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Old Nov 14, 2012, 03:43 AM
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Quote:
Originally Posted by sir_clive View Post
she looks great! video, video!
Thanks sir_clive

here

Blu-baby DIY plane flight (1 min 7 sec)
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Old Nov 17, 2012, 06:14 PM
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KFm2 BB 33 inch Plans


Hi:

Where would there be plans for the 33 in. BB with a KFm2 wing?

I really need the plans for the fuse sides which provide the wings chord length and, most importantly, its incidence angle. I supose it would have the same dihedral as the 4-40 (under-cambered) wing.

TIA
- Jim
Old Nov 17, 2012, 10:46 PM
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Jim,
The standard BB33 plan has the KFm2 option on it. You just cut the wing saddle flat to zero degrees incidence.

Ken
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Old Nov 18, 2012, 08:06 AM
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Quote:
Originally Posted by JimHSoars View Post
Hi:

Where would there be plans for the 33 in. BB with a KFm2 wing?

I really need the plans for the fuse sides which provide the wings chord length and, most importantly, its incidence angle. I supose it would have the same dihedral as the 4-40 (under-cambered) wing.

TIA
- Jim
This thread has lists of all of the BB 33 plans and also a lot of other useful info about the BB 33, various KF builds, and other Tony65x55 builds. -

** Tony65x55 ** planes and plans - https://www.rcgroups.com/forums/showthread.php?t=997484

The originator of the thread is no longer active, the thread is not a sticky, so it keeps fading into the background here. But when someone wants to find plans for the BB 33 it is one of the best places to get started.

If people agree as to it's usefulness, they will petition the moderators to make it a sticky thread. Or, if someone wanted to go forward with Hopalong_x's good work, they would start a new version of the thread and take the information forward.

Jack
Old Nov 21, 2012, 12:25 PM
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I don't know if anybody has a quick answer.....

I'm putting the final touches on a new 42 BB with the wing saddle and the under cambered wing. I have some Nephews coming for Thanksgiving dinner and my plan is to put the buddy box in everybody's hands at least once!

What I can't find is the C/G for the under cambered wing. Unless somebody says different, I'm just going to make it the same as for the KFM wing. I've kind of run out of time for a test flight so if it crashes on the maiden the boys will also get a lesson in disappointment. Of course I still have my original BB as a back up but it's starting to look a bit shabby.
Old Nov 21, 2012, 12:56 PM
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It is on the plans as 2.3" to 2.6" back from the leading edge. As I'm sure you know, too far forward is better than too far back.

Nose heavy might fly badly, tail heavy might fly only once...

Good luck with it!

Jack
Old Nov 21, 2012, 01:01 PM
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Thank you Jack.


Quote:
Originally Posted by jackerbes View Post
It is on the plans as 2.3" to 2.6" back from the leading edge. As I'm sure you know, too far forward is better than too far back.

Nose heavy might fly badly, tail heavy might fly only once...

Good luck with it!

Jack
I'm sure someone will have a camera so if it goes well I'll have pictures to post and maybe even some video.
Old Nov 26, 2012, 06:21 AM
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My scratchbuild flew!!!
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Hi all

My BB 33 kfm3 has come in just over 18oz and the original motor/prop combo planned was a BW1700 8x4 on 2 cell. The motor specs read approx 13.6oz thrust for this 2S setup.

What could I realistically expect from a thrust ratio of around 0.70:1? Will it actually get off the ground?!??
Old Nov 26, 2012, 07:22 AM
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0.33 to 1 is considered the minimum for a thrust to weight ratio. But 0.5 to 1 is enough to get you into the sports/basic aerobatic power range and 1 to 1 is enough for 3D. So you should be fine.

Jack
Old Nov 26, 2012, 11:31 AM
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Duplicate post.
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Old Nov 26, 2012, 11:32 AM
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Of course, while taxiing, it also depends on the size of your wheels with respect to the roughiness of the runway. But if it doesn't take off, you can always give it a toss.

I don't think my thrust:weight ratio on a 3s bb42 with cf2822 is any better than yours and she flies great.
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Old Nov 26, 2012, 12:17 PM
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I agree with Jac and Clive . My last BB came in pretty hefty and runs the same power system as you . Not a power house but plenty of power to fly .
Old Nov 26, 2012, 06:18 PM
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My scratchbuild flew!!!
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Thanks all, will stick with the BW1700
Old Nov 26, 2012, 08:22 PM
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That should fly it, but I'd be thinking 3S and 7X6 prop for a little more fun and ability to get out of trouble.
Old Nov 30, 2012, 12:58 PM
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Wing Trouble of the 42" UC variety.


My Thanksgiving Day Foam Fest was a bit of a bust. The 42 inch under cambered wing folded up after about 30 seconds of beautiful, slow, graceful flight. I was heart broken because it looked like this was going to be the perfect plane for my Nephews to fly.

I'm looking for some help in building the next wing so I don't repeat the crash. Here are the details:

FFF cut per the plans and manually bent into shape.

Steam bent 3/16" dowels in the leading and trailing edges

Center seam glued and reinforced with Fiber Glass tape and epoxy.

The break was a couple of inches outside the wing saddle on the starboard side and both the leading and trailing dowels split.

What's killing me, is this is basically the same wing I built for the SeaBB and it's got a couple of dozen flights on it without problem. However, now I'm afraid to fly it.

Thicker dowels? More tape?


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