The document describes the process of 3D printing sensor node enclosures. It details the hardware components needed including a low power Arduino, radio transceiver, sensors, batteries, and battery holder. The author modifies an existing battery holder design to accommodate end-to-end batteries. Test prints are done to optimize 3D print settings for the new filament. OpenSCAD is used to design interlocking enclosure compartments which are iteratively printed and tested for fit until completed. The assembled sensor node enclosure houses all components.

1. 3D Printed Sensor Enclosure
August 23, 2017
John Oliva
joliva63@gmail.com

2. Background
• I am building a home automation system and
need sensor and actuator nodes
• Hardware and software is ready
• Need enclosure(s) for building nodes

3. Hardware
• Low power version of Arduino

4. Hardware (cont.)
• NRF24L01+ GFSK radio transceiver

5. Hardware (cont.)

6. Hardware (cont.)

7. Software
• Arduino library + MySensors

8. Sensor Node Components
• CPU/Radio board + Software ✔
• Sensor ✔
• Batteries + battery holder
• Enclosure

9. First Concept Sketch
• The design concept is a long narrow enclosure
with compartments.

10. Batteries + Battery Holder
• Low power CPU/Radio runs off 2 AA batteries
• Design concept is long and narrow so AA
batteries must sit end-to-end.
• Since I am looking to 3D print what I can, I will
print the battery holder rather than purchase one
• Let me check what is available on Thingiverse for
the battery holder.

11. Battery Holder
• https://www.thingiverse.com/thing:1755397

12. Battery Holder (cont.)
• Designed with OpenSCAD ✔
• I have used this one before ✔
• Design configuration only supports side-by-side for multi-
cell. Ruh Roh ✗
• Wait a minute – I know OpenSCAD so I can modify the
design ✔

13. Battery Holder (cont.)
• Original side-by-side version in OpenSCAD

14. Battery Holder (cont.)
• Modified to support end-to-end + no flanges

15. Battery Holder (cont.)
• New + old capability via customizer

16. 3D Printing Battery Holder
• Finally, its time to 3D print something
• Wait… I am using a new brand and color of
PETG filament
• Better make sure I have the settings dialed in
properly to get good, strong prints

17. 3D Printing Battery Holder (cont.)
• Use a really simple object that will print fast to
test the slicer settings
• Iterate and vary layer height, temperature,
speed, etc.

18. 3D Printing Battery Holder (cont.)
• Rate the results from various combinations to
find the sweet spot.

19. 3D Printing Battery Holder (cont.)
• Export STL for battery holder from OpenSCAD
and import into Simplify3D (my slicer)

20. 3D Printing Battery Holder (cont.)
• Generate GCODE using Simplify3D using sweet
spot setting and print!

21. 3D Printing Battery Holder (cont.)
• Some connectors that work with the design
purchased on eBay

22. Sensor Node Components
• CPU/Radio board + Software ✔
• Sensor ✔
• Batteries + battery holder ✔
• Enclosure

23. More Concept Sketches

24. 3D Printing Enclosure (cont.)
• Measure internal parts in order to design the
enclosure

25. 3D Printing Enclosure (cont.)
• Use OpenSCAD and customizer to design enclosures and insertable
bottoms – this may take some time to get it right

26. 3D Printing Enclosure (cont.)

27. 3D Printing Enclosure (cont.)
• Design and print clip for connecting compartments

28. 3D Printing Enclosure (cont.)

29. 3D Printing Enclosure (cont.)
• Uh, oh. Too tight.

30. 3D Printing Enclosure (cont.)
• Better

31. Sensor Node Components
• CPU/Radio board + Software ✔
• Sensor ✔
• Batteries + battery holder ✔
• Enclosure ✔

32. Assembly
• All parts printed and ready for assembly

33. Assembly (cont.)
• Battery, battery holder in compartment

34. Assembly (cont.)
• All components in compartments

35. Assembly (cont.)
• Fully assembled

36. Future Improvements
• Tune dimensions of battery holder and
compartments for a better fit
• Add fillets to enclosure to strengthen places
where walls meet
• Experiment with other enclosure
configurations – not long and narrow