[Espeefan]

AP, after getting my Scale Art 5th wheel mounted up today, I think I have a good idea for fitting the transmitter directly below the king pin. I won't be using a servo to unlock the pin, so I plan to make use of the space for the infrared transmitter instead. There are a couple mounting ears underneath the 5th wheel, and they are meant to use as a servo mount, but I will just machine a plate to bolt to the ears, with a hole in the center for the transmitter. No matter what angle the 5th wheel plate pivots to, the transmitter will move with it and stay perfectly aligned to the receiver, inside the king pin.

Thanks for the advice!