How To Build Your Own Cockpit

by Kev Saker

INTRODUCTION

I think you will agree that the flight sim world is moving forward at an incredible pace. It is now possible to build a flight simulator that would compete with many professional systems in use today. There is a firm in the UK that can supply a full motion platform and a visual system to match. This linked to say six networked machines would provide the ultimate flight sim experience. Needless to say this will cost a lot of cash. I believe that most people find it hard to keep one system up to date with the latest graphics cards, chips, etc.

So, I would like to show in this short article that it is possible with nothing more than time, enthusiasm, and a little cash to build a realistic and capable flight simulator based on a single P.C. system. Also, this same P.C. will still be available for other tasks such as e-mail, games etc.

I will try to describe how I built my sim and what it is capable of doing. My simulator is a fixed base cockpit mock-up comprising left seat, centre consul, overhead system panel, flight controls and a simple seat motion system. The sim is modelled on the Boeing 757-200 twin-jet transport.

FLIGHT CONTROLS

All flight controls work from two stripped down P.C. joysticks. First joystick: elevator, aileron, gear and toe brakes. Second joystick: throttle, rudder, nose wheel steering and flaps up, flaps down.

Secondary flight controls, speed brakes, reverse thrust, parking brake and elevator trim all work through a simple computer interface which I will describe later. Finally, all radios, ADF, VOR 1, VOR 2, COM 1 and transponder along with all autopilot functions and engine start/stop work through the computer interface.

Naturally I did not want a keyboard in the flight simulator; I wanted all the functions to be controlled from the correct switch panel etc. There are now two ways you can do this, firstly I will describe my way.

My computer has two keyboards, the first for normal use, the second is used solely by the sim. All you need is a data switcher, (the type used for running two printers from one computer). This enables you to switch between normal keyboard and the flight simulator. The second keyboard is shut away in a cabinet. Over the keyboard there is a plastic plate with 102 holes drilled in it which correspond to all the keys on the keyboard. On this plate are attached small keyswitch solenoids with plastic rods that go down and rest on each key. I use approximately 35 solenoids to control all the switched functions on Microsoft Flight Sim 98. By also controlling the ctrl key and or the shift key with a solenoid you can double the number of functions controlled.

Just about any type of small low voltage solenoid can be used; model railway points controllers for example are very inexpensive, The solenoids get their power from two model railway type 12volt transformers.

Now we come to the interesting bit...The one thing that FS98 lacks is any systems panel simulation, generators, hydraulics, A.P.U. etc. So, if we run the power supply through the generator control panel switches to the solenoids the transformers now become the aircraft's engine driven generators. The generators will not supply power unless the switch panels are correctly set.

All the solenoids can be connected up in the same way by running them through the various systems panels. This makes the simulator much more realistic as you now need to go through all the checklists to ensure every thing will work, as it should.

This system is very simple and inexpensive to build, I have used it on two sims over the last few years and it has proved very reliable and could be used on any type of flight sim program. Because of the way keyboards are made the solenoids do not require any return springs etc. I have included a photo of my interface cabinet. From the bottom this shows the keyboard and the solenoid tray, above you can see the two transformers that power the solenoids and a single 12 volt transformer that powers the cockpit lights, next to that is a sound system amplifier.

The top shelf has a small tape deck, which has pre-recorded verbal checklists. This is useful, for example, when you taxi out for take off. Just flick a switch on the left side panel and you will hear the relevant checklists. Finally, a transformer that powers the seat motion system and the auto throttle.

The second method is now available commercially. It is called an EPIC device. This is a card that goes in a spare slot on your computer's motherboard and has terminals that you can connect all your cockpit switches to. This will cost a bit more than my system but it is a good alternative if you don't fancy trying my idea. Details can be obtained from rrelect@cris.com Tel- (301) 699-5277.

VISUAL SYSTEM

The visuals for my sim are provided by a 25" Fresnel lens. I have one 21" monitor with my computer on a desk next to my sim (see photo). This desktop extends along the front of the sim, so when I wish to use the simulator I flick the changeover switch for the keyboard and slide the monitor along the desktop to the Fresnel lens. The lens gives me the captain's flight instrument panel and the forward view; the only draw back of this system is that you do need a large monitor, although I made do with a 17-inch for some time. (Photo shows 17-inch monitor.) The cockpit structure is made of wood but all areas that you might touch including the floor are covered with very thin Alum sheet. All system panels are made from plasticard which can be obtained from model shops etc. All the lettering on the panels is done using Lettereset transfers. Knobs, switches and micro switches can be obtained from electronics stores etc. The flight controls are all hand made. The yoke is a piece of copper pipe bent and welded to get the shape. Pipe is good because its strong and hollow, which is useful when you come to wire up the switches (trim, mike button and autopilot cut out). The pipe is covered with car body repair filler paste, which is then sanded to shape. This takes time and it is necessary to fill and sand repeatedly until you get the shape you want. If you use this method you can model a very accurate yoke for any aircraft. The throttles and rudder pedals are made from alum sheet. All flight controls are then connected up to the potentiometers from the stripped down joysticks. Of course it is possible to use commercially available yokes and rudder pedal set-ups if you prefer.

Recently I have fitted a tracker ball on the left side console next to the nose wheel steering tiller. This is used to set the altimeter QNH and adjust the rate of climb on the autopilot M.C.P. panel. If anybody has a keyboard shortcut for these two functions I would love to hear from them.

RADIOS

Changing radio frequency on flight sim using a keyboard can be a bit of a pain; my idea is simple and makes it much easier. Each radio panel has a standby button and a single rotary knob. To change a frequency you just press the standby button and rotate the knob to set the frequency. It works like this: the standby button, for example, on the com panel is connected to a solenoid over the C key. The rotary knob has two micro switches under the panel, one for rotate left, one for rotate right. These are connected to solenoids over the + and - keys. The beauty of this is that all the radios in flight sim use the +and - keys for changing frequency. This means you only need one solenoid for each radio.

SEAT MOTION

I will now try and describe how I built the seat motion system. For a long time I have wanted to build a simple motion system, in particular some form of effect that would cause the seat to vibrate and bounce around on touchdown. On the back of my seat pan there is a metal arm which has a low voltage motor driving a small flywheel with an off centre weight attached. This is all enclosed in a box. By adjusting the voltage to the motor this produces some interesting effects, a kind of a shake rattle and roll! Now, the hard bit is getting something to drive this. The answer like most things was simple: a disco sound to light unit, only not sound to light but sound to a relay which controls the motor. These units are cheap to make or you could buy them from a music store ready built.

I then changed the wave file in flight sim from a screech on touchdown to a deep rumble. This sets off the motion system on touchdown, and also picks up other sounds and gives the odd twitch of movement which adds to the effect. For example, when you raise or lower the gear, select reverse thrust or crash all produce different effects.

I believe you can get thunder sounds on some programs this will produce a turbulence effect too. I have recently fitted a simple autothrottle to the sim. When this is engaged if you pull the stick back the throttles will advance, when you push forward they will return to idle, also a simple EPR setting for reduced thrust takeoffs.

WHAT IT COSTS

People have asked me how much I have spent on the project. It is difficult to say but not including the computer approx. £500 would about cover it. My first simulator was based on an F4 Phantom. This was built in the same way as above, however I included a small air compressor which, when you heaved back on the stick would inflate a G-suit I obtained from a surplus stall at an air show. I have included two photos of the F-4.

That about covers it for the moment. If I can help in any way with your simulator don't hesitate to contact me. If you have built a sim I would like to hear from you, it would be good if we can pool all ideas. Any questions or suggestions please contact me at kevin.saker@virgin.net

The Fresnel lens can be obtained from "R.C. Simulations" http://www.rcsimulations.com or e-mail Mary@rcsimulations.com

I would dearly like to get a copy of a flight manual or extracts from one for the Boeing 757-200, if you can help please contact me.

Finally, I would just like to say thanks to FlightSim.Com for allowing me to share my ideas with you.

Bye for now,

Kev Saker
Southport,
U.K.