Well, my new Black Horse Chipmonk ARF has those strange devices called flaps. This is something new for this WWI boy. So how do you set the things up?

I'm using an Airtronics RDS8000 2.4g and the manual isn't at all helpful. It tells me to use Ch6 for flaps and I can indeed get the three position switch to move one of the flap servo arms to three positions. But that's as far as I can get. I tried connecting the other flap servo (2 aileron servos and 2 flap servos) using the usual Y-harness but that moves the the servos in opposite directions (as with the ailerons). Do I need some different type of harness? Or is there some setting on the radio?

Then there is the matter of "tradition." Traditionally, which setting on the 3-position switch is zero flap? Do people prefer "away" as zero and "towards" as full flap? Also how do people normally adjust flap settings? I would assume that one would set the zero position. But the manual seems to suggest setting the mid-range setting (50% flaps) first and then using the CPA and EPA to set zero and full flap positions.

Next thing you know, I'll be doing stuff like this!

http://www.youtube.com/watch?v=Q0YeqEOFS1Q

*****

But not with MY radio. []

I won the same Airtronics radio you have at a contest last Fall and have installed it in a Val dive bomber. The flap setup is a bad deal with this radio. On my JR radios I can use two channels for flaps with one the master and the other as slave. The slave is set to run opposite to the master and the flaps deploy normally. This cannot be doone on the RDS 8000 because, as you have learned, the normal flap channel does not allow you to define a slave channel. If you pick another channel to be the flap master, then you are limited to two-position flaps. So I reworked my initial installation of the flap servos so they are installed in the same orientation, rather than mirror images as usually done. Then they work OK off a "Y" harness. A reversing Y ought to work with mirror image servos, but I have never used one.

I then followed the manual for setting the center and endpoints, and took what I got for "half flaps". My JR radios are set up with a knob for proportional control of the flaps on those models.

I use forward switch (towards the top of the transmitter) for flaps up. Others' brains probably work with different logics and use the reverse.

That's a bit of a bummer, but since mostly I do WWI stuff this hasn't been a problem. Anyway, thanks for the tips and tricks. The "same orientation" trick works fine and all I needed to do was turn the servo hatch around, flip the servo over, and realign the control horn. On an ARF, this is no problem, but would be a serious annoyance on a serious scale model.

I think for me (and my left-handed brain) pushing the switch DOWN for DOWN flaps seems the most intuitive. In one of the MAN publications there's an article by Roy Clough (Jr.) titled "The Merry Modeler's Mindset" and it's all about how setting up switches and such on a model in a consistent "mental orientation" can save the your model. For example, switches are "on" if upward or forward.

Nice Val, BTW. [sm=thumbs_up.gif]

I'd need something like this to solve the problem electronically.

http://electrodynam.com/store/YHarness.html

Next question: Since the instruction manual for my Black Horse Chipmonk 60 ARF doesn't give any recommended throws for the flaps, what's a good (and "conservative") "full" setting?

I still don't quite get how to use the CTR and EPA to set the positions. I would assume I just set ZERO (using push-rod adjustments and I guess also CTR) on the "no flaps" position on the switch and then set a "full flaps" on the 3rd position using the EPA. The 2nd position would just fall where it falls (presumably somewhere around 50% flap).

BTW, I do know enough about flaps to know NOT to use them at all until I'm used to how the model flies. And that it's a bad thing to deploy full flaps at full speed.

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OK. I THINK I GOT IT. Everything seems to be functioning now (just needs fine tuning).

About 45 degrees

Thanks. 45 degrees seems like a lot when you think of aileron deflection.

Next question, when would you deploy full flap vs. half flap? Do you switch to half flaps on the setup leg and then full on final?

Generally I use half flap (or a smaller percentage of flap) for take off and climb out. On my jet half flap gives a comfortable amount of 'up trim' so to speak & this equates to a nice climb rate without elevator input.

On landing I slow the model, drop the wheels then full flap on the downwind leg on a rectangular approach. Then it's back up on the throttle to drag the model to the strip using the throttle to control the rate of decent & the elevator to control the pitch angle.

It's a bit of a different technique to rag & bone aeroplanes but that's what you do with heavier, flapped aircraft.

Not unusual at all, many use more, a Spitfire uses 90 deg.

Pitch change on models is usual with flaps, either up or down, this can be mixed out with elevator mixing but the pitch change will probably vary with speed so it's hard to get a setting to suit all speeds. - John.

Actually, I don't expect the Chipmonk ARF to be much of a handful and flaps are probably "optional" on this sort of model. But it'll be nice to learn something new.

Doesn't that amount to an airbrake?

I have found that if you wait until you make your turn on final and start adding flaps with the nose down, it is not as likely to pitch up. When deploying flaps on the down wind leg the plane is still flying too fast and will tend to pitch up. That is not really a terrible thing to happen but it just isn't very pretty. This is for the more conventional type prop driven planes.

The spitfire has a small split flap so it is not real effective until all down and I think the real plane or at least the early ones only had down and up, nothing in between. Flaps are fun to play with on a small model because they are not really needed; on a big heavy fast plane they become necessary. On a windy day use less flap to get through the wind.

Check these articles up:

http://modelairplanenews.com/Media/M...ager/flaps.pdf

http://www.auf.asn.au/groundschool/umodule4.html

http://en.wikipedia.org/wiki/Flap_(aircraft)