Combined camwheel and gear for sewing machine

thingiverse

This camwheel has two functions: one is as a gear moved by two rotating pins and one is as camwheel to steer the zig-zag function of the sewing machine. It is a Vroom and Dreesmann type, that has been sold into the thousands in the Netherlands. Because a plastic wheel is mounted on a large metal piece, it breaks after some time because of ageing of the plastic and different expansion coefficient of the metal and the plastic. Likely similar machiness have been sold elsewhere. We (at saved tools Groningen) see this type of defect often, like in my previous camwheel design. Until recently we had to scrap these machines as replacing the broken camwheel was impossible: the shaft on which it is mounted cannot be taken out. So the wheel is printed in two different parts that are connected by a 3d printed connection with pins that fit into holes. Some hard PVC glue will hold it better together if required. If you are printing this wheel you have to flip the box that is present to cut the part in two pieces.