You could do such a thing... but one potential problem comes to mind. The touchscreen calibration routines typically involve having your display put a marker up on the screen, and having you touch it... move the marker and repeat the process. Usually the minimum is 4 points, and sometimes there is an option to go for quite a few more than that. You could, in theory, make a calibration template to temporarily place under or over the overlay... but you would have to come up with a good system for indexing it in order to get consistent results... plus it would be a matter of trial and error to get your marks for where to touch placed properly. You would also want good indexing for your control templates that you make up. IMHO, you have fewer headaches just getting an el cheapo monitor to put the overlay on... even if you had to get a low end video card to provide the video to it (remember... nothing says you have to run that screen at 1080p resolution).

Also, keep in mind that Helios, (and I think TouchBuddy) can be run on another machine on the same Local Area Network... if you have another (probably older) PC laying around unused, you could put an overlay on a display hooked up to it, and use that to provide inputs to your sim machine.

the daughter board is a small board that you connect the overlay to, then you connect the DB to your PC via USB.




Also, This maybe Cheaper if a Guide Exists:

(edit: link to guide: Link to guide )

Another potentially low cost alternative (especially if your computer already has a suitable Bluetooth transceiver and software stack) is a Wiimote and a homemade IR LED glove. You can find all sorts of videos on Youtube (Search on "Wiimote whiteboard"). Basically, you're linking the Wiimote to your PC via Bluetooth, using the Wiimote's Infrared camera to track the light from an Infrared LED via some freebie software. When the LED is lit up, it is treated as a left mouse button click. You can use it with a monitor, a projection screen, or a piece of paper (ie. your printed template). As I understand it, it is possible to use more than one Wiimote (don't hold me to that)... if so, you could have more than one panel of controls.

That is really cool! Only works with clickable cockpits so RoF or IL2 46 are out but damn cool for the rest!

I'd never seen that before... time to research a bit,
Cheers,
C_G