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Rudder Trim Knob

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Member
Registered: Jun 2015
Posts: 103
Location: Tucson, AZ USA
I have been looking into alternatives to the keyboard for the rudder trim. Does anyone have any imput on what has worked well?

I'm considering modifying an Extreme3D Pro joystick and using the twist function for the rudder trim, mounting the base of the unit under my center pedestal and mounting a self-made trim knob on top.

The other option -- and I don't know if this would work -- is to tap into the two unused fuel control switches on my 777 TQ and run wiring back to a self-made trim knob switch on my center pedestal. Am I correct in assuming that the fuel control switches are just on-off switches that could be configured to operate the PSX rudder trim?

Can anyone comment on how the rudder trim would work using a touchscreen for the center pedestal?

Thanks,

Jon D.
« Last edit by emerydc8 on Sat, 25 Jul 2015 22:57:17 +0000. »
Moderator
Registered: May 2009
Posts: 5140
Using a USB axis for rudder trim has 3 disadvantages:

- It will be unstable (especially when using the twist axis)

- It will not work if another axis is already assigned to the rudder pedals

- It will disagree with the 744 systems.


The only option is to assign two USB buttons to the rudder trim.



Regards,

|-|ardy
Member
Registered: Jun 2015
Posts: 103
Location: Tucson, AZ USA
Thanks, Hardy. I don't really understand the electrical circuitry of a USB switch, but do you think it would be possible to tap into the unused fuel control switches of my 777 TQ and use those for rudder trim?

For instance, could I tap into one wire going to each fuel control switch and add another switch -- in series -- that I could use for left or right rudder trim? (leaving the fuel control switches on continuously).

Jon D.
Moderator
Registered: May 2009
Posts: 5140
Every USB button assigned in PSX should be a momentary action switch; i.e. it should self-release to the unpushed position when you remove your finger.

Using an alternate action switch instead, e.g. a fuel control switch, doesn't seem very ergonomic to me.
« Last edit by Hardy Heinlin on Sat, 25 Jul 2015 10:20:35 +0000. »
Member
Registered: Jun 2015
Posts: 103
Location: Tucson, AZ USA
Thanks. I wasn't proposing to use the fuel control switches as rudder trim switches -- just the wiring going to the fuel control switches would be interrupted by the placement of a momentary-action rudder trim switch that I would make and install (in series) on the center pedestal.
« Last edit by emerydc8 on Sat, 25 Jul 2015 22:57:53 +0000. »
Moderator
Registered: May 2009
Posts: 5140
Well, when you move that switch and you see the word "pushed" displayed and removed on the USB page for that "USB part", then it will work obviously, and thus you will be able to replace the switch by a pushbutton. A wire is a wire :-)
Member
Registered: Jun 2015
Posts: 103
Location: Tucson, AZ USA
That's what I thought. I just wasn't sure if there was something more with the USB. Thanks.
Member
Registered: Jun 2015
Posts: 103
Location: Tucson, AZ USA
Just a follow-up to this, does anyone know of a manufacturer that makes a three-way switch that could be used for rudder trim on the PSX -- Something that when neutral is off, but will make contact to one terminal when turned counter-clockwise (left rudder trim) and a second terminal when turned clockwise (right rudder trim)?

Thanks,

Jon D.
Member
Registered: Dec 2009
Posts: 334
Location: KTPA
Jon-

Not sure about rotary, but any two way toggle will work just fine. Have you had a look at Leo Bodnar's stuff- brilliant. I rewired my entire PFC Console II with a couple of his cards, and now they are basic USB (used to be proprietary serial). Very easy to work with, and his support is second to none.

No affiliation- just a pleased customer-
http://www.leobodnar.com/shop/

HTH- C
Member
Registered: Jun 2015
Posts: 103
Location: Tucson, AZ USA
Thanks for the link and info on the boards. I may eventually get to that on some bigger projects. The big electronics store here in town didn't have any single-pole, double-throw toggles that were spring-loaded to the center, so I had to settle on a rocker switch for now until I find something better.

Just hooked it up and mounted it in the center pedestal. https://drive.google.com/file/d/0B-WRh0Hf7VdZUHN3XzM4akdhRnc/view?usp=sharing

It works great for engine-out approaches. I know some guys take the rudder trim out at 1000', but I never got used to struggling with the rudder pedals all the way down final, especially in the real sim where it seems that one centimeter of rudder could be the difference between being in a position to land when you break out at 100' or having to go around.

It was alway easier for me to get into a groove where I move the throttles slightly and then go back to the rudder trim every time -- back and forth -- just like they are connected (aerodynamically they are).

Ideally, it would be best to do like Britjet showed in his recent tutorial video, but a lot of times it's hard to time the flaps and gear so that you don't have to touch the throttles at all (at least I was never that good).

Being in trim where you can just about let go of the controls and have it stay where you want on a three-engine approach is definitely the way to go.
Moderator
Registered: May 2009
Posts: 5140
I would recommend to use two pushbuttons instead of a single 2-way-switch. The 2-way-switch can activate the slow trim speed only.

With two pushbuttons, if you push just "left" or just "right", you will get the slow trim speed. If you then additionally push the respective opposite switch, i.e. both left and right, you will get the fast trim speed.

I think Peter's timing trick refers to the fast trim speed.

Or add one pushbutton to the 2-way-switch; this pushbutton should then close the left and the right contact. When you hold this button additionally, you will get the fast trim speed.


Regards,

|-|ardy
Member
Registered: Jun 2015
Posts: 103
Location: Tucson, AZ USA
You must have read my mind. I was about to ask how to activate the fast trim!

So, if I just wanted to try the fast trim only, could I do that with the existing rocker? I think the switch springs back fast enough that a short blip would probably work. Do I jumper the left and right contact?

Thanks,

Jon D.
Moderator
Registered: May 2009
Posts: 5140
For the fast trim you need to close both contacts; the first closed contact determines the trim direction.
Member
Registered: Jun 2015
Posts: 103
Location: Tucson, AZ USA
Okay, that was kind of short-circuiting my brain trying to figure out how it knew which direction to go. So you have to press the direction switch first then short the left and right side?
Moderator
Registered: May 2009
Posts: 5140
Yep.


If you have bigger plans with your cockpit mockup, I would forget USB and go the direct way via TCP/IP. There are some companies now that provide hardware and interfaces for PSX via TCP/IP.
Member
Registered: Jun 2015
Posts: 103
Location: Tucson, AZ USA
Thanks, Hardy. Too bad I can't find a four-position rocker switch similar to the one I have now.

I'm not that familiar with computers to understand exactly what TCP/IP is in this context. Would it involve wireless switches that communicate via a network?
Moderator
Registered: May 2009
Posts: 5140
The Aerowinx network (main server and boost server) uses TCP/IP.

The network is used to synchronize multiple PSX instances with each other.

The network also allows add-ons to interact with PSX.

So, when I write "TCP/IP" in this context, I simply mean the Aerowinx network. All PSX add-ons and hardware interfaces use it.

For reference: https://en.wikipedia.org/wiki/Internet_protocol_suite
Member
Registered: Jun 2015
Posts: 103
Location: Tucson, AZ USA
Thanks. The only other item I am looking to add is the gear lever. I was using Interface IT Management Control System software to send a "g" keystroke to FSX when the gear handle was moved, but I don't know if this is recognized by PSX or how I would get around the fact that my 777 gear handle does not have the OFF position like the 747.

Can you tell me which companies make interfaces for PSX via TCP/IP?
« Last edit by emerydc8 on Tue, 28 Jul 2015 07:41:11 +0000. »
Moderator
Registered: May 2009
Posts: 5140
Quote
Can you tell me which companies make interfaces for PSX via TCP/IP?


Here's a list; please scroll down to "Hardware Add-ons":

http://aerowinx.com/html/addons.html
Member
Registered: Jun 2015
Posts: 103
Location: Tucson, AZ USA
Thanks, Hardy.

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