Giant Scale Kawasaki Ki100 Build

[JohnBoren]

I started this build I believe back in November. It is a scratch designed and built model. Wingspan is right around 82-1/2" I believe. All up flying weight should be under 16 pounds. The heaviest part on this bird are the retracts and motor. I welcome any questions you may have on this model. My next big decission is whether or not I should add flaps to the wing.

Sorry about the two images that are not realted to the Kawasaki.


John Boren

[JohnBoren]

Here are more photos.

John Boren

[earthsciteach]

Very impressive build!

[CHELLIE]

I See a Master Builder at work here

[xmech2k]

+1 what she said! And welcome to WattFlyer, John! Funny, most of the first time posters are total beginners, so you've made quite an entrance! I look foward to seeing this project come together.

[dgjessing]

Just amazing... I don't think I could bring myself to fly something with that much work in it . That aileron actuation scheme is really neat - is that your idea?

[JohnBoren]

Thank you for the positive comments on this build.

That aileron actuation scheme is really neat - is that your idea?

No, you can find informaiton here about that
http://www.geniebuild.com/g2_instructions.html


I started this build over on RCGroups in the Electric WarBird section. There is tons of text to read there if anyone is interested. I tend to be a creature of habbit and since I started my web presence on that forum I seldom go any place else which I am seeing is a big mistake since sites like this have a lot to offer as well.

I needed something simpler to create this winter compared to last winters project. Here is a link to pictures of last years build.

http://www.johnboren.com/html/kayaba.html

John Boren

[riverrat]

John

I will add a WOW!
Superb Chraftsmanship.

Glab you came over here.
I think you will like it.

Welcome!!

Regards
Jimmy

[Bill G]

Lovely undermodeled subject, especially for Zero and FW190 fans. I've had this one on the list forever, and can't remember the last time I've seen one built. The only plans I can remember seeing are the plans that Traplet used to advertise in Flying Scale.

[gramps2161]

John welcome aboard stunning build you have going on, and glad you stopped in to share your skill's.
I thought making a pocket and just leaving the servo arm and rod exposed was great. That servo setup is excellent!

[JohnBoren]

I’ve gotten over that last big hurtle, fiber glassing the cowl. It’s a dirty, itchy job that I really hate doing. Last night I laid the glass cloth. This morning I got out my palm sander and sanded it smooth. I then applied a coat of resin and micro balloons over the entire cowl. I let this set under a heat lamp for about eight hours and then sanded it smooth. Next I removed of all that foam from the inside. This I did with a large screw driver and one of those circular Exacto knife blades used for gouging out bowl like shapes. It also worked great for scrapping that last bit of foam off the inside of the fiberglass cowl. I’m sure the shape of this cowl isn’t perfect but its close enough. The cowl on the real Kawasaki has so many different contours to it that with out factory drawings I’m not sure how one would duplicate it exactly.

For the heck of it I placed the model with retracts, wheels, brushless motor and mount on a scale and right now it comes out at 8 pounds 10 ounces, so I see no reason why this bird won’t be quite a bit under 16 pounds ready to fly and with all the wing area this model has it should be a real floater.

John Boren

[kyleservicetech]

Originally Posted by JohnBoren

I started this build I believe back in November. It is a scratch designed and built model. Wingspan is right around 82-1/2" I believe. All up flying weight should be under 16 pounds. The heaviest part on this bird are the retracts and motor. I welcome any questions you may have on this model. My next big decission is whether or not I should add flaps to the wing.

Sorry about the two images that are not realted to the Kawasaki.


John Boren

Holy Cow, that is an impressive project! Keep us informed on how it flies, performs and so on.

What are you using for the electric power system? Funny, every time I weigh one of my models, there always seems to be an added pound or something that shows up when its ready to fly. . Even still, these electric motors really haul when they're properly matched to the model. My Hacker A60-16M motor with a 19X12 prop, 12S2P A123 battery pack hauls the 16 pound Giant Big Stick model straight out of sight up at full power.

Some reading information:
Giant Scale Power System:

Battery Backup System
http://www.wattflyer.com/forums/showthread.php?t=63794

Carl Goldburg Extra 330 Electric Conversion
http://www.wattflyer.com/forums/showthread.php?t=59273

Giant Scale electric motors vs Gasoline Engines
http://www.wattflyer.com/forums/showthread.php?t=58035

Great Planes Giant Big Stick Electric Conversion
http://www.wattflyer.com/forums/showthread.php?t=65052

Giant Scale Cessna Model
http://www.wattflyer.com/forums/showthread.php?t=66414

[JohnBoren]

What are you using for the electric power system?

Several years ago when COX Models was producing the line of Pica ARF's they came out with an electric conversion for these kits. For a short time they sold COX Outrunner Motors that were 5030/18. It flew the Pica T28 perfectly so it should do equally well on this model also.

Thanks for all the links, I'll check them out.

John Boren

[JohnBoren]

The little birdie inside me won the debate concerning adding flaps to the Kawasaki. It took about three hours today to complete the wing portion. I now need to figure out how I will make the actual flaps.

The first image shows the outline of the flap. I simply cut along the lines with a sharp Exacto knife. The foam I used on this model is really poor so instead on cutting nice and clean in kind of balled up on me. After making sure both the left and right flap cutouts where the same depth, “Well Close Enough Anyway” I made up a set of inserts that consist of a sheet of firm 1/32” balsa and a 3/8” balsa leading edge. I used epoxy to glue them in place, one at a time. I placed the wing back into it’s foam cradle, “You NEVER throw these away” well at least until the model is complete and ready to fly. The cradle will maintain the trailing edge shape since it has been weakened by cutting out the bottom portion of the wing. While the glue was setting up I used a nice flat balsa block to press the sheeting down until the glue set. I also placed a piece of balsa on the top and bottom of the trailing edge and clamped it in place until the glue was set. A few passes with my wood plan and sanding block and it was done.

John Boren

[JohnBoren]

I’ve been working on the front wind shield for the past couple of weeks off and on. I’ve cut at least four new sets of parts and today by re-cutting the front three sections by hand I believe I have something usable. To assemble these parts I glued and square up the rear three pieces. I then tapped the front three pieces in place aligning all the edges. I few drops of glue in couple of places and I had the whole assembly put together. Three hours later I got it fitted to the fuselage area pretty well. I will need to fiberglass this portion of the fuselage before mounting the wind shield in place so I can then finish blending it in.

[baz49exe]

Lovely job on the canopy John.
The whole build is superb but the canopy really sets the tone for me. I always find the glass work the most difficult part of any build.

Barry

[JohnBoren]

I got a little more done on the cockpit canopy. Next comes the plug for the vacuum section at the rear.

John Boren

[JohnBoren]

I’ve done a little more work on the Kawasaki. The first two photos show the inside of the cowl and the application of Kevlar Tow and resin along the cowls edge and plywood mounting flange. With out this the wood would have separated itself from the glass sooner or later. The Third photos shows a lay up of five layers of light cloth to make the access hatch on the side of the fuselage. I’ll most likely but the retract fill valve inside this area and I’m sure something else. The last photos show this hatch on the real airplane

I’m at the stage right now where I need to make decisions on how to proceed and until I do I’m kind of stuck. For instance do I create a complete cockpit for this model or just put in an instrument panel and flat floor just below this. Do I glue all the canopy sections in place or should I have the center one slide back. How should I activate the ailerons and flaps? My first thought was to put servos out in the wing under hatches. That would take four hatches to hide the servos. Not only is this a lot of work it looks ugly. Now that I have flaps cut into the lower surface, I could run long torque rods through the flap cut outs and have my servos inside the fuselage mounted on the top surface of the wing. I could do the same for the flaps.

Anybody have some suggestions they would like to throw out there.

John Boren

[Bill G]

I've somewhat changed my practices on serviceability over time. I prefer 100% serviceability, but realistically as long as I can reasonably get in there and service something in the event of a failure, I'll go that route, in efforts to have a better looking/functional scale model. I haven't had many servo failures, and if I were to have an aileron servo failure for example, it's quite likely that the wing repair required after cutting the wing sheeting to r&r the servo would be the least of the repairs, given the crash that had likely happened. It's interesting how elevator servos are generally 100% serviceable, although an elevator servo failure generally has a 99% chance of causing a crash.

The flap servo torque rod setup is practical, as the rod is relatively short and you also have the weight benefit of needing only one servo. I used that setup recently on an HE51.

I can understand wanting a scale cocpit on such a nice model. It's tough to have 100% scale all the time, but a somewhat recessed floor with a full torso pilot generally does the job. I've fabbed a number of torsos for the William's Brothers pilots, as mounting a plate just below the window line with nothing more than the pilot's shoulders and head showing doesn't quite have the look, and looks really ARFed.