# FreeCAD Tips and tricks I've picked up while using [FreeCAD](https://www.freecad.org/). See also [[CAD for 3DP]] and [[CAD for CAM]]. - using a spreadsheet and naming variables there makes it easy to reference the same value in multiple places from a single source of truth. - in a sketch, referencing geometry from the rest of the same body can help shortcut the sketching process, but if you end up reworking the prior features, you might have to rebuild the whole thing. If you're designing a brand-new part for the first time, it will probably save time to set up a simple registration sketch at the beginning of each feature sketch. - if a sketch does get in a bad way, the **Sketch > Validate Sketch...** tool has some good features. - Running up against a weird `result has multiple solids` error when I try to Pad something. - I checked **Tools > Dependency Graph...** but I don't have any cyclical dependencies. Not sure how to solve this one. - I ended up rebuilding the sketch on the underside of the existing object, and padding _through_ the existing object. - Aha! a clue: I made a test object. a 25mm x 25mm rectangle, padded 10mm. I added a sketch on top (same rectangle) and padded it successfully. But! When I introduced a hole into the original plate, the subsequent pad got the `result has multiple solids` error! So I think I need to focus each sketch on a single feature (pad or hole, not both). ## TODO? - [ ] https://hackaday.com/2024/07/01/freecad-foray-shells-for-all-our-pcbs/ - [ ] I would like to figure out how to do assemblies - [ ] Is TechDraw good for something besides printing clear drawings? - [ ] Maybe I should take a full class or something