K'nex Car Seat Rocker
This is a car seat rocker that I made to rock a baby. It may have to be modified for the type or car seat but I'm sure you will like it. it is not suitable for heavy babies but one to six months should be fine.
This step is the base of the machine and the track that the car will roll on.
This is the gearbox that will move the chain back and forth.
Put the chain on the gears and make sure that the red rods are in the middle. There are 51 links in each chain.
Attach the car on the chain.The gearbox may have to be modified if your baby is too heavy.