Openscad is great, but also look at DesignSpark Mechanical. Looks to be a good full featured NON-CLOUD based tool. I have started playing with it and it seems very nice. Free, but not open source. https://www.rs-online.com/designspar...nical-software. You mentioned new belts. Can you provide a link and also a before/after photo. Love to see what it does.