Pots 101

[ak49er]

I have bought both 10k and 100k pots to use for my yoke and elevator axis. They are both linear. I have wired them up to an old wheel and gears from the old wheel,and have had limited results using FS to configure the axis. I canget either to acuate only the left aileron or only the righ,( if i reverse the axis.)First are these the correct type of pots for this app. ?Second, am i missing the boat by not using FSUIPC for axis assignment, I read that with FSUIPC, one can define his own center point. Third, when I dissassembeled the control wheel, i saw only two wires leading to the pot, and only two were soldered in, yet there are three recept5acles. This is the case with my new pots as well they have three receptacles, do i use two or three wires? Which pot to use where? 10k, 100k, sliding, etc.

[ve4anc]

Hello AK:

You will use the center terminal and one (either) of the outer terminals. I say either outer terminal because you have the ability to reverse the settings in the regular windows software. With the shaft of the pot pointing toward you, I use the left terminal and the center so resistance value increases with a clockwise rotation of the shaft.

Jumping to a conclusion, with respect to your calibration problem it sounds like you might have connected onto the two outer terminals for your test, and you got full deflection with no effect from moving the pot knob...if I'm reading this right. You'll get no effect because the two outer terminals are giving a fixed value of the full resistance of the 10K or 100K pot, not going through the internal wiper connection which changes the resistance. This provides a full deflection of the aileron to the interface input and doesn't change, hence your ability to see only one aileron in the display.

For "proper" resistance value, I've only used 100K pots for my nmajor controls, so I can't advise you further except to say I wired a 10 turn pot of 25K into my interface for the elevator trim axis and it worked for me although I found the trim in FS 2004 to be pretty touchy. I switched it out for a 100K pot, but the trim sensitivity didn't seem to change much with the greater value.

Hope this helps out AK. Best of luck with you project, fooling around with this stuff is really neat once you get past a few initial hurdles.

Regards,
Lee Smith

[spitfire9]

Lee,, Try using a rotary encoder for trim.

I haven't tried it myself but you might get it to work that way using the Plasma software to set less pulses and dampen the touchy trim in Fs2004 ??

Brian

[Mike.Powell]

AK49er,

What are you connecting the pots to? Without knowing, it's hard to offer specific advice.

A two-wire connection from the pot was typical of older game controllers that plugged into a gameport. Most USB game controllers use a three-wire connection to the pot. Using a two-wire connection on a USB game controller generally won't work.

Mike

[ak49er]

Thank-you all for your advice, yes Mike, I am connecting to an older game port device (game wheel), which I plug into my Computer with a USB adaptor> So now since it is a gameport device, connected via usb, do I use two or three wires.

[Bob Reed]

Hmmmm I never had any luck with those converters. Did the wheel work that way before you modified it?

[Mike.Powell]

ak49er,

If it is specificially a gameport device to USB adapter like the Rockfire 203 (I think that's the model #), then two wires from the pot, wired exactly as though it would plug into a gameport, should be correct. If it's a USB adapter like one of the Beta Innovations products, you'll need three wires.

You should be able to open your computer control panel, select "Printers and other hardware", then "Game Controllers" and see your adapter. Select the adapter from the list and click on "Properties". You should get a window with two tabs. Click on the "Test" tab. This gives you an easy way to see how the adapter and pot are working together.

Mike
www.mikesflightdeck.com (http://www.mikesflightdeck.com)

[imported_767300]

Hey guys whats the difference between a 10k and a 100k pot?

[Mike.Powell]

Hey guys whats the difference between a 10k and a 100k pot?


The "k" is an abreviation for 1,000 ohms. So, a 10k pot has a 10,000 ohm resistance element while a 100k pot has a 100,000 ohm resistance element.

Mike
www.mikesflightdeck.com (http://www.mikesflightdeck.com)

[pdpo]

Hi there,

as you are using a older type of gameport you need to use 100k (100,000 ohms)
potentiometer and use one outer and the middle connection. This is due to the way how an older gameport works. It will set a voltage over a series of a condensator and the potentiometer. The higher the resistance, the longer it takes for the voltage to rise until a certain level. This time it takes is then used
to determine the location of the slider.

Most of the newer systems require 3 wires and will present a reference voltage
over the total resistor and measure the voltage over the slider. The ratio of those two will determine the location of the slider.
For this reason the 3 wires.

Voila, some background....

Greetz Peter

[ak49er]

Thank-you all for your well phrased responses, I had no idea there could be so many variables in pot, ports, and interfaces, I never would have concluded the points that have been explained. When I return home I will better prepared.