“New” 28% Wild Hare Extra 300 84”– Red Black Yellow

[FlyinTiger]

Now to shoehorn everything in to see how it fits! DA also said not to cut the stinger pipe if possible, but if I HAD to cut it that hacking off an inch wouldn't make that much difference. I can't wait to hear this baby running and compare it to the Slimline Pitts that i so fondly remember. The MTW-75 canister is a high volume muffler so it should be fairly quiet without robbing any power from the engine. I'll report RPM numbers after I get a few tanks through the newly rebuilt DA-50R.

[FlyinTiger]

Now to make templates and cut out the 1/16" balsa tunnel lining and install it.

I made cardboard templates so I could get that perfect fit right from the first cut of the balsa. Light weight balsa wood should do a great job sealing off the tunnel as there isn't a whole lot of pressure in the tunnel and the canister shouldn't ever get so hot as to char the balsa. The only place the canister could possibly touch wood is if it slips back the rear of the tunnel is only a 1/16" away...nice and close.

The measurements on the carbon templates should make it VERY easy to cut more templates if I build one of these babies again in the future (you can use them too). The overall goal is to make this canister installation EASY and predictable from the beginning. Maybe we could even get Tom to include these balsa pieces and the canister isolation mount laser cut from the factory for sealing off the canister tunnel and perfect alignment of the canister without cutting and measuring, then cutting again. The laser cut pieces could come in the canister kit he sells and cut down on the build time by a coulple of hours.

Only one template was needed for the side/ were perfect mirrors of one another. The top plate needed four little holes so I could mount the fuel tank in the original location. I am gambling that the canister won't ignite the "hook-and-loop" fastener that will be passing only a milimeter or two away due to the large volume of air that should be flowing through the tunnel. I'll get the heat gun (temp sensor) on it after some flights to monifor the heat dissipation.

[FlyinTiger]

I glued the tunnel sides in with medium CA by applying the glue then quickly placing the balsa piece in place. I did both sides first, fuelproofed the first half of the canister tunnel. I used thinned 5 minute epoxy so it should be fairly light. Once the sides had dried just enought not to be tacky I put the isolation mount in, then worked the canister in, twisted it so the "stinger" fell down into the hole I cut just behind the cowl ring.

Holding everything in place was difficult, but with a few tweaks we could have a much easier gasser that flies great and allows me to do it relatively quietly. I kept the canister mount in place so I could feed Velcro through a couple of holes I cut in the balsa top piece. A good dousing with thin CA was in order for the joints where the canister mount just went on. Once everything was aligned and glued on the inside I was able to secure the balsa on the tank tray. The four holes will still allow the Velcro to hold the fuel tank in place.

[FlyinTiger]

You can see the generous air duct exit. You know what they say, 1 to 3 if possible. One square inch intake with a three square inch outflow.

Good luck and please let me know if you have any questions!

[RustyTumbles]

Very neat job flying tiger. My canister install was slightly different as I have the older model extra. I did cut a small slot in the front former to fit the stinger in, I have not had any ill effects from this and the structure still seems very strong.

I think you will like to sound of the canister. It is very quiet when compared to the slimline pitts, and it has more power.

[FlyinTiger]

Rusty,

I can't wait to hear the purr of that canister...that means this baby is going to FLY! We'll make sure to get a link to the maiden video on the forum so people can hear the sound of the canister and Wild Hare 22x8 prop.

Let 'r rip!

[FlyinTiger]

Well, I've been doing the "other half" of many projects that have been covered here in this build review. The other wing servo, sealing the aileron hinges and building my wife a foamy, so now I'm back into the postable stuff! Don't worry, I won't leave anything out, it is just that no one wants to see pictures of the other aileron servo being mounted and the linkage being done if it has already been covered on one side...right?

So, here's the prop balancing technique that I like to use. I picked it up from a respected giant scale builder and pilot from the East Coast. This method differs from the widely accepted "DOD" method in that there is no externally mounted weights (velcro soaked in CA). The external weight could come loose, looks terrible (for my fellow obsessive builders) and has the potential to get CA on other parts of the prop...not to mention the amount of CA fumes that are produced from that much CA!

Here's the steps I followed for a perfectly balanced prop, tips to the hub:

1. I bought a suitable balancing device. I could have borrowed this item if I knew someone who had a balancer, especially since there will only be two props balanced for this plane (the break-in prop and the running prop). I chose the Dubro balancer because of its multi-functionality.

2. I drilled the prop bolt holes earlier in this review, but that is the first step to getting a good solid fit for the prop on the hub and with the spinner. Always drill the bolt holes before messing with anything else on the prop.

3. I balanced the tips of the prop first by placing the prop on the balancer and pointing the tips at the 3 and 9 o'clock positions. I made sure to turn the prop over and check both ways to eliminate the possibility of the hub being drilled off center (a guy had this problem recently).

a. If there is a heavy tip it will drop to one side. The heavy side can be left alone, but add some clear dope to the light side to make the prop balance perfectly at the 3 and 9 o'clock position.

b. Check the prop after the dope has dried for about ten minutes. As the dope dries it evaporates off some of its mass and is lighter when dry. Apply only a little at a time to avoid making that side heavier.

4. Now that the tips are balance the hub can be balanced. I put the tips at the 11 o'clock and 5 o'clock position. The prop won't move if the hub is perfectly balanced.

a. If the prop does move it will rotate so the heavy part of the hub is toward the floor. Check the prop in all different orientations at the 11 and 5 positon then the 1 and 7 position.

b. Stop the prop from rotating at several points along the path of rotation to see if it will stop there. If it does stop before the tips are horizontal the heaviest part of the hub is still at the bottom most point of the hub. This gives me an idea of where to put the weight that I am going to put inside the prop for proper blance. I put a small mark on the opposite side of the heavy point of the hub.

c. I drilled a hole 3/8" deep and the same diameter as the solder I am going to use as my weight. I made sure that the hole would be behind where the spinner backplate would contact the prop hub. This hole will be plenty deep and won't weaken the prop at all.

d. I cut a piece of solder with side cutters as long as the hole was deep. This gave me an idea of whether or not I had enough weight. I inserted the weight part way and then put the prop back on the balancer. The prop hub was now too heavy on the side of the weight, so I slowly snipped off a little piece and retested the blade. As entertaining as it was, I am glad I finally got to the point of balancing the propeller in all orientations (11 and 5, 1 and 7, anywhere the prop should stay put).

e. When the prop balanced perfectly I simply pressed the solder down into the prop so it was flush with the rear of the prop. The solder fit tight and also the spinner backplate will be there to make sure the weight can't come out.

[FlyinTiger]

I'm back with the throttle and choke servo "tray" installation. I can see this position for the throttle working on any rear carbureted engine, side carbureted, even front carbed motors! Using the same sized pice of plywood I could have moved the tray to the other side. Now that I have measured all the parts that need to be fit for the servo tray I decided to make a carboard "trial fit" piece so I would only have to cut the plywood once.

I even cut out the servo holes so I could place the cardboard piece into the fuselage to double check that pushrods would line up. It was simple to line everything up perfectly using the cardboard method.

[FlyinTiger]

I cut out the servo tray with a sharp Xacto knife. It was slow and painful, but made for a nice clean edge. I split the two servo cutouts in half to make doublers for the back of the tray where the servo screws were going through. A doubler makes me more comfortable about the servos being secure in the mount up near the front where the vibration is. Hopefully the doublers prevent any oscillations that the tray may have experienced while only one layer thick.

I added triangle stock to the top and bottom on both sides of the servo tray. Everything was glued with Extra Thick CA, which should hold at least as well as epoxy. Next I'll install the servos and make pushrods for the throttle and choke.

[FlyinTiger]

I took a break from the throttle and choke linkages to paint the fiberglass spinner I got from Esprit Models. After roughing it up a little with some 320 grit sandpaper I cleaned the dust off with a rag and rubbing alcohol. From there I proceeded to paint the spinner with Cub Yellow Ultracote. The paint matches the plane's covering perfectly and went on in three light coats without any trouble. It looks so nice I'm debating whether I should clear coat it or not. When I go to clear coat it I'll just lightly sand it with fine sandpaper, clean off the dust with a tack cloth, then spray the clear in two or three light coats.

Man, I really like these fiberglass spinners! Lightweight and easy to customize for a unique personal touch...nice on an ARF.

[RustyTumbles]

Looking good. Almost time to fly her...

[FlyinTiger]

YEAH BABY!!!

[FlyinTiger]

After the spinner was painted I decided to go ahead and finish up the throttle and choke linkage installation. In an effort to save as much weight in the nose of the aircraft as possible I'm trying out these rod ends from Troy Built Models ( www.troybuiltmodels.com ) that go over the outside of the carbon tube, they will never split! I like the titanium rod ends from Central Hobbies, but these looked like they were worth a try, plus black metal on carbon fiber looks nice.

IMPORTANT: clean the surface of the carbon fiber tube and the inside of the rod-end, then dry them before applying any glue. I used a regular paper towel to clean the CF tube ends, then used a cotton swab dipped in rubbing alcohol to clean the rod-ends.

After applying the JB weld and assembling the parts I noticed the rod-ends were trying to work their way off the tube. It appears that the air inside the CF tube was expanding and pushing off the ends. I had to put tape on the rod-ends to secure them so they didn't slip.

Once the JB weld was dry (approximately 12 hours) I installed the pushrods on the servo arms and the carburetor throttle and choke levers.

[FlyinTiger]

Next on the list is the fuel tank. Fuel tanks are quick and fairly easy to put together, but sometimes it just takes a while to get around to plumbing them. I chose to use the 3 line system to eliminate the use of a "T" inside the fuselage that a two line system would have. I have both types and it just depends on what mood I'm in as to which one I install. One line goes directly from the ceramic filter that acts as a clunk to the carburetor, split only by a brass tube with barbs on both ends and secured with tubing clamps. Another line goes from a pick-up tube in the bottom corner of the tank for filling and extracting fuel from the aircraft. Last and equally important is the vent line that will go down and out the bottom of the aircraft, but not before passing through a filter. The filter prevents dirt from entering the tank through the vent during ground maneuvering.

I used Dubro fuel line barbs on both ends of all the brass tubing to make sure that the Tygon doesn't slip off as it expands from being in contact with gasoline. I know now to solder the "other end" on after they are inserted through the gasoline safe stopper. Don't ask me why I mention that one...

I chose to use the Dubro 24 oz. tank that comes with the Wild Hare hardware kit, but a much smaller (i.e. 16 oz.) tank could be used. With my timer set at 15 minutes I still had almost 1/3 a tank of fuel left after landing. Realistically, one could get rid of that extra 8 oz. of fuel and fly for 12 minutes with a 3 minute reserve. One word of caution though...when flying IMAC there could be a time wher I take off and have to wait to start my sequence until someone else finishes. Two sequences are flown back to back so I would have to have enough fuel to feel comfortable staying in the air for all that time.

An alternative to using Dubro tanks, which some people have had split on them, spilling fuel throughout the aircraft, are Nalgene bottles. B & B Specialties www.bennettbuilt.com carries a wide variety of these bottles here www.bennettbuilt.com/page5.htm and they are very nice. My wife is using one on her gasoline helicopter and it has performed flawlessly in that demanding environment.

[FlyinTiger]

Since the canister tunnel blocked the fuel tank area from hosting the vent fitting I moved it back to under the radio tray. I had to add a piece of light ply to hold the fixture, but it worked out well. I made sure to mount it with enough strength that if I wanted to put a return line back to my gas jug that pushing a piece of tubing on the vent fitting wouldn't crack the wood. I used extra thick CA to glue in the plywood piece as well as the balsa triangle pieces.

Getting down in there to put the fuel tubing on the fitting was a MAJOR pain in the neck. My fingers aren't small enough to fit easily down in there below the radio tray. I heated up the tubing with a heat gun, then slowly worked it onto the fitting. That took patience! Speaking of fuel tubing, I tried a different brand this time on part of my fueling setup. Aerotrend Easy Flex gas fuel tubing might be better than Tygon...we'll see.

I bought "wrap around" Velcro at Michael's Craft store to strap down the fuel tank. The straps go into the canister tunnel, but it shouldn't ever get hot enough in there to bother them.

On a side note I went ahead and drilled out one of the center longerons for the antenna wire. I made sure to let the antenna exit a little "uphill" from the vent tube. When I'm fueling on the ground and a little gasoline comes out of the vent fitting I want it to stay out of the fuselage. Wicking up through a small hole, gasoline could soak into the wood inside the aircraft. I like to get the antenna outside of the fuselage near the receiver so I can eliminate any potential for interferrence. With Airwild Twisted extensions running down the top of the fuselage formers and the antenna outside on the bottom there should be no problems. I'll hold the antenna straight back with rubber bands from the tailwheel.