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Old Nov 17, 2007, 03:30 PM
One of the usual suspects
Vicarious's Avatar
United States, AL, Huntsville
Joined Jun 2007
1,470 Posts
Quote:
Originally Posted by tuppertn
Vic,
I'm surprised it turns at all on 3-channels without any dihedral. I built a scaled up BB and didn't put enough dihedral in the wing. It did a lot of tail wagging and very little turning. That was a KFm2 wing. Could the KFm3 wing have some characterisitc that allows a flat wing to fly RET without dihedral? Interesting. Tony...any ideas?

kendall
Quote:
Originally Posted by qban_flyer
Me likes the landing gear very much!

though I would be willing to bet that for a three channel trainer to behave as such, it should have some dihedral regardless of airfoil type.
Gee... I'm starting to feel like the cartoon character flapping his arms when he's told, "You can't fly! " ...except ...it does!

I looked all through this thread's pictures last week before I made my second wing. I thought I saw lots of KF wings with no dihedral and no ailerons. I thought that was the point... Maybe I did something wrong (I wouldn't bet against it. ) that turned out to be right.

Anyway, I got a nice PM from Dick Kline thanking me for my post. He likes that we are so open to using his great design.

Early yesterday morning, the wind was still, and I ran it across the cul-de-sac taking off over the empty lot, because I didn't want to crash again in front of anyone. All I knew was that it couldn't be any worse than the first wing. Well, it was nothing but great! My friend T3chdad flew it at lunch, and said, "Now it acts like a trainer." I'll try to take video before I add ailerons.

Jeff
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Old Nov 17, 2007, 04:04 PM
The Dude Abides
Beemus's Avatar
Brockport
Joined Sep 2005
315 Posts
Vicarios,
I am getting ready to post my new version as well, and I also extended the monobloc! Will have pics by tomorrow. Making a pair of floats too!

Did you build tip plates for your wing?
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Old Nov 17, 2007, 04:17 PM
I'm not flying backwards!
Tony65x55's Avatar
Oshawa, Canada
Joined Sep 2004
3,753 Posts
Jeff and Niels, congratulations on your flights.

Jeff, You did some neat stuff to the BB and I'm glad it worked out. I like the LG. Very original and would probably be terrific on the big, heavily loaded AP planes. Don't sweat on the dihedral thing. If it works, it works. Probably has to do with the generous side area of the plane...maybe?

Give the tip plates a try. In my experience they really add to that airfoil.

I know what you mean about the cartoon character being told he can't fly. When I started the development of the KFm foils a year and half ago I had many learned people telling me a KFm won't fly. Funny, I don't hear much from them now.

Beemus, looking forward to seeing your new plane.

Tony
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Old Nov 17, 2007, 04:53 PM
Always Ready!
warhead_71's Avatar
Chicago, IL
Joined Dec 2006
5,112 Posts
Just took the BB-48-KF1 out this afternoon in the rain and gusty 20mph winds. I wanted to try a bunch of different props on the BP2410-08y motor and I finally settled on one I like... a "Green" 9x6 (APC style prop) with 3mm hole (can't remember where I bought it: UH?, TH?, HL?). Well balanced, with good speed and ample thrust.

I had previously tried the following props:

11x4.7 - this prop was awesome... just enough thrust to hover, - until I burned out the motor

10x3.8 - great thrust, gains altitude steadily, but very slow top speed - difficult to maintain airspeed when flying with a tailwind, but I could recover quickly once I pointed into the wind. Good for dead calm or indoors only.

10x4.7 - a little less thrust and a little more speed - decent climb rate, not a bad choice in a slight breeze.

9x5 - better speed, but not enough thrust to maintain that speed - not as responsive when recovering from a maneuver or crosswinds, slower climb rate than the 10x4.7. Would probably fly better on a calmer day.

8x6 - better than the 9x5... a little faster... can do loops and rolls if I carry plenty of speed into it. Decent climb rate.

9x3.8 - underpowered, but long flights. Gaining altitude takes a lot of circling around, but then it will hang in the air. Not enough speed or thrust to do much aerobatics.
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Old Nov 17, 2007, 05:26 PM
White Mountains in NH
dlabrie's Avatar
In the White Mountains of NH
Joined Dec 2006
296 Posts
KFm3 42 wing

On my 42"BB, I have a Kfm2 wing made from 1/4"f oam, 10"chord, 5" folded over top portion resting on an arrow shaft about 1/4-3/8 thick. If I wanted to convert it to a KFm3 would I glue a 2 1/2" strip of foam behind the arrow shaft? It would come to about 1/2" ahead of the aielerons.

Here is a pict of the KFm2 wing.
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Old Nov 17, 2007, 05:33 PM
One of the usual suspects
Vicarious's Avatar
United States, AL, Huntsville
Joined Jun 2007
1,470 Posts
Quote:
Originally Posted by Truglodite
right, it's probably dihedral induced by flex or something like that.
No... When I said fiberglass rod in the leading edge of the wing, I was talking about a 1/4" bicycle flag being reused for 1 spar. The wing is straight and, pretty solid. (And actually pretty light.) Now the wing is like the rest of the plane. When I said it landed on the nose, well... The sound was a POP! like a VERY BIG kite auguring in. The fact that it wasn't a pile of foam peanuts blew me away!

Quote:
Originally Posted by Beemus
Did you build tip plates for your wing?
Quote:
Originally Posted by Tony65x55
Give the tip plates a try. In my experience they really add to that airfoil.
Tony
I may add tip plates - I haven't yet. Hard to mess with what works.

Funny, I almost went to the LHS and bought a foam wing for a Supercub or something that I knew would fly. I'm glad I didn't.
Jeff
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Old Nov 17, 2007, 05:43 PM
White Mountains in NH
dlabrie's Avatar
In the White Mountains of NH
Joined Dec 2006
296 Posts
Quote:
Originally Posted by Vicarious
Well, here's another Blu-Baby with a few original ideas thrown into the mix. ......... This took out the area for the landing gear, so I used an idea I got from the Dirt Cheap Parkflyer thread. The rest of the build was pretty normal.

Vicarious
Vicarious,
Great looking plane!
Could you give us a little more detail on the landing gear? How is the axel held in place?
thanks,
David
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Old Nov 17, 2007, 05:45 PM
I'm not flying backwards!
Tony65x55's Avatar
Oshawa, Canada
Joined Sep 2004
3,753 Posts
Quote:
Originally Posted by dlabrie
On my 42"BB, I have a Kfm2 wing made from 1/4"f oam, 10"chord, 5" folded over top portion resting on an arrow shaft about 1/4-3/8 thick. If I wanted to convert it to a KFm3 would I glue a 2 1/2" strip of foam behind the arrow shaft? It would come to about 1/2" ahead of the aielerons.

Here is a pict of the KFm2 wing.
Yep ,that would work just fine.

Tony
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Old Nov 17, 2007, 05:54 PM
White Mountains in NH
dlabrie's Avatar
In the White Mountains of NH
Joined Dec 2006
296 Posts
Quote:
Originally Posted by Tony65x55
Yep ,that would work just fine.

Tony
Thanks Tony. I will glue that strip on tonight.

I am having a ball playing with this. I had it up for a great fly today. I was doing loops and rolls. She was sweet! Then I started having some trouble with it wanting to dive. i landed her and found that the top control pin on the rudder, Pull-pull system was about to come out. She is in the hanger right now with a bit of gorilla glue on the pin

david
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Old Nov 17, 2007, 06:26 PM
One of the usual suspects
Vicarious's Avatar
United States, AL, Huntsville
Joined Jun 2007
1,470 Posts
Quote:
Originally Posted by dlabrie
Vicarious,
Great looking plane!
Could you give us a little more detail on the landing gear? How is the axel held in place?
thanks,
David
The landing gear is .062" music wire, and some GWS wheels - both from the LHS.
I put some finishing nails into a pine board at the points I measured and figured from the plane. Using pliers to hold one end, I could pull the wire into tight bends around the nails with my other hand. Result - 2 identical left and right pieces. The axle is a 6.5" piece of the same wire - held in place by 2 wheel collars on the outside.
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Old Nov 17, 2007, 07:22 PM
Postcards From The Purple Edge
tuppertn's Avatar
United States, OK, Sand Springs
Joined May 2007
3,919 Posts
Quote:
Originally Posted by Vicarious
Gee... I'm starting to feel like the cartoon character flapping his arms when he's told, "You can't fly! " ...except ...it does!

I looked all through this thread's pictures last week before I made my second wing. I thought I saw lots of KF wings with no dihedral and no ailerons. I thought that was the point... Maybe I did something wrong (I wouldn't bet against it. ) that turned out to be right.
I'm not trying to knock it. Like Tony said--if it works it works. I'm glad. I just wouldn't have expected it, that's all.
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Old Nov 17, 2007, 07:30 PM
Out the Window
High Flyin''s Avatar
United States, FL, Alachua
Joined Jul 2004
1,275 Posts
Quote:
Originally Posted by tuppertn
Hey, Ray, congratulations on on that BB. Sounds like you're having a blast. 18 minutes on 860mAh is nothing to be disappointed about. The 3s/1300 won't give quite as much more flying time as the mAh capacity may suggest because of the extra weight. You're talking about increasing your BB's weight by over 40%. Staying light is one of the secrets to endurance. Someone in this thread flew a ultralight 7oz BB32 for over an hour on a 2s/1300.

On a 2.2oz 2s/1300 TP Prolite my 10.2oz BB would go for about 24-28 minutes. On a 4oz 3s/1300 it only went 22 minutes (the power was there so I used it more). You just have to find the balance of what you want in terms of duration vs power. It's hard to get both.

Another 3-channel aerobatic maneuver that looks cool is the stall turn. Build up some airspeed in level flight then pitch up vertical. As the plane loses airspeed, throttle back and kick the rudder full one direction. The plane will "turn about its tail" and exit in a dive. It's a very graceful thing to watch if done with the right timing.

If you haven't seen Tony's SE5a then have a look. It's a simple, 3-channel, slow-flier bipe that's gotten rave reviews. Mine's in mid-build right now.

kendall
Kendall

Yes, I am having a blast with the BB. Thank you for the information on the batteries. I had not thought that a couple of oz. would make that much difference. The SE5A does look good, should be a good one since Tony designed it! My batteries are all charged up and maybe I can get some flight time in tomorrow, if I do I will sure try the stall turn.

Quote:
Originally Posted by Tony65x55
HI Ray, I assume from your BB's all up weight that it is the 33". You don't say if it has the UC wing or the KFm wing. The plane will have little trouble with the larger battery but I strongly recommend a pair of wing struts to support the extra weight. The 33" is designed as a primary trainer with a very low wing loading and while the plane will handle much larger amounts of weight easily a little wing strengthening is in order.

Your 33" BB is not designed to be aerobatic and so, outside loops are a little more than it was designed for. The addition of the KFm2 wing for it will turn it into a superb advanced trainer capable of all basic aerobatics.

If you want a really nice, easy to fly biplane, take a good look at my SE5a biplane. It is a simple rudder/elevator plane that builds the same way as the Blu-Baby and shares it's easy to fly characteristics.

Tony
Tony,

Yes, I built the 33" with the UC wing, and it is a pleasure to fly! Thank you for the great plans and all of the help you are giving to builders here on the forum. I used your bent popsicle stick idea to help strengthen the wing. I also added two full length (about 11 inch) bamboo sticks down both wings. The popsicle stick and bamboo sticks were all glued to the bottom of the wings with Gorrila Glue. The wing seems to be very strong. I have tried some crazy things, had a few hard landings, hit a chain link fence head on and the wing looks like new.

The SE5A sure looks good....love the biplanes. I am also drawn to the lager size Blu-Baby plans with KFM3 wings.

Thanks again,
Ray
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Old Nov 17, 2007, 07:34 PM
Out the Window
High Flyin''s Avatar
United States, FL, Alachua
Joined Jul 2004
1,275 Posts
How are people here getting such straight good looking leading edge bends for the KFM wings in Protection Board. The factory bend on the bundle I got looks kind of bumpy.
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Old Nov 17, 2007, 07:45 PM
One of the usual suspects
Vicarious's Avatar
United States, AL, Huntsville
Joined Jun 2007
1,470 Posts
Quote:
Originally Posted by High Flyin'
How are people here getting such straight good looking leading edge bends for the KFM wings in Protection Board. The factory bend on the bundle I got looks kind of bumpy.
I learned from Gene Bond.
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Old Nov 17, 2007, 07:47 PM
I'm not flying backwards!
Tony65x55's Avatar
Oshawa, Canada
Joined Sep 2004
3,753 Posts
Quote:
Originally Posted by High Flyin'
How are people here getting such straight good looking leading edge bends for the KFM wings in Protection Board. The factory bend on the bundle I got looks kind of bumpy.
You need this!

Tony
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