Andrew_S

My Feedback: (12)

I figured it out as soon as it took to the air. It pretty much went straight up, and started porposing up and down..I quickly fed all the down trim in it but didnt help much at all..I moved the iginition battery up to the standoffs after that incident and it helped some...I then bought a heavier spinner and that pretty much too care of it...It actually sounds like yours is nose heavy...When I reduce the throttle on mine it will slowly start dropping the nose.

I've probably got an inch or so of throw up on mine..I started up with probably 1/2 " but I ran out of elevator when I tried to land with the flaps on...I have 30% expo dialed in on mine now too...

kahloq

DO NOT under any circumstances put your CG at 135mm. If you do, you will lose your plane. 125 mm is almost too tail heavy as well, but flyable. I know 135 is way too far aft cuz I had mine at 128mm, and it was tail heavy.

kwik

Okay. Very good info from you guys here now!

Here is what I will try;

I have drilled a 4 mm hole in the wing-spar at 12.5 mm ( near the upper wing-skin). I put in one screw in each wing so the screw head protrudes.

I hang up the plane in these screws using a thin wire. Then I slide on the outer wing-panels.

It will then hang slightly nose down. I will put in just a little lead in the tail so its a little bit less nose heavy in this position.

This time I will take off with the same max elevetator and 30% expo.

I will have another setting with 75% of that max, 30% expo.

Then we will see.

When I get this right, I will have lots of fun!! Still some summer left.

Andrew_S

My Feedback: (12)

Very true...I found this out from first hand experience...

Good luck kwik and keep us posted...

damagedgoodes

Meaning no disrespect to any members here I must disagree about the C of G coments. I have been flying mine at various C of G settings and have settled on 128mm for my aircraft. I think something that is being overlooked is the incidence people have between the ailerons/flaps as it is not covered in the manual and two slightly different settings will make two very different aircraft. I've found through trial and error that the best setting is to have the ailerons/flaps parallel to the chord line of the wing when viewed from the wingtip. If they are set slightly low (in the off position) they will act as flaps and create lift on the wing. As the aircraft gains speed they produce more lift and cause the aircraft to climb. Some would think engine thrust line is off and not enough down thrust is built in. The pilot trims for a lot of nose down for level flight at a higher throttle setting to compensate. If your not happy with this reasearch centre of gravity and the relationship of centre of pressure of a wing and how the centre of pressure moves fore/aft on a wing with changes in airspeed and angle of attack. As the aircraft slows down, the extra lift and pitch being produced by the wing decay's and the aircraft pitches nose down. That's what it look like to me in Kwik's videos as I've produced the same result with my Stuka by having the flaps/ailerons a few degrees lower. Add to that a heavy G-38 installed which will increase the wing loading of the aircraft and it looks like a tail heavy model. My Stuka is 14.7lbs and flies like it's on rails, lands at walking pace with or without flaps and is not pitchy at all at 128mm. Kwik, try setting your flaps so they are up as much as they can go in the "off" position, that way they will not be having an adverse reaction to the airframe and see how you go. The Stuka has a relatively small elevator. If you go more nose heavy, you may run out of elevator autority on landing, as the nose havy condition will not be balanced by the tail at a low airspeed. I will post pictures tonight when I get home showing my flap to wing incidence as well as the elevator thows I fly with. Cheers,
Dave

kwik

Thank you Dave. This sounds very logical to what I have seen.

The plane wont go down even at the lowest rpm setting, and when it finally does, the nose dips violently down.

Obviously it wouldnt drop the nose if it was tail-heavy.

That aileron setting on zero is really interesting.

Up in the air the plane is wonderful. I have problems on the final sequence.

It is problematic getting the G-38 to idle lower than 1500 rpm without stopping.

So its different from being under-powered. I need less lift.

damagedgoodes

Kwik,
My travel for the elevator is 10mm up/down on low rates with 20% expo (used for landing and take-off) and 17mm up/down on high rates. Attached are pics of my aileron/flaps to show how the chord line of the control surface (flap and aileron) are parallel to the chord line of the wing at the wing tip. Cheers,
Dave

kwik

Dave, I think you have helped me enormously here now. Thank you so much!!!!!!!!!!!!!!

It fits. Too much lift...speed down....a bit heavy nose.....not enough elevator...

damagedgoodes

Hope it helps. You really don't want the ailerons/flaps creating lift on the wing as it will change the way the plane flies throughout the whole speed envelope. What does your plane weigh out of curiosity? From watching your You Tube video it comes in pretty quick which makes me think the wing loading is quite high. Cheers,
Dave

TomCrump

I was thinking the same thing. It looked, to me, that kwik's Stuka flies like it has a high wing loading.

Andrew_S

My Feedback: (12)

I was also wondering about those fake dive brakes on the front of the wing, thinking they may be causing some kind of lift...I have mine installed with the 3 angled mounts toward the back of the wing....Kwik and Dave, did you leave yours off?

kwik

Andrew, my Stuka shredded them on the second attempt.....automatically.

I will leave them off until these landing-matters are fixed. Then I will start with sirene, bomb, sliding canopy and all that.

Until then such matters are... given low priority.

Andrew_S

My Feedback: (12)

I'm scared to ask how it shredded them.....I guess the dive brakes have no effect then...I did the sliding canopy thing...make sure you make some kind of sturdy frame to support the canopy or it will shake from side to side..I used the canopy rails with ball studs from NCIS along with some thin brass running along the bottom of the front canopy...Later on I made a frame out or brass tube and epoxied that to the inside front of the canopy...

kwik

Yes, I have the same rails waiting. If I dont stiffen that canopy with some framing, it will be just like an electron.

You know it is in a certain area, but you cannot see it.

Andrew_S

My Feedback: (12)

I was just watching your video...Looks like the flaps are a little bit down compared to the ailerons..And the way it drops the nose when you reduce throttle makes me think it is a lot nose heavy...Mine weighs a little less than 16 pounds and it doesn't drop the nose anywhere near what yours does...I actually have to push a tiny bit of down to get it point down..

kwik

Doublechecked everything now.

The ailerons already was / is paralell to the wing chord already.

Yes I had a little flaps out.

The CG is in fact at 13 cm already. When hanging at 13 cm absolute level, and I let it go, it slightly tips forwards.

10 more grams in the tail makes it absolute level.

It weights 8.5 Kg.

Andrew_S

My Feedback: (12)

How bad was the damage to the wing from the landing gear gettin pulled out? Nothing serious I hope.

damagedgoodes

My you have a fat little piggy there...mines 6.7 kg. I really think that 4 pound difference between our aircraft is why your Stuka is behaving like it is. I hope getting rid of that bit of flap will help. Best of luck,
Dave

kwik

Okay, new Info:

I balanced the plane at exactly 13.5 cm. See picture below.

Adding 50g to the tail and it moved CG 0.5 cm back to 13.5 cm.

Another thing; I set elevator max to 1 cm up with 20% expo. (The old max was 1.7 ; WAY to much)


I went of to the airfield at taxied out. And throttled up. The plane lifted the tail and I had the most wonderful takeoff.

I flied back and forth, testing throttling down, flying slow, flying fast. Some slow flypasts. All looked well.

Time for landing. The plane performed perfectly. I could throttle down without the nosedive, and greased it in for a perfect landing.

Sloooooow landing. Perfect! 8.5 kg is ok for that wing.

You wont believe how good it felt. I am so happy!

damagedgoodes

Kwik,
Congratulations, I'm really happy for you. Must feel like a totally different aircraft. Enjoy your Stuka (now just get some wheel pants, it looks like it has chicken legs )
Dave.


PS, if you want you can get yourself one of those Great Planes C of G machines ( they work on aircaft up to about 30lbs or so ) and are really easy to use, very accurate and a great for doing warbirds with retracts upside down.

fockewulf37

My Feedback: (102)

Hey Guys,
I finally got all the other cockpits out of the way. I now have time to revisit the Stuka and do one for the B model. I did have time to make a mold for the canopy. I had to make it 2 part canopy due to its length. It is pullled from .040 PETG. It is nice and clear and is alot more flexable than the original. It has a big overlap and should be easy to join at a frame joint. It would be great for anyone wanting to make an open canopy. It will be available from VQ Warbirds....

Ty

fockewulf37

My Feedback: (102)

Hey guy,
I finally got to work on the B model stuka cockpit. I could not find the B model color scheme of this particular model to find out exactly the armoured plating it used. I went back to the stuka walk around and found pic's of the different ones used.. Away here are pic's of what I came up with.

Ty

fockewulf37

My Feedback: (102)

Here are the pic's of the finished cockpit. I the rear gun can be placed anywhere you want in the rear canopy. There is also a small handle that is supplied that is glued opisite the gun. The original canopy painted the whole glass bulgeover and the real one was clear. Here is also the short B model video for installation of the Cockpit.

http://www.youtube.com/watch?v=ZyhVNYKq7Gc

Ty

Andrew_S

My Feedback: (12)

Ok guys, I am putting the finishing touches on a cockpit install...It came from vqwarbirds/Ty...I must say this is an awesome addition to the Stuka...Thanks Ty for a great product ...Now, I have to decide if I want a pilot figure or not...If I stick one in there it might hide some of the scale details in the cockpit such as the flap wheel and the switches..And if I dont put him in, it will look goofy flying around...So what should I do? I'm not doing a sliding canopy and I'm not planning on putting a pilot in the rear.. I took an esm pilot bust and cut his shoulders down..I found an old tan gi joe jumpsuit and stuffed it with foam. I took an old doll and removed the arms and have them in the sleeves..No feet since they will be stuck under the instrument panel. It looks pretty good I think...

irocbsa

My Feedback: (12)

Looking good Andrew. The cockpit really ads a "wow" factor to the plane that just isn't there without it.

Have you been able to get your engine to run reliably? I've had nothing but trouble with mine. I ordered a replacement carb that will hopefully fix the fuel draw problem. I've done everything in the world to fix it and nothing worked. I rebuilt the whole thing this weekend and replumbed the tank lines as well but it still won't pump. Seems like others are having the exact same issues, including a guy at my club.