Block Diagram
Summary Subsystem Testing Results
Sterilization
Cost
IP-52
Factor of Safety
Sterilization Testing
What we did
- Collect dust or germs with a Q-tip from an object into Petri dish
- Putting the dirty object in the UV light (1min) and using a Q-tip to take a sample into the Petri dish
Cost Summary: "Shall cost less than $300"
- Spent $331.70.
- Lots of ‘non-renewable’ costs.
- Estimate at least $90 less next time – This is within budget!
IP52 Standard Testing
SPEC: The product shall maintain IP52 protection.
WHAT WE DID
- Placed contents inside box.
- Simulated 3 mm of rainfall/minute for 40 seconds.
- Analyzed contents inside.
- Passed test.
Factor of Safety Testing
SPEC: The product’s structure shall support 30 kg load applied to the top and should be able to support 80 kg applied to the top.
WHAT WE DID
- Applied 160 lbs on lid.
- Added 20 lbs until 200 lbs.
- Analyzed box for bends/creaks.
- Passed test.
Electrical Challenges and Solutions
Challenges
- Logic designs were continuous
- ICs weren’t rated for supply voltage
- ICs didn’t work
- Needed circuit components
- ICs didn’t supply enough current
- Dangers with large power source
Broken Lamp
Solutions
- Use clocked logic gate
- Had to buy different ones
- Get creative!
- Run lots of simulations
- Used a solid-state relay
- Take caution
- Return/replace
Mechanical Challenges and Solutions
Challenge
- Failed 3D prints/getting supports out of seams.
- Waterproof seal made the lid uneven.
- Support tray corner became defective, wire grid disconnected from itself.
- Screwdriver is unable to fit under support bracket to get bottom screw in.
Solution
- Watched print so that it didn’t continue, redid print.
- Added hinge spacer to make lid flush.
- Solution would be to weld or glue corner back together.
- Screw from wood side upward and attach bolt.
Takeaways
- Double check IC ratings
- Buy more than 1 IC when ordering
- Build electronics in a lab
- Use separate testing environment/circuit
- Think about assembly long before actual assembly
- Update schedule more frequently
- Don’t go back unless you have to
Download the complete project document here
