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

[FlyinTiger]

Just trying to get the word out on the new and improved great entry-level gasser. Most people that I've run across are loyal to one or two forums...so, hopefully posting this in multiple forums will help them stay "faithful."

[FlyinTiger]

Painting the cross members that will show under the hatch seemed to be an important detail to making this plane look good. Now the lower cross members fade into the fuse as if they belong there.

[FlyinTiger]

Getting the servos nested in their holes was a small task and a revealing one. Tom mentions in his manual to check all servo mounting plates because they are a weak spot in the manufacturing process...he's right. I had one of the elevator servo mounting plates come completely out while I was trimming it...only a small dab of glue was on it. The plates are not an integral part of the airframe. Special care needs to be taken to make sure they are glued in and can handle the rigors of fast flight. Those large surfaces see the most force when flying smooth aerobatics at moderate to high aircraft speed.

I wicked thin CA around the other servo mount and then put a bead of medium around the edge to make a small fillet. I glued the servo mount back in with slow thick CA, wicked thin around the edges and then put a fillet around the outside to make sure it stays in.

[FlyinTiger]

Each of the holes in the fuselage was neatened up by taking a soldering iron and melting the edge of the covering down while making sure the hole was round. A handy way to get the holes sealed around the edges, I might add.

Now that the tail of the plane is pretty much done, I went ahead and mounted the elevator servos. I made sure to take the servo out after the holes were drilled and hardened the servo screw holes with thin CA. I wouldn't want a screw to pull out in flight! I securely soldered a 24" twisted heavy duty 18 gauge wire extension to the servo lead. Each wire was individually insulated with heat shrink tubing and then all three wires were pulled together with a final piece of heat shrink tubing. This ensures the leads can't pull apart and that I have the best connection possible between the extension and the servo wire...as close to zero loss as possible.

[FlyinTiger]

To seal the hinge gap I used some transparent clear plastic film I found in the back of the hobby shop...it was marked as "hinge gap sealer" and sold in two foot by two foot sheets for 98 cents. I thought I would give it a whirl. I bought two packages, so, worst case, I would be out $2. I cut the sealing film to fit the beveled surfaces that were exposed when I opened up the gap by fully deflecting the control surface.

A one inch by eleven (plus a little) inch piece was used on the top and bottom of each elevator gap to make a nicely sealed hinge area. To keep the hinges from crinkling the film I cut small holes where each hinge was so the film would stay folded right down in the crevice as the beveled surfaces came together.

Now I won't have to worry as much about elevator flutter or control effectiveness, it is all taken care of (as long as that sealing film stays stuck).

[FlyinTiger]

Installing the surface control horns is a rather arduous task, just like most of the finishing jobs with any aircraft. I chose to leave the top covering in tact and drill the hole, then screw in the bolt to just under the covering. I used a 1/8 inch drill bit, not the 9/64 that Tom's instructions talk about, and took special care to clean out the sawdust every eighth inch or so as I was drilling the hole. By grinding the tip of the bolts to a 45 degree angle about half the diameter the bolt could freely cut threads in the hardwood. I screwed in the bolt then took it out to strengthen the threads in the hardwood block with thin CA.

I screwed the bolt back in, measured 1-1/4" from the center of the control surface and added 3/16" before cutting the bolt off. I am going to use 1-1/4" servo arms and I want a one-to-one ratio from the servo arm to the control horn. This gives me the needed clearance for the pushrod as the surface deflects on high (3D) rates, as well as the full torque rating from my DS 8611 servos. The 3/16" was added to compensate for the attachment nut for the pushrod that threads down onto the control horn. I want 1-1/4" from the center of the control surface to the center of the pushrod, not the top of the pushrod attachment nut.

To keep the hot piece of metal from burning my covering, I put some blue masking tape on around close by where I would be cutting. This prevented the sparks from burning the covering while I cut and kept the area clean too. It pealed right off when I was finished and went on the other side for cutting.

Perfect geometry is the key to perfectly matched elevator halves. I don't want to fight any crazy mixing, I've got my own learning curve to battle against.

[FlyinTiger]

Light, plenty of power, more than enough current and reliable as is necessary...nothing complicated here.

Duralite 6.0V Failsafe Switched Regulators - ignition, receiver, receiver
Never had a problem with these switched regulators. Duralite service is excellent. The two RX regs are matched at exactly 6.05V (read when attached to RX). Six volts is on the upper end of the range for DA, but runs the engine just fine and doesn't dissipate too much energy to heat.

TBM 2350mah Lithium Ion Batteries (3)
To slice right through the debate, it works. Great flying times...10 fifteen minute flights - easy on this battery setup, perfect for a long weekend of flying! Anything more and I would add weight. Each battery is only TWO cells...nice.

JR 945S PCM Dual Conversion RX
I decided if I was going to run only one receiver I would run the best that money could buy. Maybe that will be Spektrum next year, but right now it is dual conversion PCM.

DS 8611 servos for all flying surfaces
Why not supply the flying surfaces with as much torque as possible in a standard sized servo case? Ok, the case is a hare larger, but hey, it was worth the little bit of trimming I had to do. So far the metal gear JR digital servos have performed flawlessly over more than one hundred flights.

Hitec 5245 MG on throttle
Metal gears keep vibration issues from being a problem by stripping the gears on my throttle servo, digital gives me the same idle as well as the same throttle position throughout the range of my input and the mini size gives me plenty of options during mounting.

Hitec 225 MG on choke
The same size as the throttle servo but digital isn't needed on this little guy, but I stuck with the metal gears to combat that vibration. With well over 55 oz/in at 6V this little servo should be able to handle the choke actuation without a problem in the event that my throttle gets stuck and I need to shut down the motor in an emergency.

What better than some nice black self wrapping hook and loop fasteners to hold everything down over silicone rubber padding. I chose the 1/2" thick foam so I could smash it down a bit while tightening the fasteners and still have a 1/4" or so to isolate the electronics from any vibes that might make it back to the radio compartment.

As for the layout, we'll see if I have to move those batteries back, but for now they are in a fairly neutral place. The regulators were the furthest away from the switch mounting holes that Tom so graciously had drilled for us right behind the trailing edge of the wing. Everything should mount up with few flailing wires. Any loose wires I will secure with JTec fasteners or hot glue!

My receiver antenna is going to go straight down and out the fuselage, run along the bottom of the fuse and be held mildly taut with a properly sized rubber band or two. Notice: I taped in my RX crystal...HIGHLY RECOMMENDED!

[FlyinTiger]

Here we go again!

I cheated here...I had the old firewall. I carefully measured my previous Wild Hare to mark the throttle and choke pushrod access hole. To measure this passageway I initially made a smaller hole and worked outward little by little in the direction I needed to go for the pushrods to work freely. You can see that the cutout is generous, but even after over 100 flights the firewall didn't show any signs of cracking or flexing.

I made sure to put the DA-50R inside a protected box or bag while I was cutting and sanding since I didn't seal off the carburetor and exhaust. The last thing I wanted was to get dust inside a model motor that cost as much as a rebuilt Chevy shortblock V8.

[FlyinTiger]

Drilling the spinner back plate was a little tedious. My drill jig ( www.troybuiltmodels.com/Propeller.htm ) was a little tight fitting through the center hole in the Esprit spinner back plate and I didn't want to enlarge the hole. That center hole is what keeps the spinner centered on the crankshaft...the bolts just hold everything together.

The most important part of correctly drilling the back plate and prop is making sure one of the blades of the prop is at the 1 o'clock position with the piston coming up on compression. This will be the key to safely starting your gas motor without the fear of it backfiring or popping back on your hand. I don't use a glove and have never once had a problem with the prop doing anything but what I want it to. (Even my wife is comfortable hand propping it.) Starting the flipping at the 1 o'clock position and right before the compression stroke allows my hand to follow through naturally and with good force.

I used a drill press to make sure I got the holes drilled vertically square with the back plate. After lining up each hole with the drill jig and carefully drilling the hole, I placed a bolt in the hole to make double sure it stayed centered.

After drilling the back plate, I centered the prop between the splines that stick up to hold the spinner on and marked the prop. Using the drill jig I then drilled the prop from both sides.

This new line of Wild Hare R/C propellers looks promising! I chose to try the new 22x8 WH prop for the break-in of my DA-50R. The root of each prop blade is slightly wider than the NX prop of the same size. The prop is a full 22" in length and weighs XX ounces (XX grams). The clear coat is so shiny that I had trouble taking pictures of it...now all we need is a bunny on the blades!

[FlyinTiger]

Now that the firewall is cut for the pushrods and the hole for the fuel line to the carburetor, I went ahead and sealed the wood with thinned 5 min epoxy. Rubbing alcohol works great to thin out some epoxy so it can be brushed on with a throw away flux brush. I found that sometimes a gasoline engine will spray a little fuel out the intake of the carburetor when it is running a little rich and I didn't want my firewall soaking up that fuel during the engine break-in period when I will undoubtedly be starting the engine rich before it has a chance to be leaned out any.

For the final installation of the DA-50 I applied Blue (Medium) Loctite to the bolts to ensure vibration wouldn't loosen the standoffs. I chose to use hardened bolts with a hex head to fasten the motor to the firewall. The allen head bolts were too hard to tighten enough for my liking, plus the hex head bolts have a wider footprint to apply even pressure to the fender washers I put on them. The key, I think, is to apply a generous amount of force but spread it out a little, that way the firewall will be as strong as can be for those Hare-y maneuvers and abuse I'll be sure to put the plane through (intentionally and by accident).

To get these bolts tight I used a rachet, a knuckle, two extensions and a 7/16" socket. The top bolts were tough to get to and required the knuckle. I am confident that the bolts are tight and will hold!

[FlyinTiger]

Time to get the spinner a little closer to being finished. Cutting the spinner to clear the prop can be a little intimidating so I read the directions on the Esprit Model website to gain a little understanding. http://file.espritmodel.com/document...nner_cutt.html

It was easy to get both cutouts the same using the cardboard pattern technique. To make sure the pattern was placed exactly the same on both sides I drilled one hole in the carboard so it could be lined up on the spinner with one bolt through it for that perfect placement.

I had to leave a little extra room in some places around the prop to make sure I could get the spinner on and off, but there was no unsightly large gaps that sometimes are a byproduct of a precut spinner. Starting with the cutting wheel on a dremmel I made the initial rough cut. Fine tuning with a sanding drum on the dremmel, then a cutting bit for the corners I was able to make quick work of the cutouts. A little final sanding after a trial fit and I was done.

Look for coverage on the painting of the spinner Cub Yellow to match the yellow stripes on the Wild Hare Extra 300's fuselage in a future post. I love fiberglass spinners!

[FlyinTiger]

'Cause it had to be done, I went ahead and put the switch mount and charge jacks into their places. I chose to go ahead and use part of the precut switch cutouts that Tom designed into the fuselage on the 84" Extra. Each battery has its own regulated switch mounted with Dubro switch/charge jacks behind the wing and the ignition regulated switch is in front on the pilot's right just behind the motorbox and cowling.

All I had to do was cut out the covering where the mount would be protruding into the fuselage on one side of the hole, then drill a hole for the switch slider. I hardened the hole and surrounding balsa with thin CA then installed my switch/mount assembly. The "OFF" position is "IN" so if I (or someone else) were to bump the switch in transit it will stay "OFF" instead of turning on and depleting my battery's charge...very bad for Li-Ion batteries to go below their minimum voltage.

Well, I'd better stop posting and get back to work...I want to fly this baby soon! The weather is PERFECT out here in CA...75F and CALM! That will change soon...

[RustyTumbles]

Looking very good. You are doing an awesome job with this thread. Lots of good info and very good descriptions of what you have done and why.

Did you add any more right thrust to the engine when you installed it? I had to add quite a bit to my extra.

[gavo]

Very thorough job, I am slowly putting an 84" edge together and find your build very informative. I am a bit concerned about the covering on mine and was wondering what the "trim solvent" was that you used to seal the trim?

[RustyTumbles]

	Quote: Originally Posted by gavo
	Very thorough job, I am slowly putting an 84" edge together and find your build very informative. I am a bit concerned about the covering on mine and was wondering what the "trim solvent" was that you used to seal the trim?

G'day gav,

I have used clear nail polish before with great success. My wife has always got some laying around. Just apply a light coat where the covering wraps around corners. I only use it where the seams are not visible. On visible seam I just use the iron.