I already finished the Attitude Indicator. I plan to do a more detailed writeup and a video on this one, so for now, only to images.

From the front, it looks more or less like any other DIY Attitude Indicator. However, while it is almost never needed during normal flight, I have always disliked the fact that most DIY Attitude Indicators have a roll limit to avoid tangling the wires. One solution could be to use a slip ring for the cables of the pitch motor or servo. However, my idea was to over-engineer the entire thing by designing it with coaxial motor shafts, placing both motors for the two axes outside the moving cage.

The truly challenging part was getting the software to work.

Over the last two weeks, I’ve been designing and building an HSI from scratch. I couldn’t find any DIY versions of an HSI. Since a typical HSI requires (at least) five axes to operate (six in my case), I quickly decided to keep the mechanics as simple as possible and use a slip ring to route the wires for the VOR part out of the moving cage.

However, the whole thing is still extremely complicated and tightly packed. I’ve just finished the first prototype to the point where I can start testing some of the motors. That’s when I learned that this thing won’t be working as planned anytime soon. There’s far too much friction in all the moving parts (even with grease), and there’s not enough space to fit large ring bearings into the design.

So, for now, it’s back to the drawing board.

See you next year…