HOW TO BUILD A B-737 300/800 THROTTLE QUADRANT By Francisco Gago Date: February, 3rd, 2.004

1.- INTRODUCTION If you are interested to give a more realistic touch on your Flight Sim, I would to recommend you this make: for me, it was definitively a change. The heard is an old Saitek X-35 Joystick, which comes in two parts: Axis Lever and Thrust Lever, connected both by mean of a DB15 plug, and from the Axis Lever to the PC by a USB conector. Then, I broke the Thrust Lever (Rest Peacefully) in order to convert it in the actual Pedestal with a lot of Programming Buttons: it is without any doubt the easiest way. The main drawing was done by my partner of the Spanish Cockpit Builders Group Builders, http://groups.yahoo.com/group/construccion_cabinas/ ,Pedro Bibiloni, and I added several views and details of single parts and are available in the download section of my Web page http://personal.telefonica.terra.es/web/fagase/cabina/descargas_en.htm

The design is thought for the DYIérs, and special tools, materials or hands (yours, of course) are not needed. The materials are very easy to get from your local DIY Store, and basically the parts are made from wood, Plywood, steel and alluminium. The tools are just a drill machine, files and a jag machine.The parts were made using prints from the drawings as templates.

The functions are: thrust and reverse levers for each engine, flaps, elevator trim, fuel valves, Aerodinamic Brake and Park Brake.

2.- BUILDING

About the drawings, they are in Autocad *.dwg format. As an alternative to this Payware Software, there is available a

drawing viewer Freeware program which is called Volo View Express, downloadable for example in

http://www.cadvisionsl.com/voloview.php

I used them as templates for sagging the parts: they are in scale 1:1 ready to print in DINA4 sheetpapers, by zoomming on each part. In order to check the printing one measurement is added on each part.

The reference nrs. indicated in the drawings below to the texts in the below

attached pictures.

The first step is to break (after praying a bit) the Joystick, taking notes of the colour wiring of the buttons and potentiometers. It is possible to use analog to digital converters too, but it was not my case.

I begun building the Throttle Levers. They are based in the building process of the french builder Claude Kieffer, who has a very nice and detailed explanation in his web: http://projetb777.free.fr For the flaps and elevator trim, I took his concepts too.

The next step is to make the main frame sections. I recommend to drill first the main hole to Diam.8 in order to sand all these parts together as a block. The hard plywood I used is from Aeromodellerkraft, including the 0,8 thick sheet for covering all the rounded surfaces, as stated in the pictures.

With all the M8 bars in position, is very easy to set all the frame sections by adjusting the nuts. During the progress of the building of the different systems we will have to assembly and disassembly several times. I recommend you to proceed in steps: 1st Assembly and adjustment of the Throttle Levers, 2nd Flaps lever, 3rd Aerodynamic Brake Lever, 4th Fuel Valves Levers, 5th Parking Brake Lever, and 6th Elevator Trim.

Because this construction is for DIYérs I thought that It was stupid to draw every single part of each system, because with the tools we use we are not able to get enough accuracy: with the help of the pictures I think that it is enough and the best.

For finishing, I coated with two layers of primer, and another two with Spray Paint, colour code RAL 7001 (light grey).

3.- MAPPING THE THRUST AXES

The Reverse Function works by mean of a microswitch for each engine: the first test I did assigning each one to its engine by mean of the menu of the FS, allocation F2, but as the FS must first have selected a engine, by mean of the function E1 or E2 (if not, F2 works on both engines simultaneously) I found a solution mapping the axes by using the function of the FSUIPC module, but with a simple trick: with the engine handle to the idle position, the potentiometer is not in the

end position, but something turned. Then each switch what it makes is to bypass the rest of potentiometer that is left between the idle position of the handle and the end of the potentiometer, mapping the reverse position of the axis with the switch activated. For the maximum position, directly I could map the axis without to have the potentiometer to its maximum position: thus it is not necessary to worry about the gearing between the handle and the potentiometer.

4.- COMENTED PICTURES:

If you need higher resolution, you may obtain them at: http://personal.telefonica.terra.es/web/fagase/cabina/fotos_pedestal_en.htm

Details about he single components of the Flaps system.

Assembly picture of flaps system.

Assembly of the flaps system.

Assembly of Park Brake system. Shown in its OFF position, this was the solution I found in order to lock the lever in both positions, by mean of a cam built from plywood. Below, the Lever in ON position:

Thrust Levers coming in shape.

Thrust with Reverse Levers view.

Main Frame Sections details, testing the assembly. At the drawings file, there is a view with the dimensions between sections to set the positions.

Showing the Trim Discriminator of the way of movement. Inspired in Claude Kieffer ´s concept, who has a very nice and detailed explanation in his web: http://projetb777.free.fr (he uses clamps instead). The Trim Notch Cam is not shown, comes in front of, for better view. The bycicle chain and sprockets are mounted on both sides of the console, for transmiting the Wheel movement of the Elevator Trim to both sides. It is easy , and runs very well.Otherwise, it would be necessary to increase the diameter of the main shaft, in order to do this movement by mean of a concentric bar (pipes), and special tooling may be needed: with this solution not at all. See already painted the afterwards viewed surfaces: this makes easier the final painting.

Viewed from the botton, with almost all the components in place:just missing the chain/sprockets at the botton. See that all the main systems, includind the Fuel Valve Levers, are turning through the main M8 Shaft. Then, care is needed for not increasing too much the length of the Main Shaft: just cut in halfs the fixed M8 nuts (cut the thickness).

Above, acouple of views.

Covering details.

After sanding a couple of hours, I got a good shape for the Trim Wheels.

Final stage: the springs are just finishing details.

And the best is that IT RUNS!!!!!!!! Francisco Gago fcogago@telefonica.net http://personal.telefonica.terra.es/web/fagase/cabina/