On the new Kossel printer I’m designing, I decided to go with some inventables components. I used them on my rockbot as was pleased with the result.
Because the pulley and the idler are different diameters the idler needs to be offset from the pulley so that one side of belt which will be connected to the slide will be perfectly vertical. I couldn’t find this magic number published anywhere so I download the models joined them on a common center line and then did a pocketing function to export the needed features to figure it out.
After that I created a sketch on the cut surface so I could draw a line from the pulley root to the od of the idler.
The offset number that I came up with was .150689″ (3.8275mm)