What type of track do you have?rcrit wrote:My question is: how do you protect the IR receiver?
For a BestTrack track and I'm assuming most metal tracks the method shown on the PDT construction page should work pretty well (scroll down to the emitters/detectors section):
Basically the detectors (receivers) are mounted in a LED holder and a hole slightly smaller then the holder is drilled into the track. The holder is then pushed up thru the hole from underneath (it won't go though because of the smaller hole) and a piece of foam can be used to keep it in place. There are pictures of this method at the link above. (Clicking on the pictures should zoom them and some have additional detail in the zoom.)
Let me know if you have any questions.