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Old Jul 20, 2008, 11:40 PM
I'm not flying backwards!
Tony65x55's Avatar
Oshawa, Canada
Joined Sep 2004
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Quote:
Originally Posted by Hopalong X
All I needed was a bit more motor.

Who knew Tony's BB was capable of supersonic.

Thanks for the great plane Tony.

Mike
Fantastic! I knew someone would dig up that old pic of Yeager breaking the sound barrier in his full scale Blu-Baby. Ahhh...memories... Too bad the Air Force canceled the contract. Darn politics!

Tony
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Old Jul 20, 2008, 11:44 PM
Geaux Saints
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Grafton, Il
Joined Nov 2007
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Tony
I found that pic and thought "Now there is the ultimate BB"
Someone tried to tell me it was one of those SC's but I knew better!
Mike

...and SOME people say the KFM only works at slow speeds if at all!
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Old Jul 21, 2008, 01:02 AM
BEC
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Auburn, Washington USA
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Yet another BB takes to the air.....

I finally finished the 32 inch KFm3/ailerons version I've mentioned awhile back and shortly after took it to a nearby Jr. High playfield and put the first 25 minutes of airtime on it.

First some stats:

Power is the same as my 33 UC version: Suppo B2208/12 on 2s through a Castle Creations Thunderbird-9. GWS 8x4 direct drive prop. Receiver is a Berg 4L and (at the moment) commands from a Multiplex Cockpit MM.

All up weight is exactly two ounces more than my UC airplane at 9.4 ounces plus battery. Most of the delta weight is in the wing as you'd expect, between the extra foam of the KFm layers and two TowerPro 5g servos and the required bits to make the ailerons waggle. I'm not sure why the second fuselage is 0.4 ounce heavier since the materials and equipment are all the same.

Initial balance was about 1/4 to 3/8 inch forward of the recommended place. More of this below.....

Flying impressions:

It was what they call "light and variable" winds today - shifting directions and speeds - at the school. I flew from moderate grass in a baseball outfield (and soon moved the gear to the forward slot - see pictures - to rake it forward and alleviate some nosing over).

It took to the air quickly, though not as fast as the UC - not surprising with the same power and almost 20% more weight. It was a little dicey at first because of a surprising characteristic: while the ailerons had PLENTY of roll authority the airplane really wants/needs some rudder to turn properly. It does not like "bank and yank" flying. And it's not because of a bunch of adverse yaw either. I set the ailerons up with some differential and rolls are amazingly axial for a high-winged airplane (another surprise).

I also had to fiddle with elevator trim at first (needed about four clicks of "up"). This I was almost able to do away with on the second flight after I taped a bit of weight to the back end of the airplane and got the balance point moved back to the recommended spot.

It is MUCH faster than the UC airplane and requires quite a bit more power for level flight. This led to 12-13 minute durations out the same batteries I routinely get 20 minutes from in the UC airplane (again with the same motor/prop/ESC combo).

Inverted was another surprise - only a hint of forward stick needed to keep the nose up. I think if I moved the balance point a touch further aft it would be neutral in pitch and would need no elevator for inverted at all.

Stalls were non events, but low speed flight coupled with a too-touchy rudder made for some interesting moments. More practice on my part required (and toning the rudder down a bit).

The downthrust amount seems to be just about right for a sport plane - there is only a little climb with added power - much less than the UC wing.

I do need to put in a bit of right thrust though (right now it has none). Keeping it straight in loops in particular was not easy and I tended to overcorrect (when I managed to move the rudder the correct direction). Again, more practice needed.

I have hopes of making better friends with it over the next little bit and then equipping it for floats (for the August Chilliwack meet). I also have a couple of HobbyCity motors to try either in this one or the 33 UC, including one of the infamous $5.95 ones, waiting for me at the post office.

Bottom line: It's amazing how different the two are with a "simple" change of wing. One more example of Tony's comment much earlier in this thread "Aircraft are holistic creatures, a sum of their parts and no stronger than the weakest link." I need to borrow that line for a couple of places where I'm teaching......

Added: there seems to be some limit on the length of an image "caption" - the bottom view should say: "A look at the bottom showing the on-the-surface implementation of the Willard/Stevens rubber-band-mounted gear, with two "slots" - one for hard surfaces, one for grass. You can also see one aileron servo, which is retained in the pocket with clear packing tape only (so far)."
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Old Jul 21, 2008, 07:36 AM
I'm not flying backwards!
Tony65x55's Avatar
Oshawa, Canada
Joined Sep 2004
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Congrats on the successful maiden and thanks for the great flight report. The collective experience mirrors yours too. I think you'll be amazed at how slow you can actually fly it when you start playing with trims, not as slow as the UC wing, but it will slow right down nonetheless.

I am consistently amazed with the roll qualities of this wing too. A little differential and it just spins around on its axis. You also made an observation I have noted too. The ailerons roll the plane, they don't turn it. This is, of course, how it should be and it lends credence to the design goal to create an aileron trainer with this wing. A newbie should learn to coordinate rudder and aileron. It isn't that the ailerons won't turn it, but it is visibly better with proper coordination. Good feedback for a new flyer.

I really like the Willard/Stevens landing gear and would like it if you could tell us more about its characteristics. My concerns are weight and the length of the gear legs. Tell me more when you can please.

You did a great job on this little plane and proved, once again, the holistic qualities of the BB. Thanks,

Tony
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Old Jul 21, 2008, 09:27 AM
BB repair shop
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Mobile, Alabama
Joined Apr 2008
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Laserman- the parts havn'e arrived yet but I am looking for them
Xanadu-I think I will reinforce the fuse like you especially where this one cracked.

One note on this BB, it was my first foamie ever and even during construction I learned where I could have done things better. I believe my next one will be even more stable. I believe I impressed some guys ,flying a store bought foam and plastic plane, with the ease at which I took to flyin. I would hand launch the BB myself and it would just zip out on a level flight until I was ready to start manuevering. I told them all about this forum and how helpful everyone was.
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Old Jul 21, 2008, 11:05 AM
In Rc for a LONG TIME FFAA#1
laserman's Avatar
Canada, ON, Ottawa
Joined Jun 2004
1,377 Posts
Quote:
Originally Posted by mobdan
Laserman- the parts havn'e arrived yet but I am looking for them
Xanadu-I think I will reinforce the fuse like you especially where this one cracked.

One note on this BB, it was my first foamie ever and even during construction I learned where I could have done things better. I believe my next one will be even more stable. I believe I impressed some guys ,flying a store bought foam and plastic plane, with the ease at which I took to flyin. I would hand launch the BB myself and it would just zip out on a level flight until I was ready to start manuevering. I told them all about this forum and how helpful everyone was.

have sent you a pm dan
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Old Jul 21, 2008, 11:40 AM
BEC
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Auburn, Washington USA
Joined Jan 2001
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Quote:
Originally Posted by Tony65x55
Congrats on the successful maiden and thanks for the great flight report. The collective experience mirrors yours too. I think you'll be amazed at how slow you can actually fly it when you start playing with trims, not as slow as the UC wing, but it will slow right down nonetheless.

I am consistently amazed with the roll qualities of this wing too. A little differential and it just spins around on its axis. You also made an observation I have noted too. The ailerons roll the plane, they don't turn it. This is, of course, how it should be and it lends credence to the design goal to create an aileron trainer with this wing. A newbie should learn to coordinate rudder and aileron. It isn't that the ailerons won't turn it, but it is visibly better with proper coordination. Good feedback for a new flyer.
Yeah - I was actually thinking about that while flying it yesterday....and wondering over a number of other "aileron trainers" I have flown over the years that really don't need you to use the rudder at all except for takeoff and landing. My two Sig Kadet variants (LT-25 and EP-42) come to mind - they like a touch of rudder but you can get by without it (at least at higher speeds), and my Mountain Models Dandy Sport and Switchback, both of which turn just fine with no rudder input at all until not far above stall speed. At low speeds, of course, the rudder is much appreciated on all of them....

Quote:
I really like the Willard/Stevens landing gear and would like it if you could tell us more about its characteristics. My concerns are weight and the length of the gear legs. Tell me more when you can please.
Some other detail pictures are earlier in the thread here . The gear is made from one piece of .078 wire about 12.5 inches long. It's retained by a couple of #16 rubber bands over another skewer in the monobloc. The "groove" assembly is a piece of dummy credit card and two or three chunks of Starbucks stir stick glued on the bottom. Not a huge weight hit and probably little more than the "stock" arrangement. The gear is resilient and handles rough surfaces well, is easily removed for straightening or transport, and you can control how easily a drag load flexes it fore and aft with rubber band tension.

I'll see if I can take a picture of just the gear showing some dimensions this evening. Note that my planes are both 2 inch monoblocs.

I call it "Willard/Stevens" because the first use of a one-piece rubber-banded on gear I ever saw was some of Ken Willard's designs going back to the early 1960s. Bill Stevens at Stevens Aeromodel in Colorado Spings has adopted the general idea and added the "slot" to keep it from sliding fore and aft on the fuselage bottom which really improves how it works (no more flipping it over - "retracting" the wheels - on a heavy landing). It first appeared on the SQuiRT 400 and is now used on all three SQuiRTs and the two (soon to be three) members of the SHAFT series as well.

Quote:
You did a great job on this little plane and proved, once again, the holistic qualities of the BB. Thanks,

Tony
Thanks for the designs!

I have another couple of newbie success stories for the 33 UC (one for mine, one for one that was built after seeing mine) that I'll post perhaps this evening.
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Old Jul 21, 2008, 03:31 PM
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Washington MO
Joined Jul 2008
567 Posts
My BB so far

I'm going to try to get some pics up soon but I got my Fuse mostly put together and my KFm sport wing is ready for final assembly tonight I am waiting on servos and radio to get here so I can start mounting those. Hoping to see them today or tomorrow. now I have a battery question. I am thinking that I am going to use This set up. but as this will be my first use of LiPo/Brushless. what would be a good pack/charger for this set up. or could someone explain some ot the numbering on the LiPo packs.
Thanks a bunch.
Jon
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Old Jul 21, 2008, 03:41 PM
Jack
USA, ME, Ellsworth
Joined May 2008
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Tony,

Thanks for sharing your genius with us. I'm getting started on building the BB 33 and also want to build the KFm3 sport wing for it too. My plan is to have a plane that I can use either wing on or maybe even to have two planes.

I have a question, is there a single sheet or full parts plan available for the "Blu Baby 32 inch KFm3 sport wing.pdf" file in the downloads area? I see you have them for the BB 33 and BB 24.

I had some trouble getting started on the BB 33 because I was having trouble making the cutting templates for the parts from the download with the tiled parts drawings. But Bill Seagraves and his ScaleAndTile3 applet got me off and running on the BB 33, I just had to tile the full drawing to get tiles that work with my printer. Now I'd like to do the same thing on the 32" KFm3 wing but the only drawing is the previously tiled nine page plan.

My issue is that the nine page KFm3 plans have a part of each page missing and don't join up when I print them so I'd like to tile them from a one page drawing like I did for the BB 33.

Thanks for your time,

Jack
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Old Jul 21, 2008, 03:45 PM
Geaux Saints
Hopalong X's Avatar
Grafton, Il
Joined Nov 2007
1,913 Posts
Quote:
Originally Posted by jhtitan
I'm going to try to get some pics up soon but I got my Fuse mostly put together and my KFm sport wing is ready for final assembly tonight I am waiting on servos and radio to get here so I can start mounting those. Hoping to see them today or tomorrow. now I have a battery question. I am thinking that I am going to use This set up. but as this will be my first use of LiPo/Brushless. what would be a good pack/charger for this set up. or could someone explain some ot the numbering on the LiPo packs.
Thanks a bunch.
Jon
I'm not putting off your questions but read the first post at the following link. It will give most of the basics and a great starting point for lipo batteries.
Making a copy for reference is a good idea also. I did last fall and still reference it occasionaly with all the crazy numbers. If you are like me you will forget most of it the first time.
This will give you some background info for ?? and to understand hopefully some of the answers you get.
Trying to help not be bossy.

http://www.rcgroups.com/forums/showthread.php?t=209187
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Old Jul 21, 2008, 06:31 PM
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60" EPP sport wing?

I am about to build this plane and I was wondering if anyone has built the 60" sport wing out of EPP? I have some 9mm and I was wondering if it would work or not.

Thanks,

Joe
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Old Jul 21, 2008, 06:40 PM
In Rc for a LONG TIME FFAA#1
laserman's Avatar
Canada, ON, Ottawa
Joined Jun 2004
1,377 Posts
Quote:
Originally Posted by Jmcdonald870
I am about to build this plane and I was wondering if anyone has built the 60" sport wing out of EPP? I have some 9mm and I was wondering if it would work or not.

Thanks,

Joe
Hmm epp you would definately need spars !! a very boucey wing that would be hehehe
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Old Jul 21, 2008, 06:50 PM
In Rc for a LONG TIME FFAA#1
laserman's Avatar
Canada, ON, Ottawa
Joined Jun 2004
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hmm the bb 24 edf did not survive the motors went boomies oh well, so on went a tp 2409-18 think that is enough power!! grunt grunt more power!! a binford more power bb 24
like this
http://www.hobbycity.com/hobbycity/s...3.8_Prop_Combo
laser
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Old Jul 21, 2008, 10:05 PM
I'm not flying backwards!
Tony65x55's Avatar
Oshawa, Canada
Joined Sep 2004
3,753 Posts
Quote:
Originally Posted by jackerbes
Tony,

Thanks for sharing your genius with us. I'm getting started on building the BB 33 and also want to build the KFm3 sport wing for it too. My plan is to have a plane that I can use either wing on or maybe even to have two planes.

I have a question, is there a single sheet or full parts plan available for the "Blu Baby 32 inch KFm3 sport wing.pdf" file in the downloads area? I see you have them for the BB 33 and BB 24.

I had some trouble getting started on the BB 33 because I was having trouble making the cutting templates for the parts from the download with the tiled parts drawings. But Bill Seagraves and his ScaleAndTile3 applet got me off and running on the BB 33, I just had to tile the full drawing to get tiles that work with my printer. Now I'd like to do the same thing on the 32" KFm3 wing but the only drawing is the previously tiled nine page plan.

My issue is that the nine page KFm3 plans have a part of each page missing and don't join up when I print them so I'd like to tile them from a one page drawing like I did for the BB 33.

Thanks for your time,

Jack
OK Jack, it is posted on page one.

Tony
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Old Jul 21, 2008, 11:06 PM
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Washington MO
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Thanks Hopalong. that was exactly what I was looking for. I figured someone had put it up somewhere just hadn't found it yet.
heres some pics of my progress so far. dont mind the mess small drafting table I use for everything. I think its coming along good so far let me know what you think.
Thanks
Jon
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Old Jul 22, 2008, 12:52 AM
BEC
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Auburn, Washington USA
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Been reading back pages of this thread.....and came across a discussion on dihedral:

Quote:
Originally Posted by springer
LarryR: I can't remember what real J3's look like for dihedral, but it's clear from the 150's, 152's at my local airport, on the ground they look like no dihedral, but in the air, they seem to have plenty. Cub might be the same, flex in wing produces dihedral once airborne. seems wierd, but it might be safer. I also recall being told about the flex in commercial airliner wings and remember watching it from a window seat in rough air - was a little disconcerting to see it flex but obviously designed to do that.
mike
If the wings on a Cub (or a 150/152) are flexing noticeably then I'd be worried about the lift struts.....alot!

I haven't been able to find a definitive J-3 three-view but the Taylorcraft A/B series (and related Austers) have 1 degree of dihedral, and since the Piper Cub is from the same designer I wouldn't be surprised if it, too, has a degree or so.

Now wing flex on an airliner, especially a big one - you bet - and that's by design.
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Old Jul 22, 2008, 01:50 AM
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Carmichael, CA
Joined Feb 2007
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all wings are designed to flex. big and small wings have similarly shaped aluminum structure, which is basically scaled up and down depending on size. for example, if you scale a j3 wing to fit a 747, the shape and thickness of the spars will be about the same with respect to span, so they go through roughly the same amount of strain. strain is an engineers way of saying "tip deflection per foot of wingspan".

that's why you'd notice the overall deflection more on a larger plane. same reason a 100 story skyscraper can get away with swaying 10' at the top and not break, while my single story house cannot.

hope this helps explain what you guys are observing out there.

kev
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Old Jul 22, 2008, 02:11 AM
BEC
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Well, sort of.....there is quite a bit more to it than that. Bear in mind that the spars in a J-3 or a Taylorcraft are spruce, not metal, and the wings are externally braced via the lift struts of which I spoke - which are steel tubes loaded in tension (when the plane is in positive-G flight).

Agreed even on a lightplane the wings flex some....but to say it just scales up to a 747 or 777 or now the 787 - when completely different materials (various aluminums on 747 or 777 and carbon fiber composites on 787 - all with different stress/strain curves) and load alleviation schemes are involved is rather oversimplifying things.

For one thing, any jetliner wing does not have a constant thickness to chord ratio in part to tailor the aeroelastics. They typically have a greater t/c at the root where the bending moments are higher (this reduces overall structural weight as well).

I'm sure one of our Structures guys (say Don Bailey who is d_gliderguy on here and a Boeing colleague of mine - who also writes for Sport RC Flyer) could explain it in much more detail. Or I could reach down to the Structures volume of the Roskam design books and start quoting, since they're stacked on the floor nearby - but it's better to talk Blu-Babies in this thread, I think.
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Old Jul 22, 2008, 02:17 AM
BEC
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More on the Willard/Stevens gear

Tony asked for more details on what I called the Willard/Stevens gear in this post yesterday. I linked to some other details in an earlier post of mine , but here is some more. The picture shows the dimensions of the gear I have on my BB 32 KF. It is formed in one piece from about 12 1/2 inches of 0.078 inch music wire.

As shown there's prop clearance for a 9 incher when using the 52mm GWS wheels I'm using. That means on moderate grass an 8 inch prop gets green tips, but the airplane gets up and down easily enough.

The gear weighs 0.6 ounces, evenly divided between the wire and the wheels.
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Old Jul 22, 2008, 06:46 AM
Geaux Saints
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Grafton, Il
Joined Nov 2007
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Quote:
Originally Posted by jhtitan
Thanks Hopalong. that was exactly what I was looking for. I figured someone had put it up somewhere just hadn't found it yet.
heres some pics of my progress so far. dont mind the mess small drafting table I use for everything. I think its coming along good so far let me know what you think.
Thanks
Jon
You start with a sheet of foam and out pops a BB!

Your welcome!
If your like me I read that lipo post about a dozen times before it soaked in.
You'll still have questions but some basics always helps.

Mike
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Old Jul 22, 2008, 07:03 AM
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Attica, MI
Joined Dec 2006
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BEC,

When I look at the WS gear, it looks like a no weight penalty for this configuration. In fact, I would say there is slightly less wire, and probably the same amount of wood with the exception of the additional dowel. That is likely offset by less glue required. Do you add any reifrcement on the side of the fuselage between the dowel and ply plate on the bottom?

As I remember, the Roaring 20's, Rascals, Schoolboys, etc... You had to wind up the rubber bands really tight to keep the gear from flexing too much. Otherwise the gear would flex on the landing and nose over anyway. Then again, I did not have elevator control to flair the landing either.

Ken
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Old Jul 22, 2008, 07:25 AM
Glue-it-again-Ben!
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Adelaide, Australia
Joined Apr 2008
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Quick question Tony or anyone else that can advise. My AP BB Kfm3 wing is coming along nicely. I'm up to gluing the second step from the smaller strip of balsa down to the wing surface. I'm thinking I might cut a 45 deg into the end that will glue to the wing surface to make a nice neat join. Will removing the 5mm step at this point and replacing it with a smooth transition from the second step to wing have any detrimental effects on the wings performance?

Cheers for any help!

Ben

(Also posted on KF thread)
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Old Jul 22, 2008, 07:34 AM
I'm not flying backwards!
Tony65x55's Avatar
Oshawa, Canada
Joined Sep 2004
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Quote:
Originally Posted by blxpy
Quick question Tony or anyone else that can advise. My AP BB Kfm3 wing is coming along nicely. I'm up to gluing the second step from the smaller strip of balsa down to the wing surface. I'm thinking I might cut a 45 deg into the end that will glue to the wing surface to make a nice neat join. Will removing the 5mm step at this point and replacing it with a smooth transition from the second step to wing have any detrimental effects on the wings performance?

Cheers for any help!

Ben

(Also posted on KF thread)
Yes! The steps are what give the wing its performance. Build to the plan and you will be happy...honest.

Tony
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Old Jul 22, 2008, 07:47 AM
I'm not flying backwards!
Tony65x55's Avatar
Oshawa, Canada
Joined Sep 2004
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Quote:
Originally Posted by dz1sfb
BEC,

When I look at the WS gear, it looks like a no weight penalty for this configuration. In fact, I would say there is slightly less wire, and probably the same amount of wood with the exception of the additional dowel. That is likely offset by less glue required. Do you add any reifrcement on the side of the fuselage between the dowel and ply plate on the bottom?

As I remember, the Roaring 20's, Rascals, Schoolboys, etc... You had to wind up the rubber bands really tight to keep the gear from flexing too much. Otherwise the gear would flex on the landing and nose over anyway. Then again, I did not have elevator control to flair the landing either.

Ken
I totally agree. If there is any weight penalty, which I doubt, it is minimal. Nice system. It would go very well on the larger BBs especially. The camera planes can be rough on landing gear fully loaded.

Tony
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Old Jul 22, 2008, 08:14 AM
Glue-it-again-Ben!
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Adelaide, Australia
Joined Apr 2008
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Quote:
Originally Posted by Tony65x55
Yes! The steps are what give the wing its performance. Build to the plan and you will be happy...honest.

Tony
Thanks for the speedy reply Tony. Glad I asked before buggering it up!

Very happy with how the wing is coming together. I love the way the LE is formed - looks nice and strong and should put up with a few knocks.

I had to shape the top step a bit before bending it down to the spar so that I didn't end up with a symmetrical airfoil. Doing that, I managed to keep the bottom surface perfectly flat. LE is probably a little more 'blunt' than on the diagram - can always squish it down a bit I guess. Will post a pic of the profile when it's done to get your opinion.
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Old Jul 22, 2008, 09:02 AM
I'm not flying backwards!
Tony65x55's Avatar
Oshawa, Canada
Joined Sep 2004
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Quote:
Originally Posted by blxpy
Thanks for the speedy reply Tony. Glad I asked before buggering it up!

Very happy with how the wing is coming together. I love the way the LE is formed - looks nice and strong and should put up with a few knocks.

I had to shape the top step a bit before bending it down to the spar so that I didn't end up with a symmetrical airfoil. Doing that, I managed to keep the bottom surface perfectly flat. LE is probably a little more 'blunt' than on the diagram - can always squish it down a bit I guess. Will post a pic of the profile when it's done to get your opinion.
Sounds fine. Blunt is ok and I usually bend the top surface somewhat to camber it..

Tony
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Old Jul 22, 2008, 09:08 AM
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Joined Apr 2007
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I was wondering. Why not use the fold already in the fff for the leading edge of a kfm wing instead of folding the flat foam over itself? Is there some important point I'm missing?
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Old Jul 22, 2008, 09:22 AM
I'm not flying backwards!
Tony65x55's Avatar
Oshawa, Canada
Joined Sep 2004
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You can use the existing fold. However, I find that doing it in two pieces with tape makes for a smoother, prettier leading edge.

Tony
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Old Jul 22, 2008, 09:44 AM
Jack
USA, ME, Ellsworth
Joined May 2008
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Thanks for the quick reaction on the BB 33 KFm3 single sheet plan Tony, it is just what I needed.

"..Very happy with how the wing is coming together. I love the way the LE is formed - looks nice and strong and should put up with a few knocks..."

I was playing with some blueboard scraps and did that thing as shown in the KFm Wing Fold Instructions.pdf at this link:

http://www.rcgroups.com/forums/showp...&postcount=140

That shows how to tape the lower wing sheet and KFm sheet together at a 90 degree angle with packaging tape and then bend the vertical sheet down to form the airfoil. It compresses the foam at the leading edge and forms an incredibly nicely shaped leading edge.

As you bend the vertical top piece closer to laying flat on the lower wing sheet, if you have it in hand, it does want to bend the lower surface also and the two form a symmetrical airfoil that would excite the eye and mind of any modeler who has ever built a wing.

There is a inclination to want to improve the shape of the airfoil and make it more symmetrical but, like Tony says, it is not what works the best.

I have another document that I downloaded, the "Kline-Fogleman Airfoil Comparison Study 2-1.pdf", that bears out Tony's recommendations and really helps me see difference in the looks and performance of the different air foils being used in the various BB designs. It has beautiful images of the airfoils as tested and also lots of number for us to study and agonize over. That study is here, along with some brilliant discussion from The Genius Himself (aka Tony):

http://www.rcgroups.com/forums/showp...38&postcount=1

So when I build the KFm3 wing, I'm going to try to keep the sheet that is the bottom wing surface as flat as possible when I bend the top back. It looks like if you sort of force the top strip back towards the leading edge that will keep the bottom sheet laying flat as you get it all glued together.

Jack
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Old Jul 22, 2008, 10:35 AM
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Quote:
Originally Posted by jackerbes
......
I was playing with some blueboard scraps and did that thing as shown in the KFm Wing Fold Instructions.pdf at this link:

http://www.rcgroups.com/forums/report.php?p=7448731

...........

Jack
Jack your link above takes you to a page to report bad post not to the wing fold instructions.

RC
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Old Jul 22, 2008, 11:12 AM
Jack
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"..Jack your link above takes you to a page to report bad post not to the wing fold instructions..."

Ooops! Thanks for the catch on that. I've edited the post, the links are right and now take you to the posts that contain the documents. I think I messed it up by trying to post a link direct to the download. So now you can also see the discussion that was going on at the time now.

Jack
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Old Jul 22, 2008, 11:42 AM
Jack
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Joined May 2008
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The Arguably Perfect Blueboard Cutting Knife

I've been reading this entire thread again, a little at a time, and snipping and noting gems of info.

I just cut out my first BB, a 33, and was unhappy about some of the problems I was having using various utility and Exacto knives and blades to cut some of the long straight cuts. The problem I was having was that of the paper layer and/or the foam wadding up and getting dragged along with the tip of the knife and that producing a torn and jagged edge on the bottom surface.

I was in Lowes yesterday and saw an inexpensive plastic utility knife that has 13 snap off segments that will give you a new point and cutting edge in a matter of seconds. Also the long thin blade and adjustable extension of the blade seemed like they would be useful. So for about $2.00 I decided to give it a try.

Wow! It worked great! The thin blade and variable extension worked perfect for the various thicknesses of foam, it worked good on multiple layers, also cut beautiful bevels when used at an angle and following a straightedge.

And I could also shave off very thin layers along an edge to clean up edges or trim them for better fits in places like where the wing bevels mate.

And today I notice that in Tony's tutorial for rolling the UC wings, he has the *same* knife laying on his countertop! Can there be any higher endorsement for a tool?

It is small, light, easy in the hand, and is marked "American Lite". The blades are replaceable and cheap too. We'll have all of Tony's secrets if we pay attention and keep him talking. :>)

Jack
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Old Jul 22, 2008, 12:32 PM
I'm not flying backwards!
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Pssst...want another secret... you can buy those knives and their blades at almost any dollar store. Ten blades for a buck. And that little slot in the cap of the knife is for breaking off the old blade tips to freshen the blade.

Geez, when I saw your post I thought I was going to learn something new and cool.

Tony
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Old Jul 22, 2008, 12:42 PM
BEC
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Quote:
Originally Posted by dz1sfb
BEC,

When I look at the WS gear, it looks like a no weight penalty for this configuration. In fact, I would say there is slightly less wire, and probably the same amount of wood with the exception of the additional dowel. That is likely offset by less glue required. Do you add any reifrcement on the side of the fuselage between the dowel and ply plate on the bottom?
I haven't yet. Of course the dowel/skewer goes through the monoblock and should be well glued to it (PU glue is probably ideal). I can imagine in the AP birds that have gross weights rather higher than the 12 ounces of the 32KF you might want to do that. In the Stevens airplanes there is a doubler inside the fuselage for that dowel penetration.

Quote:
As I remember, the Roaring 20's, Rascals, Schoolboys, etc... You had to wind up the rubber bands really tight to keep the gear from flexing too much. Otherwise the gear would flex on the landing and nose over anyway. Then again, I did not have elevator control to flair the landing either.

Ken
Right - built three Schoolboys and a Showmaster myself. That's where Bill Stevens' tiny but hugely significant addition to the idea comes into play. The slot that keeps gear from sliding fore and aft on the bottom of the fuse prevents the gear from sliding then collapsing on a heavy landing. The rubber band tension need not be quite so great as a result.

And as you can see in my BB 32KF post, I arranged two "slots". When the gear is in the forward slot it is raked forward which helps in the grass. On a harder surface the forward placement would be ground-loop happy but for a harder surface the gear can be in the aft position which is better suited to that application.

BTW, Tony, the gear works on any size plane - the SA Lil' SQuiRT weighs less than 3 ounces and benefits from this arrangement. I'll be doing my BB 24 UC this way as well. But it also works on the SQuiRT 700 and SHAFT 25e which are both pretty large models.
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Old Jul 22, 2008, 01:00 PM
BEC
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BB 32 KF - additional thoughts

Two things that have popped into my head about the sport wing/KFm3 wing BB32....

First - I just read the discussion about forming the LE of the KFm3....I think I should've cambered the top piece a bit. My wing has quite a bit of "Phillips entry". The airfoil is far from symmetrical, but the lower surface is nowhere nearly as flat all the way to the LE as it is drawn on the plan. Hmmmmm.....

Second - I wound up with 0.2 ounces of lead in the tail to get it to balance in the right place (with a 1 ounce motor). I noticed that the center of the battery compartment in the monobloc is well forward of the balance point for the KFm3 wing so putting a battery in shifts the balance point forward. Perhaps the sport wing version needs a different monobloc design that extends further aft and moves the battery back so that it's centered under the balance point as with the UC variant? I actually did extend mine back a bit but not enough as it turns out. Just a thought.
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Old Jul 22, 2008, 02:44 PM
Jack
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Joined May 2008
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BEC,

That is pretty interesting stuff isn't it.

In the image of the KF profile cross sections with the study (the second link) I like the looks of the KFm3 9-12% the best.

It looks like if you used balsa of 1/8" x 1/4" and 1/8" x 1/2'" for the front and back step supports and a spruce spar that was 1/8" x 3/4" to make the tall center spar it would give you a very nice wing.

Locating the steps right would give you something that would push the foam forward a little to form that camber seen from the leading edge to the tall support and it would also give you a good spar for stiffening the wing.

Jack
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Old Jul 22, 2008, 06:11 PM
In Rc for a LONG TIME FFAA#1
laserman's Avatar
Canada, ON, Ottawa
Joined Jun 2004
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well got some goodies on order from hobby city!!! ordered a battery monitor for 2s-6s batterys and a 18 amp esc for a new bb if i cna get the wife to not see the build of a new plane!!!
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Old Jul 22, 2008, 06:44 PM
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Grafton, Il
Joined Nov 2007
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Laserman!!! Bring toys!

You can come over to my house and build.
My wife won't mind.

Got my 2S-800mah today for 10gm 24"BB.
3 for $24 couldn't resist. And they will work in my SE5a build.

Laser you can come build and teach me how to crash properly- I mean fly properly.
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Old Jul 22, 2008, 07:06 PM
In Rc for a LONG TIME FFAA#1
laserman's Avatar
Canada, ON, Ottawa
Joined Jun 2004
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Quote:
Originally Posted by Hopalong X
You can come over to my house and build.
My wife won't mind.

Got my 2S-800mah today for 10gm 24"BB.
3 for $24 couldn't resist. And they will work in my SE5a build.

Laser you can come build and teach me how to crash properly- I mean fly properly.
well whats the job market there like!!! i am currently un employed used to work for dell doing tech support! hehee you don't crash err fly you have to use small touches to the stick to keep it in the air!! lol, that is a idea a se5a hmm or something else if tonys got a small single engine plan or even better a piranha!!! hmm a fish!!!!! hehehe
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Old Jul 22, 2008, 07:25 PM
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Grafton, Il
Joined Nov 2007
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Ford closed their plant last year. Chrysler is cutting their work force in half at the minivan line and it appears the truck line may shut down completely. Chevy is cutting back heavy.

Tech jobs I have no idea.
The auto plants are major employers but are a lot smaller overall impact on the economy than they were in decades past.
St. Louis area seems to be above average economy wise so far.
You can check monster.com and such.
The link below is a local job search. Might be worth a look.

http://regionalhelpwanted.com/p/254/...ols.htm?SN=254
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Old Jul 22, 2008, 07:36 PM
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Grafton, Il
Joined Nov 2007
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Quote:
Originally Posted by Tony65x55
And that little slot in the cap of the knife is for breaking off the old blade tips to freshen the blade.Tony
Well I'll be a monkeys Uncle.
I've been cursing those blades every time I need to break them off.
Pliers work- sometimes a clean snap mostly not.

Now I know how to use my $ store "SuperTony Knife".
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Old Jul 22, 2008, 08:42 PM
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Washington MO
Joined Jul 2008
567 Posts
silly question

so I got my radio and servos today and I was wondering(as I was mounting the servos and rx) where do you put the Ant wire? lol I didn't see an Ant tube in the build plans lol and that's the only place I know to put them. I thougt I would just run it all the way to the tail and stick a little out the back but I'm wishing I would have had that idea before I mounted the servos.
Thanks
Jon

and yes the job market in the St.L is kinda sucking ATM but there are a few nice Temp agencies where you can get on with some of the bigger firms in tech areas. I work for one while I am trying to get my repair business up and going strong.
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Old Jul 22, 2008, 08:52 PM
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laserman's Avatar
Canada, ON, Ottawa
Joined Jun 2004
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Quote:
Originally Posted by jhtitan
so I got my radio and servos today and I was wondering(as I was mounting the servos and rx) where do you put the Ant wire? lol I didn't see an Ant tube in the build plans lol and that's the only place I know to put them. I thougt I would just run it all the way to the tail and stick a little out the back but I'm wishing I would have had that idea before I mounted the servos.
Thanks
Jon

and yes the job market in the St.L is kinda sucking ATM but there are a few nice Temp agencies where you can get on with some of the bigger firms in tech areas. I work for one while I am trying to get my repair business up and going strong.
yuppers just let it hang out tape it to either the vertical stab or the horizontal stab and let the rest float

well i am in canada i don't think they would like me there i would want free healthcare and such!!! LOLOL
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Old Jul 23, 2008, 11:22 AM
AKA Don
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There is no such thing as "free" healthcare (or lunch)!
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Old Jul 23, 2008, 11:32 AM
AKA Don
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United States, MI, Houghton Lake
Joined Dec 2002
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[QUOTE=jhtitan]so I got my radio and servos today and I was wondering(as I was mounting the servos and rx) where do you put the Ant wire? lol I didn't see an Ant tube in the build plans lol and that's the only place I know to put them. I thougt I would just run it all the way to the tail and stick a little out the back but I'm wishing I would have had that idea before I mounted the servos.
Thanks
Jon

...QUOTE]

To "fish" the antenna wire down a crowded fuse' just insert a piece of sharpened control rod wire from the tail. plunge through formers and wiggle and jiggle (or back up and try again) until you get past the servos. then tape the tip og the antenna to the end of the wire and pull the antenna through. It's normally not a bad job. If all else fail you can run it outside the fuse, but I like to keep it in. I even let it double back inside the fuse' so only a 1/2 to 1" loop sticks out the back. A wire dangling out the back always looks goofy to me. I know folding it back reduces the range, but the way I fly I have never had a plane get out of range. I guess my eyes are just not that good.
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Old Jul 23, 2008, 04:03 PM
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Renton, WA
Joined Oct 2005
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Please recommend a cheap power system from Hobby City http://www.hobbycity.com/hobbycity/store/uh_index.asp (brushless or brushed motor, esc, prop, lo-poly or perhaps cheaper nimh batteries) and charging system for Baby Blue 33 and 40 inch wing span trainer.
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Old Jul 23, 2008, 05:20 PM
Jack
USA, ME, Ellsworth
Joined May 2008
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A motor Hobby City used to sell as the Blue Wonder was a popular choice in the past. They no longer sell that same motor under that name but if you go back over the descriptions of recent builds and maiden flights, you can get a good feel for the Hobby City motors that people are using.

Builders often just refer to the Hobby City part number or a partial part number for the motor. Like calling them the "28-22" or "28-26" when they are the HXT 28-22-azj and HXT 28-26-azj. Those, by the way, are good candidates for powering the BB 33 I think and maybe the 40 too. Or is it a 42? I don't think I remember a BB 40.

Drive line choice varies quite a bit as there is no real hard and fast specification for the motor and different builders want more or less power, bigger or smaller batteries, and are using different styles (UC, KFm) and sizes (32, 33, 42) of wings.

The Blu-Baby really personifies the "ubiquitous". It has been the subject of so much experimentation and variation as far as size, design, and uses that it defies simple descriptions.

I'm working on a BB 33 and ordered this motor for it:

http://www.hobbycity.com/hobbycity/s...idProduct=5208

I already have a pair of 7.4V Lipo batteries that I can use with the BB 33 so I ordered a motor with a little higher (1700) Kv rating to use with those batteries. If I had, and was going to use, a higher voltage 11.1V Lipo pack, I probably would have bought a motor with a 1300 or 1400 Kv rating.

With the plane built, motor mounted, and a prop selected, I'll be able to see what I have as far as power and endurance. And if I've missed the mark on my choice and where and in what direction. In fact, now that I've said it aloud here, I'll probably find out now. :>)

Jack
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Old Jul 23, 2008, 05:32 PM
In Rc for a LONG TIME FFAA#1
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Canada, ON, Ottawa
Joined Jun 2004
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Quote:
Originally Posted by bz1mcr
There is no such thing as "free" healthcare (or lunch)!
well when i go to see my doctor ie for my diabetes i just get off the bus and walk in, and when done walk out no stopping in to pay for any thing unless i have to get some meds! , any ways looks like i will start work on a piranaha hehehe, and call it the bb eater!! hehehe
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Old Jul 23, 2008, 05:43 PM
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Laserman,

Bet it won't keep up with Mach-BB!

Mike
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Old Jul 23, 2008, 05:50 PM
AKA Don
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United States, MI, Houghton Lake
Joined Dec 2002
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Quote:
Originally Posted by jackerbes
A motor Hobby City used to sell as the Blue Wonder was a popular choice in the past. They no longer sell that ...
I'm working on a BB 33 and ordered this motor for it:

http://www.hobbycity.com/hobbycity/s...idProduct=5208

...Jack
I believe that is the motor known as the blue wonder. I think it was first just available as a 1300 Kv motor and then the 1700 (same color) and 3000 Kv (with silver in place of blue) became available. Some of the 3000 motors were made with blue cans, and maybe even some of the other motor winding were sometimes made in the silver cans. So can color is not a reliable way to tell the different windings (Kv's) apart.

I agree pretty much any motor with a weight of 18-35g and a Kv of 1000-2000 will work well on the BB's if the battery and prop are matched to the motor.
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