BOEING 737NG MCP PANEL

To build this panel I'll follow the steps shown in the case of the EFIS panel.

Elements used on the MCP panel:

Element	Qty	Notes
Paint	-	RAL 7043
Buttons	17	Omron B3F-4050
Encoders	6	CTS-288
Rotary switches	1	12 positions, 1 circuit, break before make
ON-OFF switches	3	installation diameter 6,5 mm.
MON-OFF-MON switches	1	installation diameter 6,5 mm.
Green leds	17	rectangular 5x2 mm
Resistors	17	470 ohms
7-segments displays	23	Kingbright SC36-11YWA
3 displays PCB holder	3
5 displays PCB holder	3

 

Graphic design

MCP panel consists in several layers as can be seen in the following picture:

 

Methacrylate preparation.

We proceed like with the EFIS.

 

Building the panels.

We proceed like with the EFIS. The finished pieces are shown in this picture:

 

Backlighting PCB.

I'll use 54 white high-efficiency white leds grouped in 18 groups of three with serial connection.

The building process is shown here, and the final result is:

We can paint the cards with white paint to reflect the light, and install some components: encoders (drilling a hole in the axle) and the rotary switch (with an additional axle). To avoid shortcircuits in the rear part of the PCB I install these componentes including an insulating washer as shown in the picture:

PCB for components.

The components used in the MCP panel are:

I'll use Corel Draw again to design the circuit:

We build the board in the same way:

We are ready for welding the components on the PCB. The board is ready to be mounted in the panel:

Resistors for leds are grouped on this PCB.

Panel assembly.

We'll start with the front panel, installing the MA annunciators (previously, the lateral side should be painted with black), the FD switches protections (once fitted, they must be painted with grey) and the "Disengage" switch. We can use thermal glue on the rear side to fix these elements. In the same way, we fit green leds to the back part of MA annunciators (with thermal glue too). To avoid white light lighting these annunciators, we can paint the rear of them with black paint:

Now we will work with the buttons caps. Once the two pieces that forms each button are glued, we fit the lighting leds. There are two options:

• one led and one 470 ohms resistor, or,
• two leds serial connection.

I'll use the first option (resistors are grouped on the back PCB). When this is done, we paint the lateral and the rear parts with black paint:

Don't forget to paint the V/S wheel too:

Foto

Now we are going to prepare the displays windows, fitting one or two layers of dark red transparent paper.

Front panel is finished.

Now we fit the switches on the transparent panel. Using screwed bars, we adjust the distance from the front panel:

Once the distances are checked, we take out the front panel to avoid scratches.

Then we mount the backlighting PCB parallel to the transparent panel, then the components PCB. We fix these three pieces with the selected distances between them. Then we can start cabling all the elements (inputs) to the corresponding pins. The easiest way is using connectors as shown in the picture:

Like in the case of the EFIS, we cut some wood bars to connect the buttons with the corresponding keyswitches. Then we fit the buttons in the front panel, fit the front panel with the rest. We put some termic glue to avoid space between the wood bars and the keyswitches:

Then check that every button works properly.

Now we build a cable to connect every led on the buttons with the corresponding connector on the back PCB. We can use a 40 wires flat cable, forming different groups of pairs with appropriate lenghts:

We connect this cable:

   

Now we'll fit the displays groups. Placing the front panel and using the PCB at Opencockpits this is very easy. IMPORTANT: place the displays in the holder first, then place the PCB and weld:

Displays don't cover the windows completely, so we will install something to cover the visible part:

        

Final step is cabling the displays groups to the displays-II card. We build this cable:

The final look of the panel is (move the mouse over the pictures to see different light conditions):

Last step is placing the knobs.

 

Last edition: 15.03.2006