Materials
- Carbon fiber reinforcing fibers may significantly increase the electrical conductivity of the base resin. This can be an EMI/EMC benefit or a potential cause for other issues like shorting if you were relying on the plastic as an electric insulator.
Ultrasonic welding
- Typical 90 degree energy directs used in some ultrasonic weld joints require the use of Electrical Discharge Machining (EDM). Round energy directs may be appropriate and can be manufactured using traditional machining methods. A study outlined in this article of Assembly Magazine suggests that repeatable and strong welds can be obtained with round energy directors.
Threadlocker
- Loctite 222MS is not compatible with ABS and PC. The PC will degrade in a matter of minutes.
3D printing
- M3 is the smallest recommended tap size for Polyjet and other resins for holes with repeat assembly. Smaller may form but may not be robust. Care should still be taken for all sizes. Consider using Plastite screws.
Optics
- Cameras and illuminators should never share windows. You are likely to suffer light bleed.
- Always model camera field of views (FOVs) in CAD. This avoids unexpected camera occlusions.
Sealing
- Polishing a custom gasket mold with a small cross-section may cause flash at the parting line. You may be tempted to specify a polish on the gasket mold for sealing performance. If the gasket cross-section is smaller than your shop’s polishing tools, you may round the edges along the parting line, increasing flash.
- Most silicone lubricants are not compatible with silicone rubber. They will lead to rapid degradation. Instead use a Barium-based grease or other purpose engineered formulation. McMaster sells a Barium grease compatible with silicone.