flyn2high

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Here are a few shots of the assembled wing sections showing the stars and bars.

flyn2high

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I use a small cheap siphon feed sprayer by Badger for the markings. It is great for small stuff and very quick to clean. No problem with lacquer based paints and thinners.

flyn2high

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The last painted detail is the strip on the fin.

flyn2high

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I am all finished wiring. Below is a photo of the inside of the fuselage. I had planned to use a Dubro 50 oz tank but it was a bit too high to fit. I ended up with a pair of 24 oz tanks that are connected in series. One is connected to the engine and fill port and the vent is connected to the clunk of the second tank. I made dummy exhaust pipes for the lower four exhaust ports. One of the pipes is the overflow / vent for the fuel.

The receiver is a Spektrum 12 channel power safe unit connected to two 2,500 mah A123 batteries. You can see the blue battery covers just in front of the fuel tank on the left side. I have two more batteries for the ignition on the left.
The Moki ignition module does not want to have anything over 6 vdc so I am using a Formeco regulator set for 6 vdc. In my experience with the Moki engine the higher the voltage the stronger the spark and the less chance for missing and rough running with the radial.

The small blue unit just to the right of the receiver is an iGyro. This is a 3 axis gyro and provides normal and heading hold to the ailerons, elevators and rudder. I had considered using the JR G370A gyros which mate up with my DX18 transmitter very well. The thing I did not like with the JR gyro is that for the ailerons and elevators I have them each on two separate servos and channels. I would have to use a “Y” connector on each into the gyro. I feel that it is a big advantage to have the redundancy of separate channels for the two most important control surfaces. The iGyro had two ports for the ailerons and two more for the elevator with one for the rudder. The second reason is that using 3 of the JR gyros would require 3 additional channels for gain control. In the iGyro one channel is used for the mode switch and the gain is set using a spare channel but after you are happy with the setting it can be disconnected and used for something else.

flyn2high

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I felt that I needed a little more detail in my sparse cockpit. A prominent feature is the gunsite. I drew it up in Solidworks and planned to machine it in sections out of plastic. After looking at it I thought this would be a good candidate for 3D printing. I contacted a local 3D print service called Shapeways and submitted the file on-line. To my surprise it was only about $7.50 for the part plus shipping.

Below is an image from Solidworks. I should have it in a week and then I will hard mount the canopy and canopy frame to the fuselage.

flyn2high

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Last night I had it all together for the first time to show off at our club meeting. I was able to transport it in my trailer on its wheels with the wing tips removed. I still need to balance it but when I weighed it with a luggage scale it was just about in the right place. I will have to do some careful setup by hanging it with the wheels up to get it right on. Total weight is 57 lbs. dry.

My next milestone is to start the engine.

grosbeak

Beautiful!

OldScaleGuy

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Great job!!!

mrwad

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Nice work !

stevegauth30

Work of art.

flyn2high

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Thanks

I checked the balance of the hellcat by hanging it in my garage. Once you make it level the CG is at the point where it is suspended. I made a small plumb bob to project down to the top of the fuselage to my mark.
Is was just about right on with the wheels down but it moved back 3/8" with the wheels up where the balance should be set. I only need to add 1.4 lbs of lead shot to the front of the cowl to bring it in.

stevegauth30

That's one impressive looking hellcat.!when do you plan to maiden it?

flyn2high

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Tomorrow is our club warbird fun fly and I plan to run the engine for the first time and maybe taxi it around a bit. I’ll be checking the temps and the reliable operation of the engine very closely. I put baffles in between the cylinders. Hopefully that will keep them nice and cool. I also want to look at the log information for the remote Spektrum antennas.

I still need to install the nose weight. That will be easy but I have to pull the cowl. I plan to mix up lead shot with epoxy and fill the inside rim of the cowl with it. There really is not that much. Maybe about a 1/4" of it all the way around the inside of the cowl. I also need to secure the hinges for the elevator. I used 1/16" music wire hinges. What my plan is to take a long 4-40 set screw and drill out the end (opposite the socket) to fit the wire. Hysol the wire in the set screw hole and then tap and thread it in the elevator. This way I can remove it if necessary.

After that I'll just wait for a perfect day.

I am planning to bring it to Warbirds over Delaware. Hopefully by then I should have a few flights on it.

stevegauth30

Yeah, our warbird event is tomorrow, and I had hoped to maiden mine before now, but hasn't happened. Oh well, at least I'll have a brand new warbird to display.

flyn2high

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The engine run up went well. The three upper cylinders were running at 220 deg F and bottom one and the lower right one was only 170. I was using a 40:1 oil mixture which is high but I wanted to use more oil for the first few runs. I had the prop set for 17 �” pitch. I understand now that this is probably a bit much as others have had issues with too much speed on landing. Anyway I was getting 3,800 rpm on the ground which is considered good. I now have it set for 15 deg. The cool cylinders are not firing at low rpm. This is somewhat normal due to the high oil content. At higher rpm it smooth’s out nicely.

When I got it home I found that the lowest cylinder’s plug as quite wet with oil.

Attached is a photo of the black oil that comes out. On my other Moki 215 this went away after about 10 flights.

flyn2high

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Here is a short video of the planes at the event. We had a great turnout and a fantastic day. My Hellcat is at the far end on the right along with my CARF Spitfire MK9 two plans away.

https://www.youtube.com/watch?v=Wwqiliulws4

flyn2high

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Its officially an airplane. Today I took it out for a its first flight. The engine was running on 4 cylinders to start but at the end I was lucky if I had two going. All that break or the very rich carb setting must have fouled the plugs. I checked the temps after it landed and it wasn't over heating. The engine calls for 30:1 oil to gas mix. I did 40:1 knowing that it would be too much. I will check to see if I am doing something wrong. It might have to break in better for more reliable runs.

After trimming it flew really well. I set about 5 clicks of down trim before take off and it needed a few more to level off. The ailerons needed a lot of right trim to fly straight and level. After that it was very nice to fly. I had my hands full as the engine was going slower and slower. At the end I was full power and it was coming down. I never had a chance to test out the flaps.

Sorry about the captions. Some how Youtube moved them forward.

https://www.youtube.com/watch?v=8qH-b-3ICgg&feature=youtu.be

Scott Prossen

Congrats Lou! I use 50:1 Amsoil in all my Moki's and never a problem. Been very happy and they all run great. On my Wildcat about the same size and weight of your Hellcat I'm running a Solo 3 blade and have set the pitch so as to top out on the ground at about 3500RPM. They have tons of torque and live long at lower rpm set with high pitch. Probably unload another 1000 rpm in the air and that's okay.

Clean your plugs, go fly and have fun. That's one hell of nice plane you've created there. Congrats again!

All the best,
Scott Prossen

stevegauth30

Congrats for sure. That's one heck of plane you built. A real beauty.

flyn2high

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Thanks Guys.

My problem turned out to be a bad ignition module.

Dave Wigley and I ran the engine and tried to tune the carb today. I did change to 50:1 oil mixture. After it ran for a few minutes It sounded like someone was turning the ignition on and off quickly. Then it sounded like it was off longer then it was on until it quit. Each time we started it was doing that sooner and sooner. It would run smooth at idle and as soon as you increased the rpm it was like rum rum rum. It almost sounded like a couple of cylinders were missing but the temps were all good. I tried everything including with and without the pump but there was no difference.

I ended up taking the ignition module off my Stearman with the Moki 215 and installing it on the Hellcat. Boy what a difference. I was able to set the top end and idle for nice smooth operation. I am ordering one of Voglesang’s high voltage ignition modules. For the time being I think I will be fine with the Stearman ignition until it arrives. i think the warranty is a bit old even though I just ran it for the first time last week. It's been about 5 years since i ordered it from Al's Hobbies.

I’m very lucky I landed when I did. The engine was just about to quit. I was full throttle coming around on final and it was just barely running.

Chad Veich

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A superb accomplishment Lou, absolutely stunning. Really looking forward to some more flight video once you get the gremlins worked out of the Moki. You can never have too many Hellcats as far as I'm concerned!

flyn2high

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Thanks I looking forward to flying it and getting the iGyro zeroed in. It should fly like it is on rails with the gyro.

flyn2high

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I had a very successful second flight today with the Hellcat. Sorry no video this time. I am using my old ignition module from my Moki 215 out of my Balsa USA Stearman and the engine is running really sweet. I have a new high voltage Moki module on order. The prop set for 15” of pitch and am using 50:1 mix of Bell-ray MC1 synthetic oil. The carbs needle valves are set of optimum performance with good acceleration. The exhaust still has black residue but a lot less than my first flight. I was able to test out the flaps with the gear down. Half flap had no noticeable effect on pitch. At full flap I only needed to add two clicks of down elevator which I later programed into my flap system on the DX18 I used up nearly the full length of the runway to land because I came in a bit high but I greased it in without bouncing.

Future flights will be with the iGyro 3 axis turned on. I ran out of channels to set the gain in the air so I am adjusting it manually on the ground and then I will use the 3 position mode switch in the air. Initially I set it up with 0, 25% and 50% gain. Past experience with a warbird I found I needed 75% and up for the elevator and ailerons with nearly 100% on the rudder. If I set too much gain the control surface will osculate but I can always switch to the lower setting and then readjust on the ground. It will take a few flights to tweak it in. I think it will be better to use the lower gain settings then to have to switch it off because it is doing a chicken dance due to too much gan.

I actually have been flying with the iGyro controlling all three axis but at 0 gain so far. I basically flew it at half throttle for most of the flight. I briefly opened it up for a few seconds at one point. The built in GPS reported a max air speed of 111 mph.

Twistedteddy

I just read this whole build. Ive come to the conclusion that I want to be you when I grow up! Lol! Bada $$ plane and build thread thanx for sharing man. Hats off.

flyn2high

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I Just started a new project that should keep me busy for a few months. It is a standard 93" wingspan Ziroli Corsair using a brand new engine by DLA. It is a small Quad cylinder power plant that has 128 cc. I know you are thinking this is way too big but I will probably still need to add nose weight and it will turn a bigger more scale looking prop. The forum build is at http://www.rcuniverse.com/forum/gian...l#post11854348. Thanks to all for your interest.