USB Flight Sim Throttle Quadrant

[grasshopper]

Hi all, This is my first post, and I did try a search before deciding to go ahead and ask for advice on my idea of creating a home flight simulator throttle quadrant that will work with a standard USB conector.

For some reason all the affordable flight simulation throttle quadrants currently on the market are manufactured with extremely fragile components, and bear only a passing resemblance to the real thing. Right now I use a GoFlight TQ6 throttle quadrant for my all-jet flight sim sessions, and despite the functionality of the product, I have felt let down by the short life-span of its build quality. As an example, the speed-brake lever quit working soon after I bought the unit, forcing me back to using the "/" character on the keyboard.

Cutting to the chase, I wouldn't be inclined to shell out $1200 for a realistic Boeing-style throttle quadrant from a vendor such as VRaircraft even if I could afford one, and so have decided to put together one of my own, with the help of a buddy who owns a small machine shop, and will construct the throttles, thrust reversers, flaps and speedbrake lever array, along their points of rotary articulation about pivot pins inside the quadrant housing.

My question here regards the circuitry that will be required to interface up my throttle quadrant to the computer via a standard USB cable. My vague plan at the moment is to connect rotary 100K-ohm potentiometers to all levers at their points of articulation , and to feed the output from those pots into a commercially available USB interface chip, which should process the signals from each lever to enable the assignment and callibration of those variables within the Microsoft Flight Simulator 2004 "settings" page.

I haven't dabbled in electronics prototyping for many moons now, and I would sure be grateful for any pointers that could help narrow down which specific USB interface chip would be most suited for this application. In summary, the signal imputs from my DIY flight sim throttle quadrant will consist of FOUR analog potentiometer settings - one each from the speed brake and flaps lever, and a pair from the throttle levers, along with TWO on-off switches connected to the thrust reverser levers.

For the flaps lever I intend to created fixed detents in the quadrant housing, along the flap lever's axis of travel, such that specific potentiometer settings of that lever will correspond to incremental flap settings that I can assign for the various heavy metal jets that I intend to fly. As an aside, my all-time favourite flight sim jet is the Level D 767-300, and it is on the throttle quadrant of that bird that my DIY unit will be modelled.

Any advice at all would be greatly appreciated. Thanks in advance. Tony

 

[cowana]

The easiest way to do this is to buy a cheap USB joystick, and use the PCB out of that - it already has all the USB parts configured.

 

[grasshopper]

That is a good idea, Cowana, but with four separate potentiometer inputs to the USB link, namely the two throttles, the flaps and the speed brakes, as well as the dual on/off thrust reversers, I'm not sure there will be enough available data channels on a joystick to handle this throttle quadrant. I will look into this idea a bit closer though. I'd rather go the least complicated route to a solution whenever possible, and the joystick will definitely work with the helicopter collective lever that I also intend to fabricate.

Much obliged for this tip, and any others would also be appreciated.
Tony

 

[misterT]

Maybe something like this: U3 | LabJack
I don't know how easily you can use it in your simulator software, but there are many others similar products (USB DAQ) in the market. Some of them are HID compliant.

One option is to buy two or more cheap joysticks and build from them.

EDIT:
I also found this, might be perfect for you: PoKeys55T USB Keyboard/Joystick Simulator
It has 5 analog inputs and can be used as a custom joystick.
Manufacturer: **broken link removed**

 

[grasshopper]

Wow ! That is cool, Mr. T. Five analog inputs will work very well for this project. I'm looking up these links now. Much thanks.

 

[grasshopper]

After a good deal of searching the net, I finally found the ciruit that will work for my throttle quadrant, and it turned out to be a very simple design built around a $3 chip. The costliest components in the design are likely to be the six rotary potentiometers that will be connected to each lever of my DIY flight sim throttle quadrant. My research confirmed also that 100K ohm rotary pots with a linear taper, and 90-degree rotation, are the best suited for this function, but finding one that fits that precise description has been a job, to say the least.

If there is anyone here who is aware of a vendor that markets 100K ohm linear rotary potentiometers, adjustable over a quarter turn ( 90 degree rotation) from zero resistance to full deflection, I would be grateful for a link for any vendor where such a potentiometer can be ordered. Thanks again for any pointers that can be offered.