Pubhi

My Feedback: (5)

Well, I lost my keecat the other day at the field when it struck a tree. It was completely my fault and I was unable to judge the relative location of the tree and the plane. Anyway, all the electronics survived and 90% of the fuselage was undamaged.

Now onto the fun part. I have another keecat waiting in the box to be built and I am going to modify this one to work with a .82 K&B engine turning a dynamax fan. I am also going to lose the elevator and build this one with canards. I will be keeping both of the tail booms but they will be shortened and strengthened with carbon rods and carbon fiber sheets since there won't a horizontal stab in the middle to support them. I'm also going to be replacing the stock landing gear with something better. I don't like the nose wheel steering mechanism being exposed. It looks ugly and it would be easily damaged in a belly landing.

The original idea was to redo the fuselage so that I could place the fan inside and run some ducts but i'm not so sure that there is enough room for all that. The fan should be coming in the mail in a couple of days so I will have a better idea at that point. If I do choose to keep the engine inside the fuse then I would have to spend another $150 on a spring air kit. I would also have to figure out how to run the ducting and that would probably take a considerable amount of time to complete.

I'm really excited about this because this airplane flies so well that it will look nothing but awesome with a ducted fan and canards. I should be able to do some really high AOA maneuvers, tight loops and awesome landings. I'll be posting pictures as I go along.

I do ask that you guys share your knowledge and help me improve the design. I'm currently trying to figure out the best way to strengthen the stock tail booms. I'm planning on burying carbon rods and then lining the the entire boom with carbon sheets and epoxy. It should make for a very strong boom but I want to keep the weight as low as possible. I'm sure there is a better way out there and i'd really like to hear what you guys have to say. Stay tuned.

learjet45xp

Hmmm....sounds like a cool idea. The canards sound fun....might put a couple on mine just for kicks. Maybe make it where they can be mixed to only work in the last 15% or so of the elevator throw.

Pubhi

My Feedback: (5)

Well, I finally found the time to get started on the rebuild and I started off with the tail booms. To make them stronger, I decided to embed them with carbon rods for internal support and then glass the exterior with epoxy and henry's fiber cloth. This should help to keep the weight fairly low and add a lot of strength. I should be able to finish off the tail booms completely tomorrow and then i'll get started on the engine mount or canards. I might actually do the canards first. I also decided to go with some spring air retracts and they should be coming in next week or so.

Enjoy the pictures.

BillS

Here is a thought about the canard.

Bill

Pubhi

My Feedback: (5)

How well do they work bill?

BillS

I am still learning to fly the stock airplane and have not use the canard. The wind has prevented testing this week.

If the airplane survives the learning process I will install the canard. If the canard works I will move the booms forward one inch at a time. The elevator will also be used until the flight characteristics with canard are understood. Gradually I hope to remove the need for elevator and reduce the weight at the rear and the total weight of the airplane.

The canard is simply aileron stock attached to music wire and removable. It rotates in two hardwood blocks glued to the fuselage sides. Likely the canard will need to be larger or further forward on the fuselage if the elevator is removed.

Good luck with your project.

Bill

Pubhi

My Feedback: (5)

Bill,

Your bobcat looks pretty good with the canards. Once you get the hang of it, you will have a great time flying it. These bobcat type planes fly extremely well and look real nice while doing it. The best part about delta wing A/C is the landing cuz it will flare much like the real thing and hold it for a high AOA landing.


UPDATE-

I finished up both the tail booms today and they are completely glassed now. I made the mistake of using gorilla glue on one on the tail booms instead of epoxy around the carbon rods. As a result, it twists a little more easily than the one that is being held together with epoxy. I don't think it will be much of an issue on the plane but I will be sure to use epoxy for the rest of the plane. I might just end up putting some carbon rods in between the two booms to stiffen it up a bit and keep them from twisting in flight.

I also went ahead and embedded the control rods for the ailerons inside the tail booms as shown in the pictures. The control rods will be connected to the servo which will be located inside the fuse with the use of a bell crank, which is located inside the inner wing panel...as shown. I wanted to make this plane very clean and this will definitely go a long way to achieving that goal. It actually turned out to be a fairly easy setup.

I'll be getting started on the engine mount tomorrow and i'll post up more pictures when its complete. Enjoy.

Pubhi

My Feedback: (5)

I decided to go ahead and build up the plane with tailerons first since I have never flown with a ducted fan before. The tailerons will be located down low on the outsides of the tail booms and both will operate independently much like an F-18. Each one will be controlled with hitec HS-625MG servos which will both be embedded in the inner wing panels as shown in the picture below. I am embedding all the control rods inside the booms so that very little will be exposed and this should make for a very clean keecat. Once I get all the bugs worked out with the plane, I will go ahead and add some canards to supplement the tailerons. For those of you who have seen the Mig-29 with canards, the keecat will looks very similar to that when I am done with it.

Both tailerons will be embedded with carbon rods to control the movement and the entire surface will be movable. To keep the system efficient and quick, the rods will be rotating inside of 5mm bearings, which can be seen in one of the pictures below. It was fairly straight forward to build everything up but when working without plans, problems always come up and it ends up taking way more time than you expect to spend. Anyway, its coming along nicely and i can't wait to see this thing in the air. I'm actually kinda surprised that so few of you even have anything to say on this...I guess it must be lame or something.

NOTE- The servo will be covered up tomorrow...

Razor-RCU

My Feedback: (50)

It is not lame it is pretty interesting actually. Where do you fly in San Diego, I would love to come check this out when you fly it....

Keep us posted!

Pubhi

My Feedback: (5)

I'm actually stationed in Meridian, MS at the moment. I used to live in La Jolla though when I was going to UCSD....can't wait to go back someday. I never did find a flying field down there but I flew my wings at North Torrey pines beach in Del Mar. You should try it out if you haven't already. You will want to come and fly there every single day once you get a taste for it. I will post up some good videos for you guys when there is something worth taping. Thanks for the comments.

learjet45xp

Naw..its a pretty cool build ya have going on there. I am trying to find some canards for mine also. I want to buy some from a jet kit like the rafale jet and put them on. It looks like you have alot of epoxy going on there, any concern about weight?

Pubhi

My Feedback: (5)

It actually looks worse in the pictures than it really is. I only used epoxy on one side of the booms and the other side is 3M high strength adhesive. The total weight for each boom with the covering is about 7oz so its really not that bad. This plane can handle the weight without problems so i'm not too worried. I'd rather have it be a little more than and know that it will hold together. I'm almost done with the tailerons and i'll be covering up the tail booms tonight.

Crazy4Flight

My Feedback: (540)

your first picture shows the D/F and and auxillary prop engine...never thought of making it a twin.[sm=bananahead.gif]

Pubhi

My Feedback: (5)

Yea...I must have been high off the epoxy and all the other adhesives i've been using to build this thing.


UPDATE--

Anyway, I had a chance to work on the tailerons some more. I found a 5mm shaft off a small R/C helo that worked perfectly with the 5mm bearings i've been using for the tailerons. The pictures below show how they are embedded into the aft portion of the tail booms. I'm going to be using a total of 4 bearings to ensure smooth operation. I also cut out some control surfaces out of cardboard to see how they would look on the plane. I think I will end up making the actual surfaces a little bigger even though I don't think control will be an issue. I have never built up wings for anything so this will be my first. I want to shape the tailerons after the F-18 and I can't decide if I should just take two pieces of wood and sand them down or if I should make some ribs and build it up like a real wing. What do you guys think??

I will also be connecting both the tail booms with two rods. One is made of wood and the other will be a 5mm carbon rod. I'm going to join the two running parallel like an airfoil to cut down on drag. They will be joined to both tail booms right above the bearing blocks for the tailerons. This should work well and keep the tail booms rigid under load while being light weight. The total weight for the A/C as shown in the picture below is 4lb and 1oz. The weight with the engine thus far is 7lbs. I'm predicting the total weight will be somewhere in the range of 10-11lbs. My goal is to finish up the tail booms and tailerons this weekend and start work on the engine mount. I'm afraid I might be waiting around a while for my spring air retracts to get here. I ordered them over a week ago and called yesterday to find out when I can expect to receive them and I was told "as soon as possible"...***? Anyway, enjoy the pictures for now.

learjet45xp

Wow....you are seriously dedicated to the restoration of that plane. Very cool! Can't wait to see the finished product. I have sent e-mails to a few rafale manufacters about buying the canards, but no reply yet. I think I will try them and some winglets on mine...should look cool. I got super pissed off at my keecat yesterday and in about 20mph winds decided I was gonna go for broke. My intention was to actually crash the plane. Instead I ended up pulling off some crazzzzyyyy tricks....shes still in one piece. I can honestly say that it is one of the strongest planes I have ever flown...anything else would have surely snapped the wings or tail off with the stuff I was pulling.

BillS

Thanks for the pictures. The project is interesting.

Bill

Pubhi

My Feedback: (5)

Yea man, I really want to see this thing fly...or so I hope. I hope you are able to find some canards but i'm afraid you will end up forking over a good amount of cash to get them. Its not very difficult to make your own out of some balsa and laminate them over with some light weight fiber cloth and epoxy. I'm doing something similar for mine and they are extremely strong. As far as the keecat goes, yea it is a very well built plane. It can easily handle a turbine for those who have one. I hope to built a keecat type plane with a turbine someday...


Bill,

Thanks for the comments...I can't wait to see the end product myself.

UPDATE--

I'm about 80% finished with the tailerons and the epoxy is curing as I type. I should be able to finish them up tomorrow. I took me a good 6 hours to finish as much as I did and it will probably take about 3 more to finish them up. I need to find some metal control arms that can be tightened down like a clamp around the control shaft for the tailerons. Anyone know where I may able to find something like this?? This is about all I have for now...i've added some pictures of my progress. Enjoy!

rglgatortail

My Feedback: (7)

very very interesting build I am very fascinated to see the end product. Only if i can get off my butt and finish my P-51 that i have been messing around with for over a year and that is only because i get lazy and dont wanna work on it, im at the point to do the final sanding and wheel wells and then covering. Keep the pictures coming.

Pubhi

My Feedback: (5)

Thanks RG...I know what you mean about being lazy sometimes. I was very lazy about this project and then I just decided to start it one day. Once I get something started, I don't stop till I finish it and that's why i'm just rifling though this one. It also helps that i've had two weeks off so what better to do than to work on this. I've never flown a ducted fan before so i'm pretty excited to see this one fly. If all goes well, it should be a very good looking and flying model.


UPDATE---

I had the chance to go ahead and finish up the engine installation today. I must it, It came out very nice and I was initially afraid that the weight on this motor and fan might be a bit much for the plane but now that it's all done, I can say with assurance that it is as solid as a rock! I wanted to have the ran located far up enough that I wouldn't have add a ton of weight in the nose to balance it. So, I had to cut off the small fiberglass fairing that was on the original keecat and build a platform for the fan to bolt to. You can see in the pictures that I ended up using some of the fairing on the finished product to make it look somewhat like the original keecat. It was a pretty simple installation but when you are learning/designing/engineering/building at the same time, it naturally take a lot more time to get things done.

I also tried to use as much gorilla glue as possible instead of epoxy to save weight. For those of you who have not used gorilla glue before, it is an absolutely amazing product. All you need is a bit of glue and a little bit of water to activate it. The result is a foam that expands and fills in all the gaps. The result is an extremely strong bond that will not give no matter what! Anyway, i'm going to be adding some of the electronics tomorrow and covering up the tail booms. I'm still waiting on the spring air retracts and I am doubtful that it will arrive by the end on this week. I really want to see this thing fly next weekend so I might just go ahead and install the mechanical gear for the moment. I'm very disappointed with spring air taking orders for something they don't already have in stock!!!

On another note, the total weight of the A/C with all the gear and electronics will be about 9.25lbs (add or take a few oz). The weight is extremely low compared to what this A/C is capable of. I'm hoping to get about 10lbs of thrust out of the fan so it should be interesting to see how it will turn out. Enjoy the new pictures.

Razor-RCU

My Feedback: (50)

Looks great!

As an aside, I have flown at Torrey, I went through my "Slope SOaring" phase. I have a full wingeron (Turbo) and some other stuff....There are several decent flying field here actually. I fly at the Chula Vista Club and was a long-time member of the Weedwackers in Lakeside.

At some point you might try as Hurricane fan unit for more thrust

BillS

You made a lot of changes all at once. I have wondered if the elevators were too far back. I have also wondered if ailerons would need to be mixed with elevator. Probably no way to find out until after a few successful flights.

Good luck with the initial flights.

Bill

learjet45xp

Any new updates? I am really looking forward to hearing how the tailerons work

learjet45xp

Ok...I started on my canards last night. Turned out pretty well. Took me awhile to figure out how to mount the bars into the canards themselves so they don't just twist. Ended up recessing a slot into one of the ribs and then putting a bar through my aluminum pipe and pulling it into the recess and adding expoy. Worked great! I also made the canard an airfoil, I don't really know if that was a good idea or not...I just really want to do slow high AOA stuff ....hopefully this will help. I think ifthe test flights go ok, I will change out my evo .61nt for my .91FX with jett pipe and swing that new 11x10 of zingers! Only time will tell how it goes. Also, I was thinking of adding some winglets. I don't think they would be hard to add and would make it look pretty cool, might help with tip stalls as well.

learjet45xp

Ugh! Finally finished!!! Thought the installation of the canards was going to be a quick process.....I thought wrong. Anyways, I would say a good 15 building hours later here, I am done. The problem is that I ran out of channels on my radio. I was going to make the canard not move all that much for the first flight and just use the elevator to counteract any bad tendencies. Well now I have it just Y'ed to the elevator and working with the linkage I was able to restrict its movement slightly. I think it moves a good 1 1/2" up and down on the trailing edge. I suspect that the pitch control will be extremely sensitive on the first test flight, hopefully not uncontrollably so. Anyways, here are some picks for your viewing pleasure

On another note, has anyone seen this video yet? awesome idea. Thrust vectoring,...problem is you need to be running electric.

http://www.youtube.com/watch?v=8JRyb...eature=related

cncswiss1

did you move you CG forward? adding the canards moved the CP forward, so the CG will need to move as well.

there is a thrust vectoring turbine out there, http://www.youtube.com/watch?v=766N1...eature=related