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Jan 29, 2011, 12:20 AM
AndyKunz's Avatar
Build Log

Micro Kaos Build Thread

I've been getting the itch to build something Pattern for a few weeks, but haven't had any time. This weekend suddenly opened up for me, so I mooched a broken UMX Beast from Quique to use as a donor for a micro Kaos. I'll be using the receiver brick, motor, and aileron servos.

I printed a set of old Kaos fuselage drawings (for the outline) to give a 27" span (I was aiming for 25" but whoopsed). Next, I used Profili Pro to make a wing plan and ribs to match using a NACA 0018 airfoil.

I cut out the fuse sides from some 1/32" I had around. These two sheets were a pair, and had harder wood at one end and lighter at the other - perfect for a stiff nose and light fuse tail!

I added 1/8" square around the perimeter of the fuse sides with a couple cross-braces. While that was drying I cut out the tailfeathers from 1/32" hard sheet. The stab was braced by sandwiching a border of 1/32" around its perimeter as well. The fin is simple sheet with a cross-grain tip butted to it.

Next I used 3M #77 to tack glue the rib patterns to medium 1/32" sheet, then started cutting them out (with a new #11 blade of course).

Then I came over to my PC and posted this for you all. Tomorrow morning I'll join the fuse sides and build the wings. It'll have trike gear (like all REAL Pattern planes) but I want to bring it to work Monday ready to fly, so no retracts.

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Jan 29, 2011, 02:24 AM
sand it - round?
Vic101's Avatar
Looks great!

Those old designs are classics, what colour scheme are you thinking of doing?

What percentage thickness have you gone with for the wing, it looks like a good 12% or so?

Looking forward to the progress, thanks for posting!
Jan 29, 2011, 10:40 AM
AndyKunz's Avatar
It will probably be similar to my 40-sized one, if I can find some orange ParkLight soon!

Getting a slow start today.

Airfoil is NACA 0018 (18%).

Jan 29, 2011, 12:04 PM
Paul Pappas,.....AMA....L42520
Pitstop000's Avatar
Originally Posted by AndyKunz
It'll have trike gear (like all REAL Pattern planes)

I like That !
Jan 29, 2011, 03:51 PM
AndyKunz's Avatar
The cross-braces for the fuselage are minimal. The lower ones have a little more beef since they'll be tying the wing to the fuse. The one in the top front is where the hatch will begin, so it's got a little more meat there too.

The brick will be mounted on the left side of the fuse as shown, using 1/8" sq to provide a stand-off so the servos' gears don't bind. This location is dictated by the arrangement of the servos on the brick. The lower servo is the rudder, which will tie to the nose gear and I want to keep it as low as possible for maximum battery room.

The left wing is ready for some trimming and sanding. You can see the main gear block - it's just hard 3/16" sq balsa.

In a few minutes I'll be fabricating the nose steering mechanism. I need to get that done before joining the fuse sides.

Jan 29, 2011, 05:46 PM
Gravity sucks.
mrittinger's Avatar
Wow, 18% is pretty thick, but it'll perform well.
My Mini CurarE is about 15% if I recall....flies great too.
These old ships fly beautiful with modern power setups and build type

Jan 29, 2011, 06:03 PM
AndyKunz's Avatar
Yeah, but you know how inaccurate things get and how Reynolds screws everything at a chord this short. The idea is for more drag - this is an indoor plane with a target weight of 120g. 15% is what I used on the 100 MPH Gulfstreams.

Jan 30, 2011, 04:26 PM
AndyKunz's Avatar
The fuselage is finished. The cheeks have extra wood around them to allow sanding to a smoother contour.

The hatch is friction fit. Inside you can see how the nose gear steering is accomplished. Those are two small 1/8" ply plates separated by little more than the thickness of a 1/16" ID wheel collar. The collar will allow me to adjust the height to change the AoA on the ground.

The UMX Beast motor is mounted on a plastic fixture that makes beam mounting easy. What's more realistic than a beam-mounted engine. Those beams are medium balsa, though, not maple.

The wing tips have just been attached. They will be formed to shape once the glue dries. You can also see the rails near the root rib that will mount the 1.5g linear aileron servo.

Jan 30, 2011, 11:14 PM
AndyKunz's Avatar
Somebody asked about weight. My target is 100g, with a 120g absolute max.

All the wood parts weigh 42g as they are shown in above photos. The tips will lose a little, but the root will gain some, and the ailerons will be trimmed to length so I figure that's a good estimate for the whole thing.

The brick, motor, and servos are 22g.

I haven't trimmed the gear wires yet, nor made pushrods, nor added the battery, nor the covering. Those will add a few grams but I should be within the 100-120g range.

Feb 01, 2011, 05:49 PM
Closed Account
Looks like a Kaos?!? Only a 27 inch wing span? Ithink your going to want to keep it close in!
Feb 01, 2011, 06:01 PM
AndyKunz's Avatar
How big is your Super Kaos build? Did I make 25%? It'll be my IMAA entry

If it weren't for this storm I'd be covering it tonight.

Feb 02, 2011, 07:04 AM
Closed Account
You guys and your giant scale airplanes! By my calculations this airplane is just under 48% scale. I'm building the Super Kaos which has a w.s. of 58 inches. I don't know what the plain old Kaos w.s. was.
Feb 02, 2011, 08:07 PM
AndyKunz's Avatar
We had off today due to the storm. So amongst other things, I got a little playing in. All the white covering is done. Tomorrow I'll pick up some orange Park Lite and do the leading edge and tips on the tail. I have black and silver striping as well as some stickers to lend a little more color.

The plan is still to fly it Friday evening at the Armory!

Feb 02, 2011, 08:11 PM
Paul Pappas,.....AMA....L42520
Pitstop000's Avatar
Looking Good Andy! Home Strech time.
Feb 02, 2011, 08:40 PM
UFO Driver
R_G's Avatar
This has to be one of the fastest builds on record!
Less than a week from the first drop of glue to covering, and it looks great to boot!

Very Cool!

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