PFC Yoke Jumping Wildly On Z Axis

[westes]

I finally have Peter's PFC drivers more or less working with a PFC Cirrus II Console. The most serious remaining problem is that when I am pulling up on the yoke or releasing it, the sensitivity is ridiculously too high. On an approach in a King Air to Telluride a very slight tug on the PFC yoke gave an altitude gain of 1000 feet and gently releasing this would bounce between descents of 100 and 2000 feet. It was very very difficult to control and did not behave as you would expect a yoke to behave. I saw a substantial improvement when I checked the "Filter" checkbox, but sensitivity was still set way too high.

With a USB-based device, I could adjust sensitivity in FS2004 directly. Since this is a serial console, I don't see a way to control sensitivity in either FS2004 or in the PFC drivers. Is there a trick to adjusting this?

[Pete Dowson]

I saw a substantial improvement when I checked the "Filter" checkbox, but sensitivity was still set way too high.

If you have the response set to linear, then the sensitivity is exactly as it needs to be to reach to maximum deflection at either end. If you want less sensitivity near the centre you need to select one of the "S" shaped response curves. This will make it even more sensitive at the extremes to compensate for a flatter response near the centre. It is still necessary to be able to reach the extremes -- if they are "too extreme" then it is the aircraft model which is the problem. You can adjust control surface efficiency in the Aircraft CFG files.

With a USB-based device, I could adjust sensitivity in FS2004 directly.

Yes, but FS's sensitivity slider is just a divider -- it reduces both the range of movement you can achieve and the resolution of the control input. Even with such a device I would say that you could get much better results setting sensitivity to maximum and calibrating in FSUIPC with an S-shaped slope applied.

BTW nothing in what you say seems to relate to your subject heading "jumping wildly". Where does that come from? If the response is jittery up and down, and fluctuating wrongly, then you either have a faulty connection or a bad pot, or possibly or poor power supply. You probably should talk to PFC.

Please also try the interim release version of PFC.DLL (1.998) available in this Forum (see top), as it does fix an error in the X axis which may cause jitter in certain circumstance.

Regards,

Pete

[westes]

Let's put some numbers behind my statements to help clarify things. Words like "jumping" and "fluctating" or "jittery" don't get at things precisely.

I measure from the faceplate of the Cirrus console up the silver metal column to the start of the back of the Mooney style yoke at 2 1/4 inches. A pull of the yoke to its full extension gives a measurement of 3 3/4 inches. So the maximum I can deflect it in that direction is a mere 1 1/2 inches. On a typical descent, I am pulling the yoke maybe 1/4 of one inch. So if one wants to speak about things in linear terms, I am using about 1/6 th of the total possible movement of the yoke.

That relatively minor 1/4 inch deflection will in some cases give me 1000 feet / minute of climb (during a descent that I want to stabilize at around (-700) feet / minute). In other cases the 1/4 inch deflection gives a 500 feet / minute climb.

So, first, there is no consistency in the result I get, which makes it very very hard to stabilize my approaches, and second the absolute response to very small deflections seems in some cases absurdly too high.

I will try 1.998, but could you point me to where I set these things:

1) Linear response

2) S curves

[Pete Dowson]

I will try 1.998, but could you point me to where I set these things:

1) Linear response

2) S curves

That's both one -- a linear response, which is the default, is a "straight S curve".

Didn't you get any documentation with the PDF.DLL? If not then it wasn't my ZIP you received (the current user release is over at http://www.schiratti.com/dowson along with all my other FS software. You might need to download that first in order to get the documentation you appear to have missed).

It sounds like you've not even calibrated the controls yet -- that should be your first step. The instructions are all in the document. There's even pictures, including one of the "S curve" facility, which is actually entitled Sensitivity changes: "Response Curves".

I know most folks don't bother to read instructions until all else fails, but it really would work out quicker than extended exchanges on a Support Forum. ;-)

Don't forget to check the aircraft model you are using too.

Regards,

Pete