Progress update on the F-104 cockpit simulator I’ve been building.

Some bigger pieces finally came together this week: the attitude indicator redesign works, the cockpit stand is finished, and I had to tear apart the ejection seat to replace the adjustment motor.

Attitude indicator redesign

The first version of the attitude indicator used servos, but I wasn’t really happy with the performance. The resolution and movement just didn’t feel smooth enough for an instrument that should move very precisely.

So I redesigned it to use stepper motors instead, which gives much better positional control when it’s driven from simulator data.

That solved one problem but created another.

The roll axis rotates continuously, which means the wires would eventually twist themselves up.

The fix was adding a slip ring, which lets electrical connections pass through a rotating joint.

So now the roll indicator can spin 360° forever, no more twisted wires.

Cockpit stand and setup

I also finished building the stand for the cockpit.

The frame is now welded together and the cockpit is mounted on it. I installed the screens, mounted the PC that will run the simulator, and added a ladder to make getting in and out easier.

For the first time it actually looks like a simulator setup instead of a pile of aircraft parts scattered around the workshop.

The ejection seat adventure

The cockpit has an original Martin-Baker Mk7 ejection seat, and I decided to modify the seat adjustment system.

Removing it from the cockpit and disassembling it was… an experience.

Everything about it is incredibly heavy and massively overbuilt. These things were clearly not designed to be casually taken apart in a workshop.

Inside the seat there’s a small 400 Hz single-phase 60 W motor that drives the height adjustment.

The catch is that it’s rated for 1 minute of operation followed by 9 minutes of cooldown.

That’s fine in a real aircraft where the pilot adjusts the seat once before flight.
But for a simulator where lots of people will adjust the seat during demos, that duty cycle isn’t ideal.

So I replaced it with a 24 V DC 200 W motor, which should handle frequent adjustments much better.

Right now the seat is still partially disassembled while I adapt the mechanism to the new motor.

Current progress

• Attitude indicator redesigned with stepper motors
• Slip ring added so the roll axis can rotate infinitely
• Cockpit stand welded and assembled
• Screens, ladder and simulator PC installed
• Ejection seat removed and disassembled
• Seat motor replaced (400 Hz 60 W → 24 V 200 W)

Next step is finishing the instrument mechanisms and connecting everything to the simulator data.

If anyone here has experience driving real aircraft gauges with stepper motors, I’d love to hear what hardware or drivers you used.

Also curious has anyone here restored vintage aviation hardware for a simulator?
How did you balance keeping things original vs making them practical for regular use?

More updates soon ✈️