evenly spaced on the big circles, causing it to vibrate apart.

I have changed the tutorial on step one to set the density on the long boxes that guide the circles to .15 kg.
I will post your motor that I fixed in the phun box soon.

I have edited the tutorial to change a couple of things and built a motor going by the tutorial and the motor works.

You can build another motor going by the edited tutorial that will work. I will post your motor that I fixed in the phun box shortly.

I posted your fixed engine and included one of my old ones. I have edited the tutorial and if you follow the tut it will build a good motor. The gravity is off, you can turn it back on if needed.