It will be quite a while before I need them, but I have been thinking about what type of instruments I will need. Of course, for an experimental aircraft you don't legally need any instruments. My current 'want' list consists of Tach, Airspeed, Altimeter, Oil Temp, Oil Pressure, Fuel, Turn Coordinator and/or slip indicator, and a magnetic compass. My smart phone can be used for navigation, and a handheld for communication. There is no need to pay for TSO'd gauges. Non-TSO'd, from what I have seen, are $150 to $200 (USA) each. What are the alternatives? There are of course, the digital instruments that use some kind of LED/LCD display. Also apps that run on a smartphone or notepad. But for those who would prefer "real" steam gauges, there is an alternative. I guess there are a class of people even more crazed than us HBA'rs. There are those who build their own flight simulators, and some of them use quite realistic looking simulated instruments. One supplier is Sea Gull Simulation. And Mike's Flight Deck tells you how to build your own, which can use servos, synchro motors, or automotive type air-core gauges. Mike's web sight even shows how to build your own air-core gauges from scratch. What I have in the back of my mind is one or more microchip computers with some of the analog sensor chips. The microchips would process the analog inputs and display the results on the gauges. Most of the Flight Sim gauges I have looked at use some kind of digital protocol (such as CAN bus). I guess you could do that if you wished, but I think that would add unnecessary complexity. Just process the inputs and control the gauges directly. Most all microchips currently available would have more than enough power for the task, and many of them already have the necessary analog outputs and inputs. I haven't looked into it any further than this, but my guess is that, for someone conversant in microchips, it should be much less expensive than even a set of non-TSO gauges. Has anyone else thought of this idea?