27. January 2021 by Peter
In an previous post I mentioned converting an Audio Selector Panel (ASP) to the simulator. That got me hooked on converting the OEM Weather Radar panel and I also have laying around. Like the ASP it is not from B737NG – it is from an earlier version of perhaps even another model of aircraft. But the functions are the same as in the NG so it’s just a matter of wiring it up to the simulator and interfacing it – well more or less…
The inside of this panel was a bit interesting. The was of course a rotary switch to select the radar modes and a potentiometer for the GAIN. The interesting part was the Radar Tilt had a stepper motor. I was unable to figure out what the stepper motor was supposed to do.
The wiring on the rotary switch was out of this world! Beautiful curved wires that was neatly tied together. I had to replace the wiring but I tried to redo those nice bends of the wire. Remember that compared to a simulator there are many things happening inside a real aircraft panel. In this case the rotary switch had two layers and the the two layers could not be combined. Same with the potentiometer for the GAIN. It is just a simple potentiometer and a switch. But the wiring did not work with a simulator. In both cases I gutted the wiring and did my own wiring. Not it works as suppose to in a simulator.
I took out the stepper motor and 3-D printed a bracket where I could fit a potentiometer and then I designed a shaft i Fusion360 to connect the potentiometer to the gear at the end of the knob. Those were some happy 3d-printing days.
For interfacing of started using DB9 plugs. They are less prone to fall off than the normal DuPont wires that I’ve been using. Furthermore I’m using aviation plugs for the power for either the back light or the items inside the box that needs steady 5 or 12 volts.
Regarding the backlight I decided to keep the aviation bulbs that was already installed in this panel. I know it is a death sin among other sim builders to replace the real aircraft bulbs with LEDs (that is what I did with the Audio Selector Panel). But on this panel I’ve decided to keep the lightbulbs and feed them with 5v.
The conversion was more or less a bliss. Not all that difficult. Once again I strip all the components for the wires and started rewiring them myself. That seems to be the way to get things working in a simulator