Elevator Trim problem

[John Fee]

Pete

I'm using FSUIPC 3.999w 12 Aug 2012 and FS2004.

For longer than I care to remember I've been using FSUIPC button assignments to control elevator trim via a rocker switch on a CH Eclipse yoke. This worked very nicely until recently after I deliberately deleted FSUIPC ini.

I've got everything back the way it was except for elevator trim up/down. Under Buttons and Switches, I assign 'Home' key for trim down, and 'End' key for trim up, but this produces erratic responses to the rocker switch. I have tried this with 'key press to be repeated when held', and not; and I have tried it with 'profile specific' checked, and not.

I ended up re-enabling FS9 joystick and reverted to FS control. The upside is that I can now use the FS 'Hat' control.

EDIT: This failed after a re-start and I was back to square one. I was getting full trim up or trim down no matter what I did.

Is there something about elevator trims (they are axes after all) which makes them tricky to set up using FSUIPC keypress assignments? Or have I, as is often the case, missed something obvious?

Thanks as always for your continuing development of FSUIPC. I've been following the FSX friction discussions with interest.

John

[Pete Dowson]

Under Buttons and Switches, I assign 'Home' key for trim down, and 'End' key for trim up, but this produces erratic responses to the rocker switch.

Why assign buttone to keyboard presses when there are perfectly good Trim Controls to assign to -- Elev trim dn and Elev trim up? All you are doing is sending keypresses to the keyboard buffer for FS to read and convert to the very controls you should use in the first place. It is never necessary or desirable to use keypresses for buttons and switches when there are the controls assignable directly. The keypress assignments part is intended for use with add-ons which don't process controls and have only key assignments instead.

Is there something about elevator trims (they are axes after all) which makes them tricky to set up using FSUIPC keypress assignments? Or have I, as is often the case, missed something obvious?

I think you've just missed the obvious, the assignment of buttons and switches to controls in order to control FS.

There's also an example (boxed, headed Offset Increment/Decrement Controls) in the FSUIPC user guide specifically aimed as showing how to use the offset controls to assign trim inc/dec controls with precisely the amount of control you want, rather than having to accept the standard FS inc/dec amounts.

Whilst elevator trim can be controlled via an axis (and many folks do), this path has to be taken very carefully, because FS uses the elevator trim for the Autopilot altitude modes, and unwanted inputs (jitter) from the axis can mess that up (though FSUIPC does have an option to disconnect the trim axis). Additionally, unless your elevator trim axis is motor driven (as in a real airliner, for example), when the A/P is diengaged it is likely that your axis trim will be in a completely different position to the current FS trim, causing stability problems as soon as you touch it.

For these reasons it is often wiser, and certainly easier, to use the trim up/dn controls or the offset equivalents instead.

Regards

Pete

[John Fee]

Thanks, Pete,

This was exactly the information I needed. I hadn't tried offsets before - scared off by the terminology. I now have the most balanced trim function I've ever had in half a lifetime of using FSUIPC.

I traced the original problem though. In the photo Button 24 points up at the green LED. This button is permanently active and in some way had become set to keypress 'Home'. This resulted in continuous trim inputs. I removed the key/button assignment - I hope permanently. I would like to disable this button but am not sure how.

Just one thing, Pete, I've not set these trim offsets to be 'profile specific'. Does that mean that these settings are active for any plane unless over-ridden by a 'profile specific' setting? I wasnt' sure exactly what the User Guide meant.

John

PS I set up the same trim offsets in FSX :)

[Pete Dowson]

Just one thing, Pete, I've not set these trim offsets to be 'profile specific'. Does that mean that these settings are active for any plane unless over-ridden by a 'profile specific' setting? I wasnt' sure exactly what the User Guide meant.

Non-specific assignments to buttons can be overridden by profile-specific assignments, yes. Otherwise they are additive. Same for keypresses. It is only axis assignments which are completely either generic or specific -- they have to be because otherwise axes you don't use in a specific aircraft could interfere with things (axes are alwatys active, unlike buttons and keys which need user action -- i.e. pressing/releasing).

Regards.

Pete

[Jetman]

This was the last thing for me to sort out for my flight controls, but the example on pg32 of the latest guide made it real easy :)

FSUIPC - what a great add-on !!