RysiuM

My Feedback: (1)

No long time ago I finished my "giant scale" SPAD - Piper Cub (CoroCub). It supposed to be my trainer, but despite the fact it really flies like a trainer, the take off and landings are quite scale (read: scary). So my next bet was on Spadet. I had Sig Kadet LT-40 for many years and I loved it. I was hoping to make something like that.

So I started it. All dimmensions were scaled up by 15% except the width of the fuselage - the size was determined by downspot width. Here are some pictures from the construction.

1. The fuselage - white coroplast 4mm.
2. The tail section - yellow coroplast 4mm with CF tubes (4mm)
3. The tail part of the fuselage.
4. I glued in two pieces of 4mm coroplast to create a slot that the vertical stab will hook on.
5. Detail of the tail section
6. Another look to the tail.
7. Center part of the fuselage. Yardstick not glued yet here
8. Nose part. I had to stack a few layers of 4mm coroplast in order to mount downspot properly.

RysiuM

My Feedback: (1)

The slot in the tail section was not the first, nor the last modification I made. In order to be able to mount the wing exactle at the same place in the fuselage I created a "notch" above the windscreen as a resting place for leading edge. There are others mods too, but I will get to them later. So for now more pictures of the fuselage.

1. Landing gear and engine mount is mounted.
2. Another view of the side of the fuselage
3. Plywood block inside the fuselage for LG mount.
4. Very important thing - bamboo sticks in the bottom of the fuselage where the landing gear is mounted. They not only protect thje coroplast from crushing but also spreading the force of the landing impact through entire bottom of the fuselage.
5. Horizontal stab also got CF tubes.
6. Another side of the tail
7. The horizontal stab is not only glued to the bottom of the fuselage but I added two screws - just in case. bamboo sticks under the screws are mandatory here.
8. Engine mount drilled for nose gear mounting.
9. That is how the nose wheel will turn.

draftman1

looking good! you got yourself a nice trainer there. I havnt seen your cub build in a while, I was wondering if you finished it. if you have pictures, post them on spadworld.net there are a bunch of spadders who would like to see this plane and the cub, keep up the great work!

RysiuM

My Feedback: (1)

Corocub is finished and it's in the air. The entire building thread including [link=http://rysium.home.comcast.net/~rysium/corocub/corocub_71.jpg]pictures[/link] and [link=http://www.youtube.com/watch?v=rbCT0Fa9j1E]video[/link] is on RCU in the thread [link=http://www.rcuniverse.com/forum/m_6396918/mpage_1/key_/tm.htm#]CoroCub - a little bigger one. [/link]. Unfortunatelly As you can see from th take-of and landing it is not a trainer per say ("first airplane"). However it trains for sure - how to land and take off

Spadet supposed to be "the first airplane" like SIG Kadet LT-40 is. Just a little tougher than the balsa one.

draftman1

I guess I missed the flight part of the thread. I got back into r/c after 20 yrs with the debonair model, yes it was a tough bird and a great trainer the spadett is also a wonderfull trainer also. the corro fuse just seemed like it would take longer to build than the downspout fuse of the deb. since then I have trained 4 to 5 people on deb's. I made mine larger with a 6 ft w.s. it was easier to see but took a larger engine and I had some elevator failure problems due to flexing in higher speed arobatics. I had to beef up the elevator alot and make sure the servo was closer and stiffer pushrods.

RysiuM

My Feedback: (1)

Here is the power for the plane. ASP 60 two stroke with Perry carburator. This engine killed my balsa plane (dead stick in the worst possible place) so I'm going to test this engine too. Spaded should handle crash landing well. The engine is 60 size but requires mount for 90. So if the engine will not cooperate I will replace it with 90-size four-stroke.

RysiuM

My Feedback: (1)

Now it's time do make a wing. Another modification - the little one. Because I had big piece of coroplast I decided to make the bottom part from one piece - will be stronger. I also decided to replace full span ailerons with ailerons and flaps. I hope flaps will help land this thing slow. Also I decided to cut ailerons and flaps in the bottom surface instead og fluing additional piece for control surfaces.

So here it is:
1. Bottom part of the wing - one piece of 4mm yellow coroplast
2. Plans are drawn straight on the coroplast. Line mark positions of the spar and ribs (about ribs a little later)
3. The center past of the wing. Each aileron will have it's own servo, plus one servo for both flaps.
4. Gluing a top part - 2 mm white coroplast
5. At the same time I glued servo bays
6. Servo bay for aileron servo

RysiuM

My Feedback: (1)

Now when the coroplast is prepared it is time to start building it. Another mod: the wing profile will be supported by ribs cut of pink foam. 2mm coroplast is quite soft and it is hard to make it stay in one shape to keep the sam profile along this big wing. Pink foam ribs placed 5 inches appart whould ensure that the wing profile stays the same - I decided to go with Clark-Y.

So another set of pictures:

1. Ribs cut from the pink foam board using templates for Clark-Y. I don't have foam cutting machine so I sanded the shape.
2. Ribs are cut and ready for installation
3. Ribs and spar installed. I used CA for spar and Gorilla glue for ribs. Then additional bed of gorilla glue for spar.
4. It takes about 1 hour for gorilla glue to set.
5. paper tubes for servo wires installed.
6. The width of yardstick would make spar to thin for desired profile. I added about 1/4 inch to the spar for proper profile thickness.
7. The right half of the wing is closed now.
8. Combination of clamps and two-by-four golding everything together till glue sets

draftman1

very nice. yes the 2mil isnt very ridged but I have never had a problem either. that is gona one awesom trainer.

RysiuM

My Feedback: (1)

Actually it is already, but about it later.

The wing got three servos: HS-225MG for ailerons and HX12K from HobbyCity for flaps. Flaps are moved by torque-rods (the same solution like ailerons in classic trainer). All horns are SPAD type from gutter pipe. Notice that coroplast is enforced with multiple bamboo sticks where horns are mounted.

Inside the fuselage three additional servos: Elevator and ruder (including front wheel) has HX12K each and throttle got HS-225MG. Servo trays are made of the same gutter pipe cut to fit.

Power is from Duralite 2500mAh 2s LiPo with 6V/10A voltage regulator. Radio is ASSAN full range (with dipole antenna) 8 channel receiver. This Spadet is going to be a test plane not only for ASP 60 but for ASSAN radio as well.

Now here are pictures:

1. The bottom part of the wing
2. This is how flaps will be moved
3. Ailerons
4. Elevator
5. Rudder
6. Servos inside the fuselage
7. No fuel tank and radio yet
8. And this is how it looks completed
9. Another view

Report from flying soom.

RysiuM

My Feedback: (1)

I took it to the field for the test flight. Nicely supprised I found ASSAN system performed very well. Despite the horrible stories about the Rx not working when put inside the fuselage or radio lockout when the other 2.4GHz Tx was close to the plane. I tested the range with my buddy standing with his Spectrum TX next to the plane and me walking away holding my Tx in front of me (meaning it was my body between TX and the plane). I had full control all the time. On the ground and in the air as well. So ASSAN passed my test.

ASP 60 was the tough guy to work with. Finally I figured out that on my fuel (Wildcat 15/18) it needs to run rich on the ground so it is OK in the air. But this guy is very expensive to run. WOT it burned 11 oz of fuel in less than 5 minutes. At half throttle it provides enough power to fly this plane normally burning about 1oz a minute. I was missing my gassers during that flight

Finally about the Spadet. It is awesome trainer. It flies exactly like Kadet LT-40. So easy to take off, fly and land. Not much to say - it is just a first class trainer.

The last test was trimming flaps. I setup two steps: about 20 degree and 45degree. The setup required just a bit down elevator when flaps were put to 20 degree. Moveing them down to 45 degree did not require additional elevator, but slowed down this trainer almost to the walking speed (at least it feels like it ). That makes landings very easy.

So in conclusion, Spadet is awesome trainer. It can survive bad landings (in my standard "crash test" I was droping it from 3 feet on the concrete floor) without damages - the worse thing that happens is a broken prop. If I can resolve the fuel-ssucking issu it will be my primary trainer for beginners.

MrGreenSpeed

Great build RysiuM [8D]

I put an OS 61-H (6H carb) on My ASP 60 and it cured the dead stick problems, for Me at least.
Hope You get the fuel problem solved, dead sticks suck. [:@]

Thanks for posting the build pics.
Jeff

RysiuM

My Feedback: (1)

With Perry and rich it works fine but 2oz per minute is just bummer. I just tried to run it on straight gasoline/oil mix (18% oil). This was kind of experiment from "Gas on glow plug" thread. When glow was lid the engine run just fine - of course with mixture setting way leaner than with methanol. It takes about 0.5oz per minute WOT. I guess I have a excuse for another experiment

MrGreenSpeed

Cool idea, I'll be watching for the results of Your experimenting.

Are You thinking about using an on board glow system or adding some methanol to keep the glow plug lit ?

Jeff [8D]

RysiuM

My Feedback: (1)

I have already tried 1:1 gas and methanol and it is still not good to keep the glow plug hot. Famous formula 2:1 works good on bigger engines, but this ASP is much smaller (only 10cc) and it needs more methanol to run without glow power.

I got all components to make on-board battery and gas fuel delivery, now I need to put all together. I hope the muffler preasure will keep steady fuel delivery or I will have to use fuel pump too.

RysiuM

My Feedback: (1)

Here are the measurments on the comparision between original glow setup and gasoline setup:

Wildcat glow fuel 15/18 (15% nitro, 18% oil) makes 11700rpm on MA 12x6. After few minutes of WOT static (on the ground) the head temperature stabilized at 298F. You may suspect that the mixture was to lean - no, it was at the point where opening needle made the engine slowing down significantly, but leaning the mixture did not make a change in rpm. This is as good at it gets.

91 oct gas with 20% synthetic oil makes 11500rpm on MA 12x6. After few minutes of WOT static (on the ground) the head temperature stabilized at 292F.

Now I can compare:

Rpm: 11700 glow, 11500 gas (gasoline makes 200 rpm less)
Temperature: 298F glow, 292 gas (gasoline makes 6F less)
Glow power: not needed for glow, required all the time for gas.

RysiuM

My Feedback: (1)

I have finished converting this plane for gasoline-oil mixture with glow plug ignition. On the ground engine runs very reliable and stable. Needle is very sensitive but I hope the mixture will not change during the flight. The fuel is 5:1 - 91 oct gasoline (Chevron in California) and synthetic racing oil. I did not fly this setup yet so I don't know how it will run in the air.

Now pictures:

1. The engine. The dot on the left side of the plane (right on the picture) under the fuel filter is the fueling dot. Entire fuel installation is with tygon tubing.

2. You may notice new addition to the carb - velocity stack. I just made one - it works but there are still some spills on the plane. I'm sure the carb is leaking.

3. Glow plug powered during the flight. The setup is from some on-board glow system.

4. New switch on the left side for the glow plug. Battery was placed behind the "windscreen". O made a little shelf using scrap of gutter pipe. There is no charging jack for glow battery. The battery can be easy removed, disconnected and charged outside the plane while I can fly on spare battery. Both batteries are Sub-C one is 3300mAh, the other is 3700mAh - each good for one hour of flying time.

5. You can see the switch just above the gutter tube where the fuel tank is. An battery visible. At the bottom of the picture you can see ASSAN receiver (2.4GHz) wrapped in the foam. This is "full range" 8 channel receiver with external antenna (you can see the brass on the left side)

6. After I run the engine for some time there is a burned oil staining the whole side of the plane. It is also on the right landing gear and on the floor. Nothing strange - it is the same stain as form the glow fuel, just black instead of pink.

7. These are the stains. It is just oil, noting that indicates to high temperature. All gas planes have the same just 10 times less.

DLSmith2

Very slick! Looking forward to the flight report!

Anticipating any problems when it unloads once airborne?

SPAD skies,

DL

RysiuM

My Feedback: (1)

I flew it.

The needle is very sensitive but possible to set. The plane has the same power (if less, I did not feel that) as on glow. The only difference is, that it is very sensitive to the fuel delivery and even high-G turns changed the mixture. I tried to make a loop and on the way up the engine died.

The flying time is at least twice longer than on glow. This trainer flies well at half throttle, so I did time the flight at this conditions. No loops no rolls, just boring flying in circles. On glow fuel I had 8 minutes of flying time with 1/4 fuel left so I could get about 10 minutes. On gasoline at the same power setup I flew this trainer for 22 minutes till it died from fuel starvation.

If I want to fly this plane without any acrobatics, no even loops or rolls, the plane is very gentle to fly and the engine is running very reliable. The good thing is, that Spadet glides very well. No matter where I was when the engine died, I always managed to find a way back to the runway very easy and land with flaps fully extended. BTW it is fun to land this model deadstick - it teaches how to flare and land on the main wheels. If not landed on main wheels it will bounce 100% sure.

There are two issues for performance flying:
1. Needle is very sensitive to set and must be adjusted often as the air temperature changes during the day
2. Muffler pressure is not big enough to deliver steady amount of fuel to the engine. The best would be to have a fuel pup with pressure regulator.

Both issues can be solved by installing Walbro carburetor. I'm going to get a small carb for 18cc engine and that should work.

Oh, and one more thing. The engine can be started from flipping the prop. It did not want to start that way on glow.

DLSmith2

Thanks for the report! One more project for me to look at...[8D]

MrGreenSpeed

Great report RysiuM.
More than double the flight time on the same amount of fuel is an awesome result.
Using a small Walbro carb is a great idea and I hope it will solve the dead sticking during maneuvers problem.
Looking forward to seeing how You adapt a Walbro carb to a .60 engine.
Jeff

RysiuM

My Feedback: (1)

I have ordered 10 Walbro carbs varoius type small throat (7+mm). Waiting for delivery

MrGreenSpeed

Bin doing some research on walbro carbs.

http://www.geocities.com/farellus/idle_adaptation.html
http://www.youtube.com/watch?v=oTa_G...eature=related
http://www.rcuniverse.com/forum/m_14...tm.htm#1483989
http://www.aerocorsair.com/id28.htm
Jeff

RysiuM

My Feedback: (1)

Carbs arrived. From this box I picked up WT259 and afer replacing some parts using other models as a parts source I created something that fits the motor quite nice. This is how it looks like - not finished yet but getting closer.

RysiuM

My Feedback: (1)

After playing with different carburetors and different setups finally I got WT308 installed. I was able to tune it quite well for very reliable running, ticking idle and clean full power. Today I test flew the plane with new carburetor. The fuel is gas-oil mix that contains 6% Amsoil 100 (15:1 mix). No problem with loops and rolls. The engine runs very reliable.

Then I tested the flying endurance. This Spadet has only 11oz fuel tank which is quite undersized for 10cc (class 60) engine. I flew in circles (so boring flight) at 1/2 throttle for 23minutes 32 seconds not including startup, runup, taxi and take off. I think this is enough for simple trainer.

So I got my setup right. I still need to open the engine to verify that the mix has enough lubrication for this engine. The exhaust leaves the trail of brown oily smudge on the fuselage and horizontal stabilizer but it still looks like not burned oil. So I keep high hopes. For sure the fuselage is cleaner than when I was running glow fuel.