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Flap Handle Placement?

claycookiemonster

claycookiemonster

Well Known Member
I've just found out that the flap switch I put on the stick grip needs another standard flap handle to operate normally. Apparently the stick grip switch isn't capable of enough current to operate the flaps?
So, now I'm looking for a non-instrument panel location for the more normal flap switch. I've seen photos of some on the aft side of the gear tower, so forward of the throttle quadrant beneath the panel. There was one aft and below the throttle quadrant in the lightening hole at an angle. I've even considered one mounted vertically on the upper surface of the throttle quadrant forward of the levers if it could be done without interfering with the cables.

Suggestions? Warnings? Lessons learned?
 
Use a relay with the stick mounted switch. No high load to the switch that way. Airline pilots...if you ever passed through DFW and had a maintenance item, I probably met you.
 
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A reversing relay setup is needed if you want to use a low-current stick switch.

A typical location for a standard flap toggle is the bottom of the instrument panel above the quadrant.

I happen to have mine on the throttle, with a relay deck mounted elsewhere.
 

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The Van's FPS looks interesting, but don't I see a toggle switch among the kit items? Aren't I trying to avoid such a thing?
Also, with a Dynon HDX 1100 and a VPX-Pro, is it possible I already have the situation solved? I haven't read that manual yet.
 
fl-mike said:
A reversing relay setup is needed if you want to use a low-current stick switch.

A typical location for a standard flap toggle is the bottom of the instrument panel above the quadrant.

I happen to have mine on the throttle, with a relay deck mounted elsewhere.
Click to expand...

Never heard of a reversing relay. OP can either buy a "relay deck" from several different suppliers made for this purpose (caution as some are made for trim motors and may not be able to handle the current of the flap motor) or make there own by properly wiring two standard SPDT or DPDT (10A or larger) 12V relays. They cost about $3 each. Many sources for wiring diagrams - wire to each motor leg goes to center terminal, then + on one leg and - on the other. Then just wire in the controls so that one switch gives + or - and the other - or + to the motor.
 
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Clay,
Check the VP-X installation manual, page 40 concerning flap wiring.
I installed a momentary ON-OFF-ON switch just above the throttle quadrant as many do.
 

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The flap motor draws several amps and has to be able to run in both directions, so something a little fancier than a simple on/off switch is required.

The simplest way is to use a DPDT switch that is appropriately rated to handle the flap motor current. Power flows through the switch straight to the flap motor, and the reversing function is handled by how the switch is wired.

If you want to use a single-pole switch, and/or a tiny low-current switch such as you'd find in a stick grip, you need to add some other components to handle switching the motor current. This is commonly done with a pair of relays you can buy pre-made from various manufacturers, or build yourself. In this application the switch only has to carry a small amount of current that energizes the relays, so you can essentially use whatever switch you like.

The equivalent behavior can also be achieved with solid-state components; TCW sells a product that operates similarly to a box full of relays but has no electromechanical parts to wear out. Nowadays the same functionality is often built into various electrical-utility products: the Garmin GAD 27, the Vertical Power units, and I think AFS has something as well. If you have any of these, then you can use any switch you want, because the switch is is only providing a tiny signal to a computer which in turn handles the motor current chores for you.

The Showplanes FPS, which I have, is more like the first case than anything else... it has some smarts in it to stop the flap motor at a predetermined position, but it is wired in such a way that motor current passes through the switch, not just logic signals. So you do need a fairly beefy switch (but it can be a single-pole switch).
 
The Infinity Grip flap toggle switch easily handles the current draw using the SP Flap Positioning System.

Have this flying on all builds.

Carl
 
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