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.