Simple EFIS for the Boeing 737

Simple EFIS for the Boeing 737

When I came to the EFIS part of my Boeing 737 cockpit simulator, I found most designs difficult to use. They either required difficult sourcing of components or had a complex design.
Many DIY people are making their own dual switches, which complicates the build. Even though it is smart, I just wasn’t into that at the time 🙂

Simple EFIS cockpit design

So I decided to make my own EFIS design with the following criterias:

  • 3D printable on a small printer
  • Use simple components
  • PCB electronics inside

3D printable EFIS

The 3D design is made up of 4 sections:

  1. The main case – this can be printed with a 0.6mm nozzle if you have time considerations
  2. The front panel – this is the visible part, containing text, and should be printed with a nozzle no larger than 0.25mm
  3. The buttons – Print these with a nozzle no larger than 0.25mm
  4. The lid – can also be printed with a 0.6mm nozzle for faster printout

8x M3 countersunk screws are needed. Four for the front, and 4 for the lid.

I printed my case in PLA, color RAL7011.

EFIS PCB modules inside

As I am using SimulConn hardware boards, the case should also support an easy way of mounting these PCBs, and the best way for me to honor the small size of the case was to stack the PCBs inside.
So I mounted the three boards on top of each other using M3 spacers.

The EFIS uses 35 inputs for the buttons, and the IO INPUT board supports 16 inputs, so that required 3 PCB boards. Stacking those boards on top of each other was a close fit.

The INPUT board is connected to the flight simulator through the Extension board, so I made a hole in the back of the case to let the ribbon cables pass.

To mount the PCBs, 8x M3 spacers and 4x M3 screws are needed.

Using simple components

To comply with simple components, I changed the design of MINS and BARO, and converted them into two switches instead of one dual switch.

And for easier mounting and soldering of the switches, I opted for the non-PCB mounted pushbuttons.

The following components are needed:

All components are inexpensive. Click each product above to get inspiration for sourcing.

The switches are mounted in the main case, so the buttons and the front goes on top of this. Really easy to mount.

EFIS assembly