This is a direct continuation of PART FOUR, picking up where I left off, with the design and fabrication of a suitable enclosure for the flight unit.
Using the Sketchup web package (free online here) I designed the enclosure to house the SSL, see Figure 1.
I procured a Flashforge Creator 3 Pro 3D printer to fabricate the enclosure. This choice was driven by the desire to print in polycarbonate (filament type “PC”) — for strength — as well as polylactic acid (filament type “PLA”) — for prototyping. The printer is shown in Figure 2.
Printing the enclosure components
Given the complexity of the structure — with its various cutaways, internal shelves, etc — it turned out to be difficult to print the enclosure as a single monolithic structure. After a few failed attempts, I opted instead to split the job into multiple components which could then be assembled together later. Figure 3 shows the collection of individually printed components, pre-assembly.
Figure 4 shows the enclosure partially assembled with the internal SSL components visible.
Figure 5 shows the fully-assembled SSL with the enclosure components bonded together using epoxy resin. For comparison, the legacy fatigue meter is displayed on the right..
Figure 6 shows the SSL installed in the Bulldog aircraft in the location where the legacy fatigue meter is ordinarily installed. The new instrument is a plug-and-play replacement of the legacy instrument. No changes whatsoever are required on the aircraft.
In summary, the following steps remain from the original list in PART ONE:
- Make any final adjustments to the software based on further flight tests — ideally across the full dynamic envelope of the fatigue meter (+6g, -1.5g) and against different legacy instruments (i.e., rather than just the single instrument used in all tests so far).
- Submit for mod approval via the LAA for installation on my Permit-to-fly Bulldog.
- Calibrate the SSL via the ground-test company (if required for the mod approval process). This may be required to reach the extreme ranges (+6g, -1.5g) if unable to achieve those in flight.