Snap Flap use

[Wing-span]

Anybody using snap flap in TD or F3J flying? When do you use it and in which flight modes do you have it active? Indeed do you feel it is of benefit or even needed?

I tried to set it up on my PCM9XII (9303) but the flaps drooped over the full motion of the elevator stick and not the last few percent :confused: . I followed the instruction manual. Has anybody else found this using the instructional techniques or is there another way? I would like to set it up on a duplicate model 'memory', just to try it out at least. Flying an Xperience Pro V.

[OVSS Boss]

I have just done it for a B ship, will get the radio in here and go through it for you.

Marc

[OVSS Boss]

Ok, here we go.

Go to ELE-FLP Screen, This screen will set just the flaps to whatever elevator movement you want, I have set up two set ups here. One for thermaling, one for speed runs. Position 0 is for my speed set up, and that is the real snap flap for me. On my radio, Position 0 has the detent down under SPD, all the rest are up for Position 1, and that is for thermaling. In the line that has POS 1 or 0, you can insert your values you want to give the flaps to go for either up or down, in mine POS 1 have +11 in the up value and POS 0 has =25. Now, move to the right, you have the Offset value, and that is what gives you snap flap. In my POS 1, I have 0, in POS 0, I have -50, and that gives me the throw starting at 50% of the up elevator throw. What we just did is what sets the flap throw. So as it is now, I have across the board E-F mix in thermal mode and I have E-F mix starting at 50% of the ELE throw in speed.

Now go to the FLAPRN Mix screen. This is where you get the ailerons to go with the flaps to give you full span snap flap. Here, just go to in my case, SPEE and I have +50, and in THRM I have a value of +70 to get even motion of the TE over the entire span. There is nothing else noted on this screen for me. On my test flights yesterday, it all seemed to work just fine.

Any questions, just bring'em here.

Marc

[aeajr]

I have it set up on my Legend and Thermal Dancer 3M full house planes. I turn it on when I am thermaling for more and more uniform lift when I pull elevator. Very small amount of flap.

[Andy W]

Nice thing on the EVO, you can put these mix percent settings onto one of two digi-adjuster dials, and unlock and modify the mix amount in-flight. Then you can easily see modify the settings to get the handling you're looking for..
..a

[OVSS Boss]

The Evo is a great radio, but in the case of SF, I am using it in speed runs only, so there is really no time to do anything and really the only change I might make is the offset value, when the flap change begins. I have learned how much i need, just the sweet spot to start it. In thermaling regimes, it is on all the time if I use it (which is not very much).

Marc

[Robglover]

I have snap flaps that automatically enabled in speed mode. They can be cut off altogether with another switch. Some days they seem to work great for light thermal conditions, other days they just seem to make the plane a slug. I am currently flying a Futaba MZ14, makes setting this type of stuff up easy. The snap flaps were working well today.

Rob

[Andy W]

I meant it makes it easy to tune the mix until you find that sweet spot, didn't mean to imply you'd adjust it all the time.

Are you saying you do or don't use it while thermalling? Sounds like another topic for detailed discussion like the X vs V debate..
..a

[OVSS Boss]

Right now I only have one ship that I use E-F mixing when I thermal, and that is a Fazer. I am a bit like Rob, my experience has been that this mix usually gets most ships to being a slug just when you need it not to be the worst. The Fazer for some reason just loves it though and a lot of it. The Fazer's airfoil, HQW 2/8, is fairly fast in cruise, so for normal search, I drop the TE about 1mm, and then when thermaling can add on a slider as much as 3mm. Then the mix can add an additional 3mm or so to it when I am really pulling hard. I know by convention, this sounds like really wild amounts, but on this ship it works. Now, on my Insanity's, no mix at all and I have between 1-3mm on each end of a slider.

Marc

[Chipwillis]

I had tried running snap flap on my Eraser, with the MH32 airfoil. My amounts were too much and I ended up hating it. Perhaps I could try again, but it would seem for max efficiency, to use fixed positions would be better.

So on the 9303- I just get used to using the R3PS and it is up for speed, middle normal cruise, and down for thermal. On my Shadow the current
TE movement is about 2mm up, neutral, and 2mm down. I am still fine tuning this to my liking but the simplicity is each flight mode has its own trim setting.

Snap flaps on the other hand surely causes some trim change and I just never could get the turns to be smooth and ended up overcontrolling too much. I don't like much Expo in my sailplanes, but maybe that would help.

I do have camber adjust on the left slider that overrides the other modes, and every now and then I will play with it, but for simplicity sake, I have been trying to just use fixed positions.

Marc, for B flying the idea is to use snap flap for the Speed Event right, for quick turns?

[Wing-span]

Can anybody explain the advantages of using Snap Flap in 'thermalling mode'. I think the advantages are obvious on the slope (F3F) and in F3B speed run turns, but why is it useful at slower thermalling settings?

[OVSS Boss]

Correct Chip, it can give a wickedly crisp pull from a knife edge position.

Marc

[Robglover]

Snap flap for thermals can be a mixed bag.

As Chip noted, it doesn't work too well for the MH32. I always found that my lightly loaded MH32 equipped planes thermaled best with the trailing edge at neutral with a bit of speed. No camber needed for that airfoil, and if I added some it suffered.

Other airfoils are different. With some of them I find snap flap to be very useful for small light thermals. Others work well with small hot thermals. It can work well for surfing waves. Sometimes it works well one flight and lousy the next. Put it on a switch so you can turn it off and on in flight and figure it out.

Rob