HSI - Horizontal Situation Indicator

The first thing I ever tried to construct for my simulator was an HSI. I knew early on that I didn't just want to have all my instruments be LCD screens, I wanted real mechanical ones.

Therefore I started constructing my own and bought my first 3D printer for it.

At some point the instrument started seeming really daunting and getting more complex than I envisioned it originally. I wanted to know how an actual HSI is constructed, but couldn't find any pictures of its mechanics.

I kept looking around for old HSIs on ebay until I eventually found one that seemed to match what I was constructing. An AF/A24J-1, the HSI of an F-4 Phantom, which I quickly bought for just shy of 200€.

My plan wasn't to use this instrument, I still wanted to build my own, but wanted to reverse engineer the original to get some inspiration from it.