BluCor - Nakajima Ki-43 Hayabusa "Oscar"....profile scale,built from 3-view drawings

Rad Racer · Dec 01, 2007, 11:14 PM

I have always liked the profile of the Nakajima Hayabusa, so I decided to build a profile scale from 3-view drawings I found online.

This build log will show you the steps I used to complete this airplane.....enjoy.

Step one:

convert and scale the 3-view drawing.

Rad Racer · Dec 01, 2007, 11:21 PM

This is my first build. The test flights went ok, but found it needed a few tweeks before it is ready for prime time

Rad Racer · Dec 01, 2007, 11:33 PM

The plans were scaled for a 24" wingspan. The plans were printed using a 60" inkjet plotter.

I cut out the plans with a Exacto blade. The plan templates are traced onto the BluCor foam using a Sharpie pen.....the residual ink is easily removed with rubbing alcohol.

BluCor cuts easily with a "fresh" exacto blade.

Rad Racer · Dec 01, 2007, 11:51 PM

Fuselage assembly is easy and quick. My design uses a lock/alignment tab system that makes for a straight/strong fuselage.

I have found "Gorilla Glue" works perfect with BluCor. I use a light Coat of Gorilla glue on all the joining surfaces then simple slide the fuse parts together for assembly.

Although this glue is meant to have the surfaces wetted before the glue is applied....I discovered if you do not wet the surfaces the glue still works, but you don't get so much foaming from the joint on to other surfaces.

I really believe Gorilla glue will replace epoxy.....it's that good!

Xanadu · Dec 02, 2007, 09:06 AM

The pros and cons of Gorillia glue is the it foams, and it foams.

Good to expand and foam up a bit to get all those hollow spots, but bad to foam since it leaks out all the edges too.

One way around leaking out is to put painters tape over the seam line, stops the foaming out.

Rad Racer · Dec 02, 2007, 09:17 AM

Good hint....I will keep that in mind as I complete this build.

thanks
Wayne

Rad Racer · Dec 02, 2007, 09:44 AM

The airfoil shape is added to the wing with the following technique....it's really slick.

I first saw this method used by the guys at Rabidmodels.com. To my knowledge, they use this method of airfoil forming on all their foamy warbirds. Checkout their website, they have some really cool warplanes.

This process gives the wing a natural curve or airfoil shape, you also get tip washout if the fold lines are layed out correctly.

I found the sharp edge of a board works great for creating these creases, it does not cut into the plastic skin.

kram242 · Dec 02, 2007, 10:00 AM

Nice build, do you have the vector version of the plans to share?
Thanks
Mark

Rad Racer · Dec 02, 2007, 10:11 AM

Here you can see the natural arc or airfoil shape created by creasing the under side of the wing.

The wing slides nicely into the ClarkY cutout in the fuselage.

During the test flights of the prototype, I found the plane wanted to climb excessively, in-fact I needed a fair amount of down elevator just to maintain level flight.

At first I thought my CG was off, but found even shifting and adding nose weight really didn't help. My next thought was that my thrust line was postive...that to checked out fine and wasn't the problem.

I went back to my plans and looked at the incidence angle of the wing....it was 3 deg., exactly where it should be. I started to wonder about the airfoil and where it started to generate lift. After some quick analysis with Profi Pro, I discovered the problem.....a ClarkY foil starts generating lift at -3 degrees. My original design added +3 degrees of incidence, so the wing effectively had 6 deg of incidence, too much for this model.

Rad Racer · Dec 02, 2007, 10:29 AM

Quote:

Originally Posted by kram242

Nice build, do you have the vector version of the plans to share?
Thanks
Mark

Thankyou. I will share the plans, but I am not sure of the best format.

I typically like to use DXF files, but see many of the plans on RC Groups are in paged PDF format so people can print them on their home printer.

Not sure how these "paged" PDF files are made, so if someone wants to volunteer to make the PDF file...I will gladly supply the design in DXF format.

Rad Racer · Dec 02, 2007, 01:32 PM

How is this for a profile match, almost looks like the real thing (well, accept for the tail in the snow bank thing)

Rad Racer · Dec 02, 2007, 07:34 PM

These photo's show the wing assembly.

Apply plenty of Gorilla glue to the wing ends and fuse cutout. Pins are needed to keep everything square and held together until the glue dries.

Rad Racer · Dec 02, 2007, 07:38 PM

Enough for today....time to let the glue setup.

Rad Racer · Dec 02, 2007, 08:18 PM

Here are the plans for the Hayabusa.

kdahlhaus · Dec 02, 2007, 08:46 PM

Looks great. Another good profile foamie - don't forget to add it to the list of plans at the start of this forum.

Dec 01, 2007, 11:14 PM	#1
Rad Racer Try, how hard can it be? Join Date: Jan 2004 Location: Jordan, Minnesota Posts: 568	BluCor - Nakajima Ki-43 Hayabusa "Oscar"....profile scale,built from 3-view drawings I have always liked the profile of the Nakajima Hayabusa, so I decided to build a profile scale from 3-view drawings I found online. This build log will show you the steps I used to complete this airplane.....enjoy. Step one: convert and scale the 3-view drawing. Attached Thumbnails 3-view drawing found online. 110.0 KB · Views: 341 Final CAD plans. The 3-view JPG was coverted to raster graphics and pulled into my CAD system. I keeped only the necessary lines (plane outline), all other lines were deleted. 54.4 KB · Views: 525 Last edited by Rad Racer; Dec 02, 2007 at 10:36 AM.

Dec 01, 2007, 11:21 PM	#2
Rad Racer Try, how hard can it be? Join Date: Jan 2004 Location: Jordan, Minnesota Posts: 568	My first build. This is my first build. The test flights went ok, but found it needed a few tweeks before it is ready for prime time Attached Thumbnails First build of this model. 110.6 KB · Views: 370 another shot. 51.8 KB · Views: 429

Dec 01, 2007, 11:33 PM	#3
Rad Racer Try, how hard can it be? Join Date: Jan 2004 Location: Jordan, Minnesota Posts: 568	The plans were scaled for a 24" wingspan. The plans were printed using a 60" inkjet plotter. I cut out the plans with a Exacto blade. The plan templates are traced onto the BluCor foam using a Sharpie pen.....the residual ink is easily removed with rubbing alcohol. BluCor cuts easily with a "fresh" exacto blade. Attached Thumbnails Plans were scaled for a 24" wingspan. 112.3 KB · Views: 256 All parts have been cut. 115.0 KB · Views: 282 Last edited by Rad Racer; Dec 02, 2007 at 09:19 AM.

Dec 01, 2007, 11:51 PM	#4
Rad Racer Try, how hard can it be? Join Date: Jan 2004 Location: Jordan, Minnesota Posts: 568	Fuselage assembly is easy and quick. My design uses a lock/alignment tab system that makes for a straight/strong fuselage. I have found "Gorilla Glue" works perfect with BluCor. I use a light Coat of Gorilla glue on all the joining surfaces then simple slide the fuse parts together for assembly. Although this glue is meant to have the surfaces wetted before the glue is applied....I discovered if you do not wet the surfaces the glue still works, but you don't get so much foaming from the joint on to other surfaces. I really believe Gorilla glue will replace epoxy.....it's that good! Attached Thumbnails Fuselage assemble is easy and quick 109.2 KB · Views: 302 Notice the alignment tabs or keys, makes for a straight/strong fuselage. 78.4 KB · Views: 214 I use the same locking tabs in the back. 74.2 KB · Views: 238 66.5 KB · Views: 175 Last edited by Rad Racer; Dec 02, 2007 at 09:49 AM.

Dec 02, 2007, 09:44 AM	#7
Rad Racer Try, how hard can it be? Join Date: Jan 2004 Location: Jordan, Minnesota Posts: 568	The airfoil shape is added to the wing with the following technique....it's really slick. I first saw this method used by the guys at Rabidmodels.com. To my knowledge, they use this method of airfoil forming on all their foamy warbirds. Checkout their website, they have some really cool warplanes. This process gives the wing a natural curve or airfoil shape, you also get tip washout if the fold lines are layed out correctly. I found the sharp edge of a board works great for creating these creases, it does not cut into the plastic skin. Attached Thumbnails The blue dashed lines are crease lines. This layout provides for natural washout at the tip. 115.0 KB · Views: 251 I use the shape edge of a cut board for creating the crease. Simply press the board edge into the foam. Please note: you do not want to cut the plastic skin...it gives the wing much strength. 117.2 KB · Views: 308 Pressing the crease lines into the foam 111.0 KB · Views: 261 Last edited by Rad Racer; Dec 02, 2007 at 03:30 PM.

Dec 02, 2007, 09:06 AM	#5
Xanadu Trailer Parts Guy Join Date: Nov 2006 Location: Anola, Manitoba, Canada Posts: 869	The pros and cons of Gorillia glue is the it foams, and it foams. Good to expand and foam up a bit to get all those hollow spots, but bad to foam since it leaks out all the edges too. One way around leaking out is to put painters tape over the seam line, stops the foaming out.

Dec 02, 2007, 09:17 AM	#6
Rad Racer Try, how hard can it be? Join Date: Jan 2004 Location: Jordan, Minnesota Posts: 568	Good hint....I will keep that in mind as I complete this build. thanks Wayne

Dec 02, 2007, 10:00 AM	#8
kram242 -+- PhlatBoyz -+- Join Date: Sep 2003 Location: New Jersey Posts: 1,313	Nice build, do you have the vector version of the plans to share? Thanks Mark

Dec 02, 2007, 10:11 AM	#9
Rad Racer Try, how hard can it be? Join Date: Jan 2004 Location: Jordan, Minnesota Posts: 568	Here you can see the natural arc or airfoil shape created by creasing the under side of the wing. The wing slides nicely into the ClarkY cutout in the fuselage. During the test flights of the prototype, I found the plane wanted to climb excessively, in-fact I needed a fair amount of down elevator just to maintain level flight. At first I thought my CG was off, but found even shifting and adding nose weight really didn't help. My next thought was that my thrust line was postive...that to checked out fine and wasn't the problem. I went back to my plans and looked at the incidence angle of the wing....it was 3 deg., exactly where it should be. I started to wonder about the airfoil and where it started to generate lift. After some quick analysis with Profi Pro, I discovered the problem.....a ClarkY foil starts generating lift at -3 degrees. My original design added +3 degrees of incidence, so the wing effectively had 6 deg of incidence, too much for this model. Attached Thumbnails Here you can see the natural airfoil shape created by creasing the bottom surface of the wing. 66.7 KB · Views: 249 The wing slides nicely into the cutout in the fuselage. I used a ClarkY airfoil in this design....judging from the test flights of the prototype, it seems like a good choice. 63.8 KB · Views: 295

Dec 02, 2007, 01:32 PM	#11
Rad Racer Try, how hard can it be? Join Date: Jan 2004 Location: Jordan, Minnesota Posts: 568	How is this for a profile match, almost looks like the real thing (well, accept for the tail in the snow bank thing) Attached Thumbnails 58.5 KB · Views: 345 111.0 KB · Views: 206

Dec 02, 2007, 07:34 PM	#12
Rad Racer Try, how hard can it be? Join Date: Jan 2004 Location: Jordan, Minnesota Posts: 568	These photo's show the wing assembly. Apply plenty of Gorilla glue to the wing ends and fuse cutout. Pins are needed to keep everything square and held together until the glue dries. Attached Thumbnails Draw line 1/8" in from the edge. This line is used to make sure each wing is inserted halfway into the fuselage. (Blucor is 1/4" thick) 59.8 KB · Views: 271 1.53" dehedral blocks installed. 118.7 KB · Views: 286 wing inserted into fuselage. 59.0 KB · Views: 242 Apply plenty of Gorilla glue to the wing ends and fuse cutout. Pins are needed to keep everything square and held together until the glue dries. Besure to sight down the fuse....make sure tail is square with wing. 64.6 KB · Views: 291

Dec 02, 2007, 07:38 PM	#13
Rad Racer Try, how hard can it be? Join Date: Jan 2004 Location: Jordan, Minnesota Posts: 568	Enough for today....time to let the glue setup. Attached Thumbnails Ok, the major assembly is complete. Be sure to let the glue dry before moving assembly. 107.0 KB · Views: 322 103.3 KB · Views: 282

Dec 02, 2007, 08:18 PM	#14
Rad Racer Try, how hard can it be? Join Date: Jan 2004 Location: Jordan, Minnesota Posts: 568	Hayabusa plans Here are the plans for the Hayabusa. Attached Files HAYABUSA-24IN.pdf (64.1 KB, 921 views) HAYABUSA-24IN.zip (57.1 KB, 455 views) This is the DXF plan file. This file can be used to resize or modify the plan. Last edited by Rad Racer; Dec 02, 2007 at 08:46 PM.

Dec 02, 2007, 08:46 PM	#15
kdahlhaus Registered User Join Date: Mar 2002 Location: USA, OH, Cleveland Posts: 2,930	Looks great. Another good profile foamie - don't forget to add it to the list of plans at the start of this forum.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Discussion Warbirdkits.com Nakajima Ki-84-i Hayabusa "Oscar"	St. Martin	Scale Electric Planes	69	Jun 12, 2006 09:35 AM
Alfa Nakajima ki-84a Hayate	CUBANO8	Parkflyers	24	Jun 26, 2005 08:04 PM
Hobby Lobby Nakajima KI-84a, Anybody flying One?	WhiteCloud	Parkflyers	11	Jan 15, 2005 08:05 PM
Royal Thai Airforce KI-43	wespe	Scale Electric Planes	5	Jan 13, 2004 04:54 PM
Nakajima Ki-44 "Tojo"	LawnDart	Scale Electric Planes	1	Nov 02, 2001 06:50 PM