Hi Hello, as part of a project I have undertaken, I am working on the design of a roller chain in SolidWorks. I am following the steps from the YouTube video titled “Chain and Sprocket Design Assembly and Motion Study: SolidWorks Tutorial.” The distance between the sprocket centers is 296.2 mm and I am going to place sprockets with 18 and 36 teeth.

Let me explain everything step by step. The outer link has a pin diameter of 4.44 mm, however, the circle I’m using for the coincident mate is 4.45 mm in diameter because the bush of the inner link also has a 4.45 mm diameter. At the chain pattern stage, I have selected the same Flip Alignment for the path and for the inner link, and the opposite Flip Alignment for the outer link, following exactly what is shown in the video.

Next, I added coincident mates between the front plane of the overall assembly and the midplanes of all the links (the midplane is the plane located in the middle of each link). Now we come to the serious problem. After that, I start adding coincident mates between the circles of the inner and outer links. These are supposed to show up in orange, which indicates a fully defined mate. However, after a certain point, the mates start turning purple. For example, I create 10 coincident mates and all appear orange, but when I create the 11th, suddenly 7 of them turn purple even though they were orange before.

The reason I used 4.44 mm and 4.45 mm for the diameters was to allow for a small clearance. Please tell me what might be wrong and what I can correct in order to finally make the chain work properly.