Creating Joystick help

I have been searching on Google for a while an I could not find any existing joystick that would allow me to control up to 4 engines on an aircraft to use in my flight simulator. I found a few that would allow me to control 2 engines, but i don't see any way to connect two of them to one computer and have them both work. I am left with but one option, I have to build one myself. This is where the forum comes in, because of my complete inability to program or interface any complexly digital component, I was hoping that someone would be able to help me try and make this work.

I would be willing to use any micro-controller that you specify, but it has to be able to select a range of engines from 1, 2, or 4. this would be done using 3 switches to specify how many engines are on the plane that I'm flying. switch 1 would either be 1 engine, or all engines selected (since it's impossible for a plane to fly with no engine) the second switch would select if there are 2 engines and the same for switch 3.

If nobody is willing to do the programing portion for me, could you at least give me a link to some documents that would show me how?

Thanks; Vince

If you are writing the flight sim then you could use something like the UBW. This will enable you to read 4 potentiometers via USB.

Mike.

4 engines on a plane? why would you need to control a single side pair separately?

doggy__ said:

4 engines on a plane? why would you need to control a single side pair separately?

Click to expand...

On multi-engined planes you have separate throttle controls, it's far more versatile - and pretty important if you lose an engine.

However, I don't think they are controlled by joystick anyway?.

ya but whats the diff if you put 99% on engine 1 and 1% on engine2 OR if you put 50% on both engines = same output torque

considering they are both on the same wing(to me it kinda looks like parallel currents since they torque the same wing)?

Being able to control multiple engines would allow me to make hair pin turns while taxing which is a huge convenience, if i only have 2 engines at 50% and one at 99% and 1% then I'm not running at full power. I'm not actually creating the game that this is going to work with, the game has already been made and I just thought it would be really cool to build a flight simulator that would increase the realism. The site for the company that made the game can be found here: HiTech Creations - Aces High
The motion platform as well as the force feedback portion of the simulator is a copied design, and slightly modified. The link to the site can be found here: Simprojects.nl

The joystick in question would need to be able to recognize not only the 4 engines, but also have some way to select how many engines there are, as well as sense ailerons, elevator, and rudder positions. Otherwise that USB bit whacker would be perfect.

doggy__ said:

ya but whats the diff if you put 99% on engine 1 and 1% on engine2 OR if you put 50% on both engines = same output torque

considering they are both on the same wing(to me it kinda looks like parallel currents since they torque the same wing)?

Click to expand...

Well first, it's a flight simulator. So presumably he wants it to be similar to a real plane (to deal with nasty situtations like engine flame out and damage I presume being the most important thing).
http://en.wikipedia.org/wiki/Thrust_lever

Also, 99% throttle on engine one and 1% throttle on engine two is NOT the same as 50% on both engines. For a fixed propeller, static airspeed increases linearily with RPM, but thrust (aka torque) increases by the squared of RPM. Then there's also the fact that the engine's torque vs RPM curve is also not linear.

But independent engine control is required for engine failures. It gives you the ability to shut off the engine that's failing so it doesn't burst into flames or break apart and allows you to adjust for the yaw imbalance produced by an assymetrical engine failure. Any engine failing makes an imbalance in the yaw of the plane because one side is now producing more thrust. You can correct it with more rudder or by reducing the throttle on the good side which is producing more thrust and/or increasing the throttle on the remaining engine on the bad side which is now producing less thrust. There's also the fact that outboard engines have a longer moment arm than inboard engines so to get the total maximum possible thrust out of all remaining engines without the yaw imbalance being too bad, you'd have to shut the bad engine off, give the lone engine more throttle while reducing the throttle of the inboard engine on the good side, and reducing the throttle of the outboard engine on the good side even more (since it has a longer moment arm). You can't always rely on the rudder...you have to be flying fast enough for it to have sufficient authority to fight the yaw produced by unbalanced engines.

If you don't deal with the yaw imbalance and let your airspeed drops too much then the rudder is no longer effective enough to balance out the yaw from an imbalance due to assymetrical engine failure and you can go into a spin as you crash to the ground. I've had that happen to me in a simulator which is why I don't like multi-engine planes unless they are mounted behind each other, but they have their own problems like reduced efficiency. Took me a while to figure out why I could fly just fine when an engine died but as soon as I went in to land I spun out of control and crashed. You usually can't simply shut off the engine directly opposite of the failed engine to correct for the yaw imbalance and keep on flying since most multi-engine planes have those engines because they need them to fly rather than for redundancy (and that obviously doesn't work if you're in a battlezone and the inboard engine one side and the outboard engine on the other side has died).

I was looking for something similar to for my RC transmitter. But in vain. He might have more luck since I assume his can be much bigger.

Is this to your liking?
http://search.digikey.com/scripts/DkSearch/dksus.dll?Cat=1114837&k=apem bar
Not cheap x4 though...I find all joystick components are vastly overpriced though.

You are hooking these to a computer? Why can't you just hook up two double thrust levers via two USB ports?

I wasn't a hundred percent sure if i could hook 2 double thrusters to the computer at the same time and have them work with that game. The joystick that I'm using now (a Saitek ST90 Pro) only has on throttle function. I can control each engine independently, but I have to take my hand off the stick which is not fun when your being shot at . I would have to ask the game creators if hooking 2 doubles together would work or not, otherwise I'm left with my original dilemma of rigging multiple 555s to manipulate a keyboard, which would take a lot of time and would make the whole simulator about 10 times more complex.

How would manipulating a keyboard help? I ask because a keyboard could be mimicked by a (USB) pic chip hooked up to your throttle controls. The pic could send any keyboard combination in response to the controls.

Mike.

If I try to manipulate the controls through the keyboard I would need some way to stop the throttle for other commands like the gears, and flaps. I would still have the same problem if I used a USB version. The best way to go about that problem would be to disable the throttle untill they are moved. That would take way too long. The keyboard command for selecting 1 engine is Shift key + eng #, to select all it would be Crtl + E. I'm sending an email to the game designers to see if the double throttle would work. Hopefully they will get back to me soon, even if they haven't gotten a conformation email for their forum (it's been 4 months).

What I meant was that a pic could appear to the PC like a second keyboard and when a throttle is moved it would send shift + eng# then a number. If this sequence left the keyboard in an unknown state then switches could be added for the other functions therefore eliminating the need to ever touch the original keyboard.

Mike.