Rhett,
As of yet on the pa 18 layout we haven't seen any change good or bad,
except better visibility. Wayne
Rhett,
As of yet on the pa 18 layout we haven't seen any change good or bad,
except better visibility. Wayne
Stolmaster
Thanks Wayne
I need all the help I can get!
BC-12 Don't forget that lowering the engine 2-4" will also lower the prop tips 2-4" closer to the ground.
N1PA
Yep made a pair when I built my cub but Wag-Aero never had any info about attaching them to the wing other than the comment (just screw them to the capstrips). not on my 1/4 inch wood cap strips. I still have them in a box somewhere. Cliff
I just finished my second exp pa-12, and while we are talking wing mods here is what i did,it is an extended wing with 8'flaps and 8' ailerons, fences,VG'S and a cuff on the out board 8'. the reason i only put the cuff on the last 8' was to keep the inboard section of the wing stalling first thus there should be little to no tendency to drop a wing in slow flight as the root would stall first.20% of my flying is on skis 80% on floats so the slats wouldn't be a big help to me.Thoughts?
i would post a pic but i still haven't figured out how yet so if someone pm's me i'll send them one to post.
Originally Posted by cub12
Glenn
Slotted Bushmaster:
Nice cub I like that clean looking cowl. and if your going to cover the gear legs that's a great idea half way so the step is easier to use looks like alum. half wing cuff interesting.
DW
yep alum,it is nice to be able to put your foot through the gear leg especially with big boots on.Many mods on that plane it has an 0360 with 9.5/1 pistons,pmag,sutton exhaust catto 86/38.thrustline mnt ect.the airframe is from BCC done by Jay at Javeron.Cloude G's stamped ribs. i am hoping to do the first flight next week!
As long as this thread was brought back to life, Last week I put wickerbills on my 2+2, with no flaps I need all the help I can get. Over the years I'v talked to Dave Calkins and recently, Jim C. and decided to give them a try. I only have an hour and 15 or so landings and it was a little gusty at the time. I do feel a difference when slow and I think it cut my cruise speed some but not much. I put them from the fuselage to the aileron and from the aileron to the wing tip. I don't have any numbers yet but the seat of the pants feel is very noticeable. I used .040 3/4" X 1" with the 3/4 hanging down. Tomorrow the sun is supposed to shine and not much wind so I'll give it a go and try to get some numbers. And some pictures
Tim, note how much the ailerons get deflected up in cruise. I am curious. It was necessary to rig both ailerons quite a bit down with wickerbills on the ailerons. I removed them eventually and did not reinstall them to the ailerons.
I suggested to Tim that he not put wickerbills on the ailerons because of the reflex, and I don't think he did.
JimC
No I did not put them on the ailerons after reading about the reflex. So far so good I like the way the airplane feels with them.
Tim
The underlined sentence confused me on the first read.
So do you have a short wickerbill from the outboard end of the aileron to the wing tip?
Yes.
Inhibits tipstall but increases the intensity of the tip vortex.
Is it worth the cruise drag I assume is present?
Yes.
Im asking if the short wickerbill near the tip is worth the cruise drag.
how long is this wickerbill? can you quantify its performance increase and cruise speed reduction? thanks
Tim can tell you the exact length. To quantify it, I'd need a few parameters on his specific plane. Qualitatively, I'd expect it to cost him roughly about a tenth or so of a mile per hour in cruise.
Since the inboard wickerbills are loading his tips more heavily than before, the purpose of the outboard wickerbills is to increase the circulation on the outboard wing and defer the tipstall. Wthout them and with the inboard wickerbills, the asymmetric tipstall break can get nasty. It's a safety issue.
I did not find an issue on the Cuby I was playing with.
Still haven't got any good numbers. Today I flew about an hour and a quarter north to a friends with a pretty good head wind so don't know on cruise speed. All I know so far is it feels better on landing.
Tim
Dave, I'm glad you didn't find it to be an issue with that Cuby.
Jim, it was round tips. I did wickerbills on ailerons, then took them off. That thing had no problem. It was sweet.
Have you found nasty habits without a device near the tip? what kind of habits?
Tim, what was your airspeed compared to before wickerbills? Headwind or not, your cruise airspeed before and after wickerbill installation is a valid number.
Last edited by Dave Calkins; 03-10-2013 at 08:20 PM.
Well, the only nasty habit I'm aware of is the rather substantial potential to stall one wingtip and aileron at low altitude with high power settings and high angle of attack while the other wingtip and aileron remain unstalled. the consequent abrupt drop of one wing can be entertaining if you don't have a lot of altitude to play with. I prefer (when feasible) that the wingroots stall before the tips.
Headwind doesn't make any difference to cruise measurements, but the turbulence often associated with winds sure does.
Flew an hour and a quarter home today. At 2500 and 23 inches I was seeing 85 to 87kts (indicated) at 3500ft. That's just about what I see without the wickerbills. I'm sure they scrub some speed off, but damn little. I'm so impressed with the way the plane feels in slow flight, and when landing, I'm going to leave them on. I think I'll leave them on for 50 hours then take them off and see how the plane feels then.
Tim
Last edited by Tim; 03-11-2013 at 06:50 AM.
Thanks for the report Tim. Good stuff
Bill
Very Blessed.
Finally after another foot of snow and high winds for the last few days I FLEW C-FMHF for the fist time YAHOO!! I didn't do any stalls ect, just flew around for an hour break'en in the motor. it flies great what a monster! cruise with the catto 86/40 was 112mph climb at 75mph gave me 1500fpm and the engine ran smoooth. I"ll post some stall numbers soon
I know I need flaps but you guys are making me think about wickerbills again. The extra weight and complexity of flaps makes me go back to the no flap mind set...I've gotta fight it off and build flaps!
Somewhere along the way I have lost the ability to act politically correct. If you should find it, please feel free to keep it.
go with flaps.
See....I knew I was right!!
I bought ribs and they just arrived yesterday and the are pretty nice. I'm going to use the aileron ribs as a model and make the flap ribs out of .032 instead of .020 they used for the ailerons and use a torque tube to operate them with an overhead handle. I'm thinking of using 3/8" rod ends for hinges but I haven't run that by my IA yet so my idea might change.
Keep me on the straight path Dave!
Somewhere along the way I have lost the ability to act politically correct. If you should find it, please feel free to keep it.
Place the hinge point below the flap, like a Super Cub. This way when the flap moves downward a gap will open up between the flap and the wing. This gap will act the same as slots on the leading edge by smoothing the airflow over the top of the flap thus delaying the flow separation. This generates more lift at maximum deflection.
N1PA
That's a good thought Sky. I never really thought of it that way...adding lift by keeping the airflow tight against the top of the flap. That warrants more thought and research...Thanks!!
Somewhere along the way I have lost the ability to act politically correct. If you should find it, please feel free to keep it.
on our metro's their are VG'S on the flaps to help
My Cub's flaps are 110" long. I took great care to make a gap closing fairing, along the top trailing edge, (when retracted) out of balsa wood and fabric. This has nice smooth flow along the cove of the wing to a sharp trailing edge. As a result I seem to be getting good slot effect action over the flaps. The lift of these flaps is so great with the power off that it embarrasses me. The plane could use spoilers to help it come down. I tried increasing the maximum angle. It still floats. That is telling me that the slot is helping the air stick to the flaps. I haven't tried tuff testing.
N1PA
Flap ribs out of .032 is a bit heavy 2024 t3 .020 is plenty strong and a lot lighter.
I tried this. No gain was realized. Jerry Burr concurred that the flow through the slot is already so turbulent that organizing it with VG's and causing it to make the curve to follow the back side of the flap was unlikely.
Some type of curved device, or what Skywagon did may have a better effect. Skywagon, do you photos of your trailing edges?? I would like to see that. Did you test with it and without it?? what results?? Thanks.D
just got down from doing some stalls and slow flight, It feels really nice at 50mph the cuffs work well. However i could not get the plane to stall with flaps up or down, flaps up it started to sink at about 40 and down was about 37. compared to my other smith 12 this one is nose heavy even with the engine mount pulled back 4",light weight starter and alt,catto prop, i am landing with full nose up trim and the stick all the way back. I have VG's under the tail plus the little fins by the stab. I am thinking cubcrafters gap seals? i think the plane should fly slower if i had more elevator.even at 40 it did not buffet good control and no tendency to try and drop a wing.That being said cruise is way faster then i expected. also i the main wings i have the VG's, fences, and gap seals on the top for both flap and aileron and the cuff on the out board 8' of wing so what should be a realistic stall speed?thoughts please.Thanks
.020 just looks so flimsy....OK for ailerons but I thought there was a need for heavier on flaps when I want 40 degrees.
Somewhere along the way I have lost the ability to act politically correct. If you should find it, please feel free to keep it.
Dave, Send me a pm with your E mail address. I'll scan some photos to you. They are film pictures which I have been unable to post here. No, I did not do a before and after test as they were done during my building process. They are similar to Piper's shape except they have a longer more sweeping arc. It would be interesting to tuff the flaps with yarn and mount a camera on the tail to see what happens. The lift is so great now that I suspect that the airflow is doing a good job of sticking to the flaps.
N1PA
Thanks. I sent you a PM.
I would be doing a Keller flap for any experimental Cub type.
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