GAD 27 Flap Wiring...Help?

[Laird]

So I'm doing my schematics for my G3X and I'm trying to understand the attached diagram of the GAD 27/Flap wiring.

In my old RV 6, I had a momentary ((ON) OFF (ON)) switch for the flaps. You would just hold the switch in the direction you wanted the flaps to go and when actuator reached the limit, it just spun until you released the switch. Simple enough, or if you wanted 1/2 flap you just let go the switch right about "there", although I almost never used anything but full. Maybe the RV 8 needs 1/2 flaps for the "tail low" wheel landings I've heard so much about?

Anyway, looking at the G3X GAD 27 diagram it seems like they want me to use a 3 position switch ( ON,ON,ON). OK, but if you want a mid position, you kinda have to be careful about switch placement when moving it. OK, so be it.

I'm planning on using the stock flap motor that was supplied with my 2018 kit. I know there is a new style, larger motor with internal feedback positioning, but I already have the stock flap motor mounted and a nice cover for it, and a MAC position indicator for the GEA 24.....and I'm cheap.

Two questions I have are:
1. The diagram shows limit switches at the up and down position. I guess that it's necessary or the GAD 27 will keep running the flap motor if it doesn't get a "home" position. My guess is it probably will.

2. Even using the MAC position sensor wired to GEA 24, how does the GAD 27 know where the "1/2 Flap" position is? I don't see any communication between the GAD 27 and the GEA 24 to tell it where it is.
What I'm I missing?

Is it all just for the convenience of touching the switch once and forgetting about it? Just me but I'm not sure it's worth all that.

I'm considering not wiring the flaps to the GAD 27 and going my old RV 6 "simple" method that worked for 2000 hrs. Seems simpler. I really like looking out the window to verify the flap position and don't need to see it on the screen.....probably take me longer to find it on the screen rather than just looking anyway.

Can someone shed light why the GAD seems so much more complicated (to me)?

Thanks for the help,

Laird
SoCal

 

[Bavafa]

I don't know about this diagram but I have momentary ON-OFF-ON switch connected to GAD 27 and it work as such that when I push the up or down, the flap goes to my next preset position. I have 4 preset position and from a fully down if I push up four times up, it will fully retract and I don't have to wait till it gets to the next preset position before I push up. The preset position will require a potentiometer and with that you will not need a limit up or down switch.

 

[Raiz]

Two questions I have are:
1. The diagram shows limit switches at the up and down position. I guess that it's necessary or the GAD 27 will keep running the flap motor if it doesn't get a "home" position. My guess is it probably will.

2. Even using the MAC position sensor wired to GEA 24, how does the GAD 27 know where the "1/2 Flap" position is? I don't see any communication between the GAD 27 and the GEA 24 to tell it where it is.
What I'm I missing?

I think you are mixing two different configuration options for the GAD 27 flap control. The first option (which is what your diagram shows) uses a multi-position switch (e.g. ON-ON-ON) where each position corresponds to a specific flap position, so when the switch is in the mid position, the flaps will be in the mid position (and up for retracted, down for fully extended). This is often found in Cirrus aircraft and some Cessnas that I've flown. The other option is what you've described but it uses a momentary (ON)-OFF-(ON) switch. Pushing the switch momentarily to the up position will cause the flaps to move upwards to the next pre-programed position. So, in answer to your questions:
A1. The GAD 27 will stop the motor at the pre-programed position based using the MAC position sensor connected to your GEA 24.
A2. The mid position (and all positions) are programed as part of the setup process. The GAD 27 gets the position information from the GEA 24 via the CAN bus.
For further info, check out sections 3.1 and 30.4.14 of the installation manual.

 

[Freemasm]

I'm NOT the guy but for the type of control you want (relative), would appear you simply wire the up/down (mom)s to pins 18 and 19.

 

[Scott Chastain]

Hi, Laird,
I know you claim to be "cheap," but Pat's flap motor is far superior to the old Van's actuator. It is a definite worthwhile investment and really not all that expensive. Anyway, here's what I did. Like you, I kept things simple.