Mounting the emitter is the most critical part of the whole installation. The emitter drops an infrared curtain in front of the display which, when intercepted with your finger, signals a touch event. The interaction surface must be absolutely flat and stable (hanging canvas won't work).
You can follow these steps carefully to have a perfect installation.
1) Position emitter 1-2 inches above the projection image and mark the screw holes with pen.
2) Drill four small holes on the marked position with a driller.
3) Apply the yellow double sided tape on the emitter and peel off the protection film.
4) Cut a small piece of paper (roughly 1x1 cm, name card thickness)
5) Paste emitter with four screw holes carefully aligned.
6) Put the small white markers at the corners as marked.
7) Tilt the emitter slightly in or out and you should see a whiteband moving up and down inside the greenbox. Tilt it until the white band just disappears and you should see two cross hairs on the markers.
8) Wedge the emitter with a small piece of paper (about a namecard thickness)
9) Start screwing the emitters carefully. Always check if the cross hairs are still there. If not, undo what you did. You can disconnect the power to screw the top right screw. And recalibrate Ubi to switch on the emitter.
10) Verify the emitter is placed properly by moving your finger across the entire display.
11) Remove the markers and the wedge paper and click continue to finish the rest of the setup.