Your design must follow the CAD convention to be accepted by the team. If it does not adhere the rules listed below, you will be notified to modify your model. After the design has been accepted by the team you are can begin the manufacturing/making process. Please reach out to the mech leads for any questions or ambiguity in the guidelines.

Sketch Rules:

  1. All parts of the sketch must be fully defined.
  2. DO NOT use any assembly features.
  3. Eliminate redundant dimensions by defining relationships with mates and constraints.
  4. Any fastening holes must be done using the hole wizard. Bearing can also use hole wizards for countersunk flange.
  5. Use Socket Head Cap Screws for the 3d prints. For metals only use flat head screws.
  6. ANSI metric standard should be used for all fasteners and hole wizards.
  7. Screws used must be of size M4 (0.7mm pitch) or M5 (0.8mm pitch) or M6(1mm pitch) unless they’re for off-the-shelf components that require specific screws, for example M3 for linear slides. However, you should note that in your technical drawing.
  8. Include all fasteners (bolts, washers, nuts) in assembly CAD whenever possible. Fasteners should be grouped in a subassembly to join components within that subassembly. Fasteners that connect a subassembly to the main assembly should be added at the main assembly level.
  9. Justify using fully or partially threaded screws.
  10. Add all the off-the-shelf components to the “off-the-shelf” notion page, while also adding the components to the assembly file of the assembly that is being used.
  11. Parts must be made using Biotron’s part template.
  12. Parts must use Biotron’s standard naming convention.
  13. Assemblies must include all components fully defined using appropriate relations, with all necessary dimensions properly specified.
  14. While revising, identify any machining, sanding, drilling, and filling that has done in the previous version and make the new part filt and ensure the new part is modified so that we don’t need to make the changes again
  15. All the fillet and chamfers must be made using a feature. Do NOT include them in the sketch.
  16. Similar fillet or chamfers must be made in the same feature, so that you can edit them all together.
  17. While working on the assemblies, make sure the chosen tolerance is manufacturable, with enough clearance to be assembled and no parts going through the walls!
  18. Before designing the part, choose the appropriate material and manufacturing methods.