My generic GA cockpit

[gfesim]

Hi,

my cockpit runs on X-Plane 10, a Windows machine drives the panel and the flight model, two more Linux workstations drive the outside front, left and right views. A laptop is used as instructor station and an iPad serves as an additional navigation device.
The pedals are off-the-shelf (made by Flightlink), the yoke is from PFC, converted to USB and equipped with additional toggle and ignition switches. (BTW, this will be for sale soon, as I now built a force-feedback yoke (not yet on the photos)).
As I regularly fly various GA planes, primarily C172, PA28, Mooney and Cirrus, with standard six and glass panels, I never planned to mimic a specific panel or aircraft, but rather a generic one.
That’s why I chose the concept of mounting the panel direct onto two standard 22“ monitors. The idea is that the panel can easily be removed and replaced with another one. Currently I just fly the analog gauges panel, but the G1000 is in the planning phase.




The challenge here is that every part has to be quite flat. The left side of the panel is 6mm thick, the right side just 3mm. The encoders on the gauges are Alps, and they are wired on the backside of the panel where I milled grooves for running some ribbon cables.




The radios, intercom, autopilot, transponder etc. are all custom built.
Here is a closeup of the transponder unit.
BTW, the transponder is fully functional in all features like altitude monitor, timer, night mode etc. I’ve programmed it as a plugin for the X-Plane community and it is a free download there.



Hope you like what you see, there is more to come.

Thanks for watching
Gerald

[Matt Olieman]

Very nicely done.

[vorcowra]

That is a very nicely thought out and carefully executed panel . Superb work. Thanks for taking the time to share your work.

[gfesim]

Hi,
thanks for the friendly comments.

Today I’d like to show off my GNS 430 that I built for mounting into my on-screen panel.
Like with my whole panel, I don’t use separate display modules or LED digits, but all display is on two 22“ screens where all the panel instruments are sitting on. See my initial post.
The instrument has been designed closely to the original device in terms of dimensions, button size and tactile feedback, so I can use it regularly for honing my instrument flying skills. Bezel outline and cutout dimensions are accurate with a tolerance of about 0.5 mm.
A detailed 3D Sketchup drawing and other building resources are available in a package in the download section.



The device is based on a frame, milled from 10mm PVC, a faceplate, 4mm thick and a plexiglass display cover. On the backside there is a breadboard for the tact switches and encoders.



The Sketchup drawing has several layers, one for each part, plus a dimensions layer.
For those familiar with CNC milling, I provide some G-Code scripts for the individual cutouts. The chamfer on the display cutout is milled line by line, with a 0.05 or 0.1 mm displacement. A bit difficult to machine, no guarantee that it‘ll work for you right away. These scripts are quite basic, as my CNC programming skills are limited, so please cross-check before you start.



An alternative approach would of course be 3D printing the whole thing. But regular FDM printing is too low resolution for my demands, and SLS or other sintering processing I feel is still too expensive for a hobby.



The buttons are WIMA capacitors, which I cut down and painted. They are rectangular, where the original buttons are slightly round-shaped, but they match perfectly in size (+/- 0.2mm)


The tactile switches are Alps SKRG. Of course any tact switches with similar operating force will do, the length of the buttons may have to be adjusted.
It is important to note that the switches and all other components are mounted on the copper side of the breadboard. This doesn’t make soldering easier, but for a screen mounted device it is crucial that there are no lead wires that protrude on the backside.


The volume potentiometers are Alps as well. Any PCB mounted potentiometer with push-button on the axis will do, as long as the height matches.
The dual concentric rotary switches are ELMA E37 encoders. They are hard to find, not exactly cheap, but provide the best haptic feedback that I could find on the market. Mouser, Digikey, Farnell don’t stock them, but Leo Bodnar supplies them (and ELMA obviously if you buy at least ten). The center axis has been cut off a few millimeters to match original units knob heights.
Both the potentiometer and encoders are soldered and wired on the copper side. The lead wires need to be cut down as mentioned above.



Wiring is done with very thin insulated copper wire (Verowire). I think next time I would design a PCB for this, as the wiring job can become really annoying.
The USB interface is a custom made PCB with standard SMD parts placed around the Microchip PIC 18F4550 processor. As a standard HID device, there are no drivers needed so it works with any OS. Basically it’s just an I/O board with 24 button inputs, 4 encoder inputs and 2 analog inputs for the volume potentiometers. What it sets apart from most other I/O boards, is its small footprint and a height of just 2.8mm. Of course any other interface will do, but if it is larger, you might need to place it outside of the instrument.
The PCB layout and a hex file with the firmware is included in the download package. A basic programmer will be required, as the firmware currently doesn’t contain a bootloader. If anyone is interested in the details of this I/O board, I will post that here.



Finally lettering is with those super thin foils that the scale model builders use. The ones that you put into water, wait until they separate from the paper and then you carefully slide them onto the object. No idea how they’re called though.
I use the RealityXP software which is available for FSX and X-Plane. Of course any software that has accurate display size and aspect ratio will do.

So far I’m quite happy with it, but as always, there is still things left to improve:

• The push-buttons should be curved and of some softer (rubber) material. This will be an upcoming project
• The knobs should be grooved on the complete length
• Lettering should be backlighted. Not so relevant for me as I do little night flying
• COM Volume potentiometer should have a radial detent for switch-on (haven’t yet found such type with acceptable dimensions). I mimic that by software
• The ambient light sensor that in the original device controls the LCD backlight is inoperative. Preparations are made to place a photosensor on the circuit board and connect it to an analog input. Needs a software controllable display light in the GPS software though. My GTX328 transponder has that feature built in.

If someone is interested to have a closer look, everything needed to build this device is packaged in a ZIP file that I placed in the Download section.
It contains:

• Sketchup 8 drawing with all the physical details and dimensions (.SKP files)
• G-Code scripts for CNC milling most of the parts (.TXT files)
• Schematic and PCB layout for the USB board in Target file format (Target PCB layout software is available free of charge) (.3001 file)
• HEX file with the compiled C Code firmware (HEX file)

Fly safe !
Gerald

[vorcowra]

Truly extraordinary. One cannot but admire the attention to detail and the pursuit of excellence.