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Oct 10, 2015, 05:54 PM
Balsa&Tissue
payne9999's Avatar
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Build Log

YAK Attack-Yak 55 Scratch build - 60cc


I found a really well designed Yak 55M on line and the fellow is offering all the DXF files, instructions and reference photos as basically open source (free).

Like I said it is a beautiful design, great execution and designed as nice as some of the top ARF's.

I like the style (bubble canopy) of the 55 and the really long tail moment (good ground handling). I am not so much a 3D guy but a scale builder but I have always liked the Russian aerobatic planes.

Instructions are in Russian but the pictures are good enough and with a smart phone and Google translate you can point the camera on your phone at the instructions and it instantly translates it on screen! Dang, I work in hi-tech and that is amazing.

Wingspan: 85"
Exact scale: 1/3.7 ~27%
engine size 50-60cc gasoline
Finish: Balsa sheeted with either glass and paint or traditional shrink wrap.
Construction: 3mm baltic ply, 2mm balsa and 3mm balsa. Aluminum wing rod, basswood stringers and spars.
Features: removable wings (of course), removable horizontal stabs. interlocking self-jigging parts, requires no large plan sheets to build. Goes together like a 3D puzzle. A fast build design style similar to commercial ARF's where they try to keep labor to a minimum.

The plane is almost entirely sheeted so I will go ahead and sheet all areas and finish in light glass cloth, primer and paint.

The fuse went together (minus sheeting) in just a few hours.

Dave
Last edited by payne9999; Oct 10, 2015 at 06:16 PM.
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Oct 10, 2015, 05:59 PM
Balsa&Tissue
payne9999's Avatar
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Here are the Instructions


Instructions attached so you can see how nice the design work is!

Design work by: Vlasov Evgeny of Russia.

You know what they say: Once you go YAK you never go back.

Files located here on grabcad:
https://grabcad.com/library/yak-55m-...model-aircraft

Dave
Oct 10, 2015, 06:05 PM
Balsa&Tissue
payne9999's Avatar
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Some screen shots of the CAD design.
Oct 10, 2015, 08:35 PM
Balsa&Tissue
payne9999's Avatar
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Fuse assembly continuing on:

60cc motor will have on-board electric start from Mile High RC. The 1500 3s Lipo is for the starter motor. Choke and auto start will be activated from the transmitter.

Dave
Oct 12, 2015, 05:27 PM
Balsa&Tissue
payne9999's Avatar
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Last night I finished the canopy framing, fuel and oil tank installation, smoke pump and smoke shut off valve. Tested all the servo functions and all is working well.

The way this model is designed it goes together easy and fast. The canopy was a dead on fit. the overall accuracy of the CAD work is spot on.

Dave
Oct 14, 2015, 10:50 PM
Balsa&Tissue
payne9999's Avatar
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Fuselage now has balsa sides sheeted as well as the turtle deck. Bottom covered in fabric and primed, fuse sides, turtle deck and canopy base all glassed with 2.5 ounce.
Oct 17, 2015, 01:39 PM
Balsa&Tissue
payne9999's Avatar
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Fuse, rudder and fin glassed and the h-stab framework is done. Need to make a mold for the cowling.
Oct 18, 2015, 06:19 AM
Balsa&Tissue
payne9999's Avatar
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Tail group is coming along. As soon as the tail is complete and glassed I will be testing the engine to make sure after it has been sitting around for months it will still work. Also, started piecing the wing together.

Put in a mock instrument panel today. I want to find a place to put the tachometer so I can see it during run-up but it might look bad in the cockpit since it is fairly large. Maybe magnetic hatch will do the trick.

I have decided on a color scheme. There are so many Yaks and other 3d-ish planes out there and they all sort of look the same to me, I wanted something completely different. Since I like military aircraft colors and patterns I am going with this one.

I could only find 2 pictures of this one and no background info. If someone knows about the history of this one or where there are more pictures I would welcome the help. In the mean time I will keep searching.

Dave
Oct 21, 2015, 10:41 PM
Balsa&Tissue
payne9999's Avatar
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Ready for wing sheeting and primer on the elevators.

It looks like I will have less than $200 in the airframe (not counting any electronics or engine). When I look at similar ARF AIrframes that are 50cc YAK-55's I see $800 to $1350 plus shipping.

This is an easy build but I still have to build a glass cowl and wheel pants but for a savings of $600 and up Ill take on the work.

Dave
Oct 28, 2015, 07:41 PM
Registered User
There is an edge and mx-2 of the same designer have not found yet?
I would cut a kit but here in my country do not get light ply
Oct 28, 2015, 09:12 PM
Registered User
Nergall's Avatar
Do these designs build light enough for a good 3D airplane?
Oct 29, 2015, 11:03 AM
Balsa&Tissue
payne9999's Avatar
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Quote:
Originally Posted by Nergall
Do these designs build light enough for a good 3D airplane?
Mine is almost done, I will weigh it tonight but it seems plenty light for such a large plane.

I used standard baltic or Russian birch 1/8 ply in mine. You may not need light ply.

Dave
Oct 29, 2015, 04:26 PM
Balsa&Tissue
payne9999's Avatar
Thread OP
Almost ready for final assembly. As soon as it is together and has a proper prop it will be time for a maiden (in primer). I am thinking of a 24X8 or 24X10 for the 60cc motor.

I am not a 3D person but just standard aerobatics. Do those prop sizes sound OK?

Thanks,

Dave
Oct 29, 2015, 07:50 PM
Registered User
very good scale not seen because there is nothing to reference.
Oct 30, 2015, 12:00 PM
Balsa&Tissue
payne9999's Avatar
Thread OP
Quote:
Originally Posted by Nergall
Do these designs build light enough for a good 3D airplane?
[QUOTE=pitrfh;33068127]very good scale not seen because there is nothing to reference.[/QUOTE}

Yeah, nothing in the photo to indicate relative size but it is 28% size, 85" wingspan powered by 60cc gasoline.

It weighs 17.5 lbs. I flew a 35 lb P-47 with this same motor and it was quite powerful but not any comparison to 3D type flying.

Dave


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