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Attention Magnum Owners!

11 posts in this topic

Posted

I am still having problems with my flight controls.  I need someone with a Magnum to verify how the flight controls work, specifically the flap handle.

I wrote down these numbers as the flapperon son went from zero flap handle input upto 15 degrees in 5 degree increments.

The over all result is a loss of left and right stick control as the flap handle is pulled up.  Is this correct?

here are the numbers

-2 degree flaperons (handle down) = 46.5 degrees of total flapperon movement L/R

+3 degree flaperons (handle @ 5) = 37 degrees of total flapperon movement L/R

+8 degree flapperon (handle @ 10) = 25.5 degrees of total flapperon movement L/R

+13 degree flapperon (handle @ 15) = 16 degrees of total flapperon movement L/R

See, it reduces Left and Right input to 16 degrees of travel!

 

Any help would be appreciated!

 

Thanks,

Ron

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Posted

Nothing like me answering my own posts.  This Magnum section is like my personal forum!  LOL!

I found this post made by Chris B talking about flapperon travel on the Fat Avid and Magnum...very helpful to understanding that the limits are the stick movement limits, not flight control elements binding.

"Hi Ed, I copied this from a long ago post for my Fat Avid. Is this what you are looking for???
So I got the controls all working perfectly. New cables, re mounting the flapperon horns and major adjustments did the trick. The control linkage now hard limits at the stick travel limit as it should to avoid stressing any other part of the control mechanism. I get approximately plus and minus 25 degrees of aileron travel stop to stop. I can pull in an additional 15 degrees of flaps, and still have the stick travel hard limited at the stick limits as it should. Full flaps and full aileron deflection provides almost exactly 40 degrees of total down travel. That was a major piece of work to get all figure out, but it is now functioning identical to my MKIV and Magnum.
Chris"

 

That makes sense to me now.  I'm headed to the hangar to fix it.  I'm determined to be victorious today!

Ron

 

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Posted

Ok, Barry Cole (New Magnum Kit Owner) helped me troubleshoot this.  We definitely got the controls a lot closer to right.  We found that the two torque tube fittings had welded arms that were pinching the heim bearings...I'll post pics.

My question now is, how far are the flapperons supposed to deflect?  From the above info the answer is 40 degrees, but my max deflection is 35 degrees before the nose of the flapperon nose hits the flapperon horn...this could be an issue at 15 degrees of flaps.

What do you guys think?

You can see the pinch marks at the base of the heim bearing

IMG_1930.thumb.JPG.c9ae2fab655095c54fe78

Pinched and binding flight controls

IMG_1929.thumb.JPG.86e32752254978e6e8d05

Notched out solved a lot of the problems...

IMG_1931.thumb.JPG.764c8c22efa9569e5fc50

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Posted

Is it possible to reverse the T shaped black tube in your picture?  Maybe there is more clearance on the other side and it's installed backwards????  Just guessing. :-)  JImChuk

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Posted

If they are hitting the hanger then thats about all your going to get out of them.  Mine are around 15° down at full.  I say you fly it and figure out at altitude if you really want more.  Remember your going to have a pretty heavy nose down pitch when you pull those flaperons on so make sure what ever you do that you have enough elevator to overcome it.  Getting another 5° of flaperon may be a mute point if you cant keep the nose up with elevator on approach without coming in with A LOT of power and getting the plane well behind the power curve.

:BC:

 

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Posted

Does the under camber wing need more Aileron? The reason I ask is the Kitfox 4 and up use 11degrees down and the early birds use like 20 degrees down

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Posted (edited)

Does the under camber wing need more Aileron? The reason I ask is the Kitfox 4 and up use 11degrees down and the early birds use like 20 degrees down

TJay,  This may be difference of why early birds had adverse yaw, and the later ones, starting with late Kitfox 3, (or maybe a retrofit to them), had differential ailerons with more up aileron than down?  I have designed aprox. 24 up and 12 down for mine.  EDMO

Edited by EDMO

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Posted (edited)

Jim, we thought the same thing, but you can't swap the two.  The pic doesn't show it, but there is another arm on that tube that makes swapping them impossible.

 

Leni,

I spent the first part of the day going through all of the old avid newsletters and found an article that basically said what you said in this thread, and that a lot of people weren't using flaps because of the pitch forward and the decrease in aileron control.

I could not find any numbers for degrees up and down of travel anywhere, other than rudder and elevator.

I'm taking Leni's advice and Im going with what I have.  With 10 degrees of flap I can still move the stick stop to stop.  Later if I find I need more I will re attack it.

Thanks for the ideas guys and I'll post any findings.

 

Ron

Edited by RDavidson
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Posted

On mine, I have it set to get all I can get on the flaperons, but then my control horns hit the turtle deck and limit roll control.  I do use full flaperons at times but thats in no wind or wind on the nose during landing scenarios (and take off).  If I have a cross wind I am more than likely only going to pull in 1/2 flaps.  Every situation is different and I fly as needed not any set pattern (ie spam can flying 10-15 degrees for take off, pull in XX degrees on down wind etc)  I use them as needed or as wanted.  You will figure this out at altitude what you are comfortable using and how much you can pull in before roll control is diminished to a degree that your no longer getting the warm and fuzzy feeling. 

Sorry that you are kind of hanging out in the breeze on this one, not sure if something happened to ChrisB or what as he is about the only guy I know on here with actual experience in the magnum.  He used to post a lot but seems to be MIA, maybe you can get a hold of him on PM.

:BC:

 

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Posted

Leni,

Thanks for the info...I pm'd Chris and sent him an email too, but he must be busy.  I know how that goes though, I just got to measuring my engine mount for a guy on the forum a year after he had asked for it!

It is sometimes hard to write what you are thinking, but hopefully this question will come out right...

Leni, you said earlier that your flapperons "are at 15 degrees down at full."

Does this mean your flap handle, when pulled fully, drops the flapperons 15 degrees and then you still have full left and right aileron input?

Assumption: Normal full aileron input = approx 20 degrees down on the down flapperon.

So in actual full movement of aileron input both sides would be dropping 15 degrees (flap handle input) plus an additional 20 degrees (approximate aileron down input) on the downward flapperon?  So you would be 35 degrees total deflection on the one flapperon...right?

 

I did feel a little better when I found a newsletter article that was written by a builder with multiple kit builds under his belt.  He said that he found the Magnum build manual to be of little help and that it lacked the detail of other kit manuals.  This is my first kit build and I was really surprised at how many times I've had to look at pics of other magnums to figure things out because the manual gave me nothing!  If it weren't for you guys I would be lost!

Thanks,

Ron

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Posted (edited)

Answering my own post again...I think I have developed a problem :)

Well I have identified part of the problem.  The directions said to mount the flapperon horn at 0 to -10 degrees, making sure that they cleared the sides when folded back.  They said -10 was desired.

I got about -7 to -8 degrees on each flapperon horn...that is screwing me!  When I try to set the flapperon at level (actual -2 to -3 degrees my horns bottom out on the frame instead of the control stops when imputing left and right.  The good news is that I'm still getting 25 degrees down and 20 degrees up.  Then when I move to half flaps I hit the control stick stops...same for full flaps.

So If I wanted to fix this from the start I would place the flapperon horns somewhere between 0 to -5 degrees.

Im staying with what I have, if I find I need more aileron when level then I'll come back and fix it, but I think it will be fine.

Thanks for all of the ideas guys, I tried all of them!

P.S.  I never want to install another cotter pin!  Between those sticking out and my plethora of zip tie ends, I look like I tried to drown a cat :lmao:

Edited by RDavidson
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