Building a throttle quadrant/joystick

[109dreamer]

I was wondering how difficult it is to build your own throttle quadrant...I know little about electronics however I do know how to solder and wire light fixtures(big deal I know).
ANyway I found a tutorial on how to do this and I went ahead and disassembled an old non working joystick I have...I found two pots in it and was wondering if all it is, is simply connecting a pot to a usb cable, plugging it in, and I have my very own throttle....or is it alot more complex than that?

thanks

109

[P-40_Warhawk]

It depends. Look at the how-to section of flightsim.com. Some people just hook the pots up to USB and some use gears, or pistons.

[109dreamer]

geez P40, I found out how to do everything but build a rocket and fly it to the moon!  Great site thanks a million

109

[JBaymore]

It depends. Look at the how-to section of flightsim.com. Some people just hook the pots up to USB and some use gears, or pistons.

Unfortunately you can't hook pots DIRECTLY up to USB... you need an interface circuit in there.  But hooking up to gameports is easier and that CAN take straight pots.

Usually the "deal" with using an old joystick is to use the joystick's existing usb interface and hook the pots up via a new mechanical linkage to a homebuilt throttle quadrant.  Then you assign the functions in the joysticks section of the setup part of the sim.

However... if you are running multiple throttles... you have a little problem possibly sneaking in there.  At any given physical setting of the two or more throttle levers... the resistance of the pots may not match exactly.  That will translate to eneven thrust.  So you'll have to individually "tune" the levers when you are slying.

Real controls for throttle quadrants have some "smarts" built in that make the individual throttles assume the same setting if thay are set within a certain range of each other.  It kind of "averages" the 2, 3, or 4 resistance values being produced.

There is more info here on this kind of stuff too.

best,

....................john

[109dreamer]

Thanks John, now I understand why so many homebuilt throttles are using ports and THEN plugging them into a USB cable....I am going to go play around and see what happens..if I do not come back to this forum, it means I blew myself up

109

[chuckcrc]

Hi 109
the easiest way to contruct the electronics for a throttle quadrant (I assume single enging here) is to buy a cheap USB type joystick and strip it down. If you look at the thread I have on this forum for Throttle quadrant I originally used a cheap (Aud $30) Thrustmaster USB joystick which I stripped down for the unit. This also gave me 4 buttons and a HAT switch. It was easy then to plug into the PC and CFS2 will allow up to 16 joysticks which can be assigned different commands in the Game control menu setup.

If you want more than this then you would need to look at buying a dedicated type of electronics.
I bought a Betainnovations Plasma USB Controller which gives me 16 axis, rotary encoder inputs , 64 button inputs and an add-on module unit that you can hook up four Hall Effect pots which will eliminate the effect of asymetrical thrust problems when using multiple throttle levers.

Would it help if I disassemble my Throttle quadrant so I can get some pics of the wiring inside for you.

John Baymore is there a way we can post some form of tutorial on this forum to get this info available to everyone.

cheers
chuckcrc

[P-40_Warhawk]

You said multiple pots may be diffrent. What if there brand new and from the same company?

[oldhorse]

Hi 109
 I found this tutorial to be a good starting place

http://library.avsim.net/esearch.php?DL ... CatID=root

[JBaymore]

You said multiple pots may be diffrent. What if there brand new and from the same company?

Potentiometers come in various "grades" ....... which in addition to other thngs relates to how "accurate" the resistance values are for a given physical setting.  

So on say a linear that has 2" of total "travel" and is set to being at 1" (centered) .... if you tested 100 pieces set the same way........ the resistance values would be slightly different.  Basically there is a linear and direct relationship between the closeness of this figure.... and the COST of the pot  ;).

Unless you buy VERY expensive ones... the tollerance of this kind of value is more than you likely will be able to accept for multiple throttles.

Check the Beta Inmnnovations site for a really nice option for a LOT of cockpit interfacing stuff.  

Also... exciting news here...... GoFlight is coming out with a new interface unit for simpit builders that will combine the functions of a number of it's existing boards into one unit without the switches/displays.  So you can remote the stuff onto your homebuilt panels.

best,

...................john