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Old Mar 08, 2010, 03:58 PM
Always Ready!
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Chicago, IL
Joined Dec 2006
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Build Log
Big Pink Beaver

64" RC DeHavilland Beaver DHC-2 : electric foamie (5 min 36 sec)


*updated 6.10.2010* -- finished pics are here and here.

Here is my scratch-built 64" wingspan (1/9 scale) DeHavilland Beaver built primarily from "pink" 1/2" and 1/4" insulation foam. A little bit of lite-ply for the firewall, bamboo skewers and popsicle sticks here and there for struts and reinforcements ... overall a cheap and simple "scale" bird that someone with moderate foam-building skills can build in a couple of weekends.



The fuselage is simple slab-sides, which lends itself easily to building from the thicker 1/2" pink foam. Once the "box" fuselage is glued together, you can sand the edges round for better scale appearance. Empennage likewise is from 1/2" pink... shaved and sanded for round leading edge and tapered trailing edge.

The entire cockpit is removable to act as the battery hatch -- the front of it slides under the cowl and the top fastens with magnets.

The wing is built-up from 1/4" FFF ribs and skin with a 3/16" CF arrowshaft spar... common foamie practice... ribs about every 4". Wingtips are sanded from solid foam... I glued 2-pieces of the 1/2" pink foam together then sanded them to shape. 2-piece wings are removable... held on with a clip and a pin, plus the wing struts keep them in place.

I covered the plane with printed paper. The ink is sealed with Krylon Clear Acrylic, with UV protection. Then I cover the paper with "crystal clear" packing tape. The paper skin is then glued to the foam like a giant sticker using 3M Super 77 spray adhesive. Have to be very precise with the alignment to get it placed straight. This is the hardest part of the build. There are lots of other options... you could do glass/epoxy, or tissue/WBPU, then spray-paint it. Or, you could use a low-temp plastic covering like Econokote. I think you could even use self-adhesive shelf-liner from Home Depot, etc (they have "stainless steel" shelf-liner - might be interesting). Colored packing tape? Sure. Or just leave it pink!

Power is from a cheap HobbyKing DT-750 motor with 11x7 2-blade or 11x6 3-blade prop... makes over 40oz of thrust on 3S, using just a 25A ESC. This motor is easy to rewind for more power if I need it -- stock wind is dLRK 18T, but 15T-16T using 21AWG wire is possible. Currently I am flying the plane on wheels, but I plan to put floats on it soon, so I might need the extra power for the extra drag and weight. For batteries I have "Y-paralleled" two(2x) 2200mah 3S Lipos --- mostly because I need the nose-weight for balance. You don't need a very high C-rating... the DT750 only draws about 12amps at cruise speed, which is only 6amps per battery since they are in parallel. With this setup I can fly casually for over 30 minutes. 40 minutes is possible if you are very light on the throttle.

The plane uses six 9-gram HXT900 servos... 2 for ailerons, 2 for flaps, 1 each for rudder and elevator. They seem to be holding up very well... this is a slow-flier with a light wing-loading so there isn't much stress on them. You might use a 12-gram on elevator for peace-of-mind, but so far I've had no problems.

She's a real sweet flier -- very scale-like -- a relaxing plane to fly. I have made my plans available for free... so hopefully there are few readers who are encouraged to build one. One caveat: The "Misty Fjords" paint scheme is copyrighted and I asked permission to use it. Please do the same, or use a different paint scheme.

Enjoy.

*updated 7.15.2010* -- PLDawg maidened his Beaver. Congratulations!
DeHavilland Beaver Maiden.WMV (3 min 58 sec)


*updated 4.17.2011* -- ComputerDag maidened his Beaver. Awesome! Flight 2
Pink Beaver maiden flight (2 min 34 sec)


LeLeopard's "Medium Beaver"
DHC2 beaver RC.wmv (3 min 34 sec)


ChinaClipper's "Micro Beaver" which were built using scaled down plans
Micro Big Pink Beaver with Floats (1 min 37 sec)


ChinaClipper's full-scale -- crashed when a strut came loose and the wing nearly folded! Not bad though for being +2lbs overweight.
My model DHC-2 Beaver First Flight! (3 min 41 sec)


Igor Čiča maidened his beautiful-looking Beaver -- awesome flight!
RC Big Pink Beaver by Igor Čiča (5 min 22 sec)


Igor's second Beaver:
RC BEAVER-2 by Igor Čiča (5 min 31 sec)


Paul from the Netherlands maidened his 80% version -- a beautifully finished model.
Paul_Beaver_150413b (9 min 4 sec)


Trein from the Netherlands maidened his 44oz Beaver... it really floats on air.
Mijn film (3 min 28 sec)
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Last edited by warhead_71; Jul 22, 2013 at 09:05 AM.
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Old Mar 08, 2010, 04:20 PM
John 3:16
Daddy-O's Avatar
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Joined May 2003
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Looks great Warhead. I'm looking forward to watching your progress with this one.
Daddy-O
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Old Mar 11, 2010, 11:06 AM
'Cobra Fan - P-39 & P-63
Rengine's Avatar
Fort Collins, CO
Joined Aug 2004
323 Posts
Warhead...

Great build idea...i've seen a few big pink beavers but THIS one takes the...uh...cake. I bet you can't wait to get that beaver wet...floats are cool!
I could go on...but i'll let others join the fun too!

subscribed!
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Old Mar 11, 2010, 11:13 AM
Always Ready!
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Chicago, IL
Joined Dec 2006
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Yes - I'm really looking forward to getting my Big Pink Beaver wet.

I have been reworking the battery hatch area... I just about have it figured out. I leave for vacation next Tuesday for a week, but when I get back I might get started on this.
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Old Mar 11, 2010, 06:48 PM
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Chicago, IL
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I just printed this out... wow it's big. I might go ahead and cut out the fuselage parts and get started on it this weekend. I think with the foam construction it should be pretty light... I have a couple of 3200mah Lipos that should fit just fine... or I might parallel a couple of 2200mah Lipos together and get more weight up in the nose for balance. Still should be no problem for the DT750... at least on wheels. On floats it might need more oomph. Time will tell.
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Old Mar 11, 2010, 06:50 PM
Up-Out-&-Gone
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Charelston SC U.S.A.
Joined Mar 2007
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Excellent choice Warhead_71! this is a great build in the making!
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Old Mar 26, 2010, 09:25 AM
Always Ready!
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Chicago, IL
Joined Dec 2006
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Back from vacation...

I have the fuselage together and it looks pretty good. The windscreen I will build up with balsa so I can put some clear plastic windows in there for scale looks. I've started to cut the wing ribs and should be able to slap the wings together in one evening. I'll try to get some pics posted tonight.

*edit* -- I decided to build the windscreen just as a "wrap"... much quicker and weighs a lot less. I could cut out the windows and make clear panes from transparency film... but why? Looks good as is.
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Old Mar 26, 2010, 01:54 PM
Scratch building addict
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United States, CA, Felton
Joined Jan 2005
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I just want to post something on a thread with this title. There, I did it.

Actually that's a really nice design, and I love the way beavers fly, so stable and graceful, think I'll scale this one down and use wheels.

Where are u getting this pink foam? I can't find it anywhere in cal.
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Old Mar 26, 2010, 02:21 PM
Storm Runner guy
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USA, OK, Muskogee
Joined Nov 2008
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Quote:
I love the way beavers fly
Sorry, just had to quote it
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Old Mar 26, 2010, 02:49 PM
Always Ready!
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Chicago, IL
Joined Dec 2006
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The foam is available at Home Depot or Lowe's -- and most other building supply stores.

The 1/2" foam comes in 4'x8' sheets. You can get other thicknesses: 3/4", 1", 1.5", 2", etc. Also comes in blue... depends on the manufacturer.

The 1/4" is fan-fold-foam (FFF) 2'x4'x50sheets, (also blue or green in some stores). You can also buy individual Depron sheets or sheets of foam-core board and soak the paper off.

I just happen to have pink locally, and it makes a catchy title, but it could as easily be called a Big Blue Beaver if I shopped at a different store
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Old Mar 26, 2010, 02:55 PM
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United States, CA, Felton
Joined Jan 2005
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I couldnt find it at HD in california, all they had was HUGE 10'x15' or so sheets of the white stuff. That's literally all they had foam wise ! But I'll try Lowes, thanks.

I can't even find small sheets of plain old 1 or 2 inch white stuff anymore. Had one hardware guy say they're gonna stop selling it...environmental issues. Hope he's wrong.

Youre right, pink beavers are better. (couldnt resist).
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Old Mar 26, 2010, 03:15 PM
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Maybe try other building supply stores, or roofing and construction contractors, etc. -- they might give you scrap for free. The big box stores might stop selling it to be PC, but I'm sure it's still being used for insulation... just need to make some phone calls. Might even try a surf shop, etc... those boards are made from foam too.
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Old Mar 28, 2010, 08:19 PM
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Here it is so far. I did some rough whittling to the edges to save on sandpaper... I will round the edges of the box fuselage, and taper the trailing edges of all the control surfaces. A razor box-cutter makes quick work of it.
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Old Apr 13, 2010, 10:43 PM
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Got just a little further on the Beaver... One wing is done and the other is on the build table. Also sanded the edges down smooth and made a nice paper template for the canopy. Sure is a PITA to get that pointy window just right.

I weighed all the parts and the empty airframe comes in at 12oz. Paper covering will add about 2oz, and electronics another 10oz (guesstimate)... landing gear will be about 4oz for fat bush wheels or 8oz for floats... so an AUW of 28oz for land or 32oz for water.

30" span by 6.5" chord per wing x2 gives me 390sqin. That's a wing loading of 10-12oz/sqft.... should be a real floater.

.
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Old Apr 13, 2010, 10:59 PM
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USA, CA, San Carlos
Joined Nov 2007
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one of the most dirty threads i've seen on RCG so far...even worse would be the "big brown beaver," yuck!

recently i've noticed alot of "giant" foamies popping up in the scratchbuilt forum - i like it!

- Jeff
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