This is part of a series on the Hawkeye Pi Camera – a Kodak Brownie Hawkeye inspired Raspberry Pi camera with a budget thermal printer.
The camera body is loosely inspired by the Kodak Brownie Hawkeye of the 1950’s.
The 3D model was created in Fusion 360.
The first step was creating a sketch of the face. At the same time, the features of the back were incorporated into the sketch. This was not absolutely necessary – and for the sake of education or a tutorial it was probably not optimal – but it is the way things were done.
The front of the body was created as several extrusions and then enhanced with chamfers, edge filet, and color. The four mounting holes for the Raspberry Pi camera board were extruded into the interior face.
Next, the body was extruded along with the mounting holes for screws and a supported hole for the DC power connector.
Then the back was extruded and enhanced with the necessary chamfers and edge filet. The DC connector hole has fillet to smooth the feel.
The decorative wave pattern on the sides was done last so it would cut through all three parts.
After the body was created, the sketch that contains the shutter button hole on top and the printer, tripod mount, and power button mount on the bottom.
The shutter release hole was extruded and then chamfered slightly to aid with assembly.
The printer hole was extruded (along with the tripod mount and power button holes), then a recess for the printer bezel was extruded and finally the edges of the hole were chamfered to aid the assembly and improve the print.
The power button is fully recesses so there is an extrusion to add a cylinder of material around the button hole and a lip inside for the push button switch to mount to. The button hole has fillet to smooth the feel.
The final sketch is for the internal mounting holes of the Raspberry Pi and the battery holder. The mounting positions of the electronics need to account for the spaces occupied by the top shutter button, the front indicator LED, and the printer embedded in the bottom. Since the side walls of the body have the wave pattern, the locations of the mounting holes need to align with the thickest areas of the side material.
If you watch the animated GIF closely, you will be able to see each of results of the extrusions.
The front and back are attached to the middle using 3mm screws. The extrusions for the screws have a large recess to fit the screw head and a smaller recess for the screw shaft. The extrusions in the middle were designed to received hot pressed threaded brass inserts. The use of the threaded inserts allows for the body to be assembled and disassembled repeatedly without risk of tearing up the plastic.
The body was temporarily assembled and test fit with the electronics. The body was disassembled for finishing.
The parts were sanded using 180 and 220 grit sand paper. They received two coats of black sanding primer. They were then sanded again with 220 grit paper.
The back and middle parts received three coats of gloss black enamel.
The interior or the lens area was masked off to avoid further paint. The goal was for this to remain flat black to reduce reflections. After masking, the front received three coats of gloss light grey. As soon as the gray was cured enough, it was masked and received two coats of gloss black. (It would have been much easier to paint the grey after the black but as noted below, this failed).
The parts were wet sanded at 1000 and 1500 grit.
With only the front lens area still masked, the parts received three coats of gloss clear enamel.
The parts were wet sanded 1500 grit.
The final step was to buff and polish the parts with 3M compound and a constant speed random orbital buffer.
Fusion 360 is free for students, hobbyists, and startups. It is a full and complete CAD solution and has the ability to export to 3D printers. It does have a learning curve but the on-line tutorials and support forums are very friendly and informative.
Fusion 360 allows the user to create a timeline of edits. This enables going back and making additions or changes and then stepping forward through the subsequent extrusions and other actions.
3D printers have varying tolerances. If the printer has not been very well calibrated, it is likely the model will need to be tweaked to accommodate the dimensional accuracy of the print.
The prototype case was printed in black ABS. The front and back printed well but the middle cracked along several layers because of the relatively thin walls and the shrinkage of ABS. The working body was printed with PLA. Unfortunately, the only color on hand was pink and this complicated the finishing process. A future body print is planned using black PETG.
Painting the front was problematic. Two complete attempts were made starting with black and then masking for the grey. The grey never would cure completely it remained rubbery. It’s likely the result of the quality of the paint (Rustoleum). I high quality paint would likely eliminate this.
Briefly, the project was planned to go inside a real Brownie Hawkeye camera body but the internal space was not enough for a Raspberry Pi. The project would fit in the original camera is it were built with a Raspberry Pi Zero W.