THe Cap for me was snapping always in one direction, to the right . It wasn't bad either - it usually rolled less than 90 deg. I'm not even sure it was a snap, since it wasn't instantaneous, and I could counter it with aileron.

I had taken all the steps mentioned here, incidence check, lateral balance, small elevator throw, turbulators. However - I started slowly increasing elevator because throw was so low I wasn't comfortable landing it. Pull too much in a left turn, no big deal. Pull too much in a right turn, it'd go over on it's back.

I was getting a handle on nice landings, doing touch & goes when the engine quit on takeoff at 45 deg nose up. Round over the top and pull back hard - no luck. It didn't snap anyways, but it did pancake, hard. One of the wing panels busted in half and flew up in the air. Broke the spark plug off at the base of the ceramic.

It would be reparable if I was interested in trying to true it up - but this plane had too much "personality" plus it was built way tail heavy. I had to put a pound of lead in the nose, along with my Brison 3.2 to get it to balance. I'd rather start over with a kit I can build light & straight from the beginning. I went to Aerowork's site to look at their 29% Edge - and they don't make it anymore

Anybody in the Central Florida area want a project? Needs a new wing panel, cockpit canopy, and cowl - available from Lanier. Otherwise, needs a few things on the fuselage tighened up and some scrape - repair. You can have it for free....

Sorry to hear about your pancake but dont feel to bad Ive got a H9 Edge with the same problems and a Friends got a WM Extra doing it to.
Both are in the shop for repairs.!!!

ALL of the " snapping problems " I have seen on these designs --is caused by one thing.
The durn model is just too friggn heavy.
Snappin Caps -originated with the first GP Caps from years back -- they were also WAAY too heavy.
Caps setup at 25% of chord balance- with reasonable wing loadings are super flyers.
I have built kits in various sizes as well as designed them from .40 cu in engine size to 150 cc size
The full scale Cap has had long and short wing setups (Cap 21 -- CAP 232)- all will snap if heavily loaded.
the scale stab setups are both forward and relatively small.
Anyway - the majority of the BARFS I have seen --are overweight -and all of the hinge line sealing etc ., will not solve that problem.
Speed and careful control inputs will keep the abrupt snap from starting --

The WM Extra I mentioned is only running an OS 1.6 and single batt pack I fail to see how you could run it any lighter without some serious design changes and theres not much to the WM Extra.
The GP Extra is heavier and I have seen it on gas just sit there and float. When it stalls it just mushes over.
The Edge will float in if you let it and thats not when it snaps.
i see what your saying but I cant believe that the case in all instances.
I have a Giant Stinger that is a porker and it has none of those bad habits doesnt matter how you fly it so some of it is wing design.

start with correct cg then lateral balance then make sure your tail pulls up equally on the stabs and follow conservative settings on the up until you know the plane then give bigger throws etc. the problem is, is that we want to 3d these planes to fast.

Edge has much more tail moment --better stability -
Stinger has much more chord - effective lower aspect ratio -
different ball games --

Dick thats a bit of a sweeping statement



ALL of the " snapping problems " I have seen on these designs --is caused by one thing.
The durn model is just too friggn heavy.

The lightest of the ones I mentioned is the worst snapper.
NOT the heaviest.

well - I don't know what weight ranges are on each of the models you have - .
The problems on all of the kits I have seen are directly related to high wing loading.
Loading is -on the ARFS - typically at the max for flying most aerobatic stuff.
On a Cap - it is easy to get the loading too high.
On a " Stinger type "- the loading can be a bit higher.
I see -typically - 1000 sq in ARF models --with wing loadings in the 30's -
tho these will fly --and can be coaxed into large open maneuvers -- the wing loading on a GOOD 1000 sq in aerobat is much better around 22-25 oz ft.
These setups can stand much more yanking around --
I stand by my comment- most are simply too heavy --and many of the heavy ones are tail heavy -
and most of these are ARFS

Dick,

1000 sq.in. wing with 74" wing span and 25 oz per sq. ft. loading would be about 11lbs. right?

What model and engine are you talking about?

RD

Hey Chriss,
What are turbulators?
And is giving the engine a couple of degrees up always necessary?
And if not how will I know? Will I be able to fly it?
I know a guy who has the same Cap I'm getting and has the same setup
I will,, His plane only weighs 7lbs,, is that too heavy?
The plane I will be getting is the Kangke Cap 232 60 size 62" wing. ARF

Paul,

Tubulators are actually devices that create vorticies on the wing that keep the boundry layer attatched. This helps to improve the efficiency of the wing, especially at low speeds (high AOA). Some full sized planes even have them on the prop!
The correct term for what we're talking about is a cuff, or slat. Generally speaking we're sticking something on the leading edge of the wing to increase the chord at the tip. This is to (hopefully) keep the tip flying when the root stalls. We can do this by decreasing the angle of attack on the tip (washout), or increasing the tip chord. Additionally, the large scale guys figured out that a blunt leading edge stalls "softer" than a sharp leading edge. For your airplane you could take a 12" piece of 1/2" square stock and just tape it on the leading edge at the tip. It works, but I don't use them, I'll usually try to get rid of weight first.
Not all Caps need the up thrust, the 1/4 scale just happens to. You'll know if yours does if the CG is within the normal range but the plane climbs while inverted or pitches up with the power off.
From what I've heard the Kange Cap is a great flying plane, I wouldn't expect any problems, just keep it light. Don't put a heavy engine, big fuel tank, dual servo's or lead on it. Just fly it, leave the leading edge cuffs for another time when you're bored.

Chris

pattern designs fall into the 25 oz ft region-
I design/scratch most of my planes -so I do the IMAC stuff in the same wing loadings -- huge difference as compared to the heavy stuff.
Look for better wing loadings as the BARF importers get their crappola together.

not worth the comment.

Dick, when is the 100" Dalotel going to be out? Your small version looks quite light for its size and if its as good as you say it is, I can't wait to see how you like the larger version!

I have just finished building a Kange Cap, I really don't even know if kangke has the right denomination for this plane, since they claim it is a Cap 232 while the color scheme and everything is related to the 231 EX. Anyway before buying the related items for the plane I read several posts on the plane and I thing I did good doing this first. Apparently this plane was found by everyone tail heavy so a lot of weight was to be added if you used the recommended engine sizes. The plane can take (apparently) a .90 engine, but if you do a little searching you can see that many people are installing bigger engines to avoid adding weight. I personally installed a TT 120 Pro with pump and pitts muffler. Although I have this big engine up front, and I have less weight on the tail because I used a dubro pull-pull on the rudder, I am still tail heavy, not much but I still have to put the battery pack, a 6V 2000Mah, forward of the CG by at least 2!QUOT!. No added weight other than that but this plane is tail heavy, A LOT. I haven't tried it yet since I am waiting for some hi- torque servos for the rudder and the elevator. I think it is a really nice plane, and by the way the total weight of it is about 8.8 lb so I am a bit heavy but I can't seem to understand how could I have less weight respecting the CG.

I don't want to speak for anyone but.... I think that Dick and I are pretty similar in that we'll go to extreme measures to get the weight out. Including; lightening of the airframe (removing wood), rebuilding lighter constructed tail surfaces (sheeting over foam or hand selected balsa), lighter ailerons, smaller/lighter hardware, lighter gear, less servo's.
A couple of possibilities for you might be to move the elevator servo's up under the canopy with carbon pushrods, or better yet, pull-pull. On my 1/4 Cap's I used an MK bellcrank for elevator with 1 servo driving it, a 9304 on 6V. Get the lightest tailwheel possible. Remember 1oz in the tail equals 3-4oz in the nose to balance. I've even skeletonized the ribs in the tail to get it lighter. Definitely get the battery pack in the nose.
Look for one of Dick's construction photo's or the Troy Built Models Extra build to see lightening in action. I built the entire front half of a H9 Cap out of carbon and made a flat plate (Q400 style) motor mount just so that I could get a Moki 2.1 in there without a weight penalty or CG change. (It helps when terra firma removes the nose for you to begin with).

Chris

Turbulators, slots and slats are all somewhat different beasts, and are used in a variety of ways on modern aircraft.

Turbulators, Vortex Generators, Vortelons are all in a group that, by inducing vorticies on the surface, prevent airflow seperation. The increased energy on the surface is used to increase control responce (when used in front of a control surface) and in the case of vortex generators across the entire wing, increase lift at medium to high AOA flight.

Slots, both fixed and movable, allow high pressure air from the lower leading edge to pass through to the top side at higher velocity than the natural airflow over the wing, thus allowing flight at higher than non slat wings. This would happen with no increase of chord.
Slotted flaps also take benefit from this principle.

Slats work both in the slotted role and the "sealed" role. The sealed role is an increase in chord, but more importantly is a huge increase in camber, thus increasing lift for a given airspeed.

As for snappy caps, I'm in the make sure it's straight and balanced camp. I also like to do power off stalls to see which wing drops to look at the airframe and exclude any thrust questions before chasing power on snaps.

Les