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Wednesday, December 10, 2014

60" Extra EXP__Just Like Old Times

Some of you may have noticed that I am a bit weird for Extras. I freely admit to this because for one thing it's  true, and for another it's so obvious that there is little point in trying to hide it! I've had many different Extras, both in size and brand, and the one thing they all seem to have in common is that they have a very good performance balance. By that I mean they do 3D and precision with nearly equal ability, and the EXP series has raised the performance bar in both respects.

So far I have had only one 60" Extra, but it was such a great airplane that I got nearly two years of hard service out of it. Two years might not seem like a lot until you remember I am in Florida, and fly nearly every day. If you fly four packs a day you can rack up 100 flights in less than a month, and that's the kind of treatment this plane got, and off, for about two years. I tried to count the flights on this plane, but lost track somewhere around 500 and gave up. I have no idea where I ended up with that plane, but it's still racking up flights in the hands of a friend that I passed it on to.

I flew my first 60" Extra extensively when we were testing the 4016/500 MkII prototype motors and I developed a very special bond with it. Because I had to run the motor hard for long periods, I used that as an opportunity to work on my high speed precision game, with lots of slow and point rolls.  My precision game had been badly neglected and was suffering, so this was just the shot it needed. I've still got a very long way to go, but the 60" Extra's precision nature spurred me on to improve my own. The Extra is the most precise flying plane in the EXP lineup, so it's the ideal pick for tightening up your precision game

I did not build my first 60" Extra, and the elevator was hinged a bit too tight. I got it loosened up a little, but all I could get was about 55 degrees. Performance was really good, but I wanted more pitch authority. It was always in the back of my mind that I would build another one and get more throw out of it.

Again, I went with the red/white/blue version. I thought about getting a red/black Extra,  but r/w/b  really suits the patriotic theme, plus it really lends itself to being turned into another Team America project. As of this writing I have not decided on any graphics, but I may just put a flag on the nose and be done at that. This scheme is so pretty I hate to clutter it up with sponsor decals. I might not even put the stars on it. This is a fairly busy scheme, but it still manages to be clean looking. I hate to ruin that with any unnecessary decals. I'll find a place to put some discreet Thunder Power signage, but mostly I want the plane to look clean and fresh.

The Kit
Like the entire EXP range, everything you need outside of the prop and spinner, radio,  power system and servos are in the box. These kits are very comprehensively complete.

I spent about 30 minutes sealing down a few loose edges and a wrinkle here and there, but for the most part it was a perfect covering job. The 48" planes are turned out really, really well, but the 60s" seem to be a notch better on the quality scale. It always amazes me that these planes are nicer than what we used to build by hand.

As of this writing I still have to rob the power system out of my stricken 60 Yak,  install it in the Extra and mount the cowling, but that's only about an hour's work.

As you can seem this is a striking design. I just love the long, streamlines look of the Extras, especially the EXPs.  With the EXP treatment of stretching the plane out, the Extra's long and flowing lines become even more swoopy and sexy.

Yeah. That's right. I'm a little weird for Extras.
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Just for now I shot some glamor photos without the SFGs. Of course, I am a big fan of how SFGs increase performance, but at least aesthetically without them the Extra really looks like an Extra. I'll have them on the plane when I test it, bit I am, also going to try it without them down the road.
This turned out to be a really clean build., I didn't use a drop of debonder on the whole project except for around the control horns. I always put too much glue in there and it gooshes out when you jam the control horn in. From there I wipee it off and go back later to clean up what's left with good old Golden West Super Solvent. Mostly everything fit just beautifully and it was another EXP that was a pleasure to build.

Everything was the same on this kit as my first Extra, with an few small exceptions. The new kit has a beefier tailwheel steering arm. I noticed one of those came with my 60" Yak, too, and so far it's been perfect. My first Extra had a fiberglass tube inside the fuselage to house the carbon wing tube, but that is now changed to carbon. The fiberglass tubes inside the wings have also been upgraded to carbon, too. These are definitely expensive upgrades that will make a more durable and better flying plane, and Extreme Flight did this without passing the costs on to the customers. Sweet.

You will probably want to spend a little extra and get a color matched Pilot X figure just because they looks so good in the finished plane. Pilot X figures are nicely made and, critically, light weight. I usually glue mine right to the canopy frame rails toward the rear of the cockpit. Make sure you scrape the paint off the bottom of the pilot where it glues onto the rails so you get a good glue joint.

I used medium CA and simply glued the pilot to the canopy support rails. Make sure you scrape the glue off the bottom of the pilot where it will glue to the rails. Otherwise you might not get a good bond.

Something different for this project are the HS7245MH servos that Hitec Multiplex was kind enough to send me. I've been wanting to try some high voltage (HV) servos, and these are the current rage in this size class of planes. In fact, while Extreme Flight used to recommend the 5245MGs, they have updated their recommendation for all 60" EXPs to the 7245MG.

I have held off on trying these servos because they are a bit expensive compared to what I have been using. that, and I had a bunch of 5245MGs that were already paid for. When these showed up, I knew it was time to build another Extra. The additional torque and speed will come in handy since the Extra flies fast so well, and the better centering will compliment the plane's precision nature.

Motor Type: Coreless
Bearing Type: Dual Ball Bearings
Speed (6.0V/7.4V): 0.13/0.11
Torque oz./in. (6.0V/7.4V): 72 oz-in/89 oz-in
Torque kg./cm. (6.0V/7.4V): 5.2 kg-cm/6.4kg-cm
Size in Inches: 1.28 x 0.66 x 1.29
Size in Millimeters: 32.4 x 16.8 x 32.8
Weight oz.: 1.20
Weight g.: 34.0
Of course, the previously recommended 5245MG servos will still work well for most people, but if you want the most extreme performance available, you will need to go to 7.4 volt servos. Just because something better comes out doesn't mean what's been working will automatically stop. I still have 5245MGs in my 60" MXS, Yak and Edge, and they are all performing fine. As of this writing, it remains to be seen how much of an improvement the 7245MH will be, but from what others are telling me, it will be substantial.
I am starting to deviate from the manual a little on this plane, but I've already had one and know what I want to improve, Mostly I am dead on with the manual except I went for every bit of elevator travel I could steal. I love my first Extra, but always wished I could get more elevator. This time I really watched my hinging and made sure I got everything there was to get while keeping the gap as small as possible. I've hinged so many planes I am almost starting to get good at it!
From there I believe it is absolutely critical to seal your hinge gaps. I suspect some people get tired of hearing me say it, but I believe it's that important. Gap sealing has it's greatest effect on slow speed control response, so to me that just screams "Ultimate 3D tweek!" Sealing also reduces the chances of high speed flutter, and believe me, this Extra is going to spend a lot of time going very, very fast. 
Servo Arms
Something different this time will be the Hitec PN55709 servo arm pack. Previously we used another brand, but quality on those became spotty and they developed a tendency to get sloppy and be able to wiggle back and forth on the servo output shaft. The splines on the servo arm would spread out, and trimming the plane became nearly impossible. I used Hitec's PN55709 arms when I rebuilt my 64" MXS and later when building my new 60 Edge and Yaks. These have held up really well, and they just happened to be the exact same size as the other arms. Nothing changed here except the servo arms fit tighter on the servos, which makes the plane fly much more precisely. We are spending a lot of money to build precise flying planes, so you have to pay attention to details like this.
Aileron Set Up
These linkages are similar to those found on the 48" EXP series except the bigger planes use a slightly beefier ball link. I like these a lot because you can really tighten down the bolt that secures them and that won't make the ball link stiffen up like happens with the smaller ball links. I put a lot of effort into getting the my ball links operating smoothly with no drag, so this saved me a lot of time.
As is customary on all my planes, I use Dubro 2mm hardened allen bolts and double nut all the ball links, then put a drop of thick CA on the exposed threads. Like this they will never come off on their own, but if I want to remove the ball link, I simply back off the outer nut and that will shatter the CA.
Here you can see that I used the outermost hole in the smallest servo arm that comes in the pack. With my end points set at 140%, this gives me about 32 degrees of aileron, which, believe me, is enough on this plane. I have flown a friend's Extra that had more throw and I could barely hang on to it. With this set up  it feels just a touch faster than just right, to me anyway.

Elevator set Up
Once again, we go for the gusto on the elevator. Using what I learned from my first 60" Extra, this time I was able to get 70 degrees of elevator throw! I used the longest double arm that comes in the Hitec PN55709 pack and cut one arm off. Like this you get the equivalent of one more hole to move the ball link out to. I hinged the elevator with a reasonably tight gap and was still able to get that much. Even if I had a longer arm I don't think there's anything left. It's almost bevel to bevel.

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Rudder set up
Again, we use the longest arm from the pack. Since the Extra is so stable with it's long tail moment, you want all the throw you can get here. I generally get it to hit the elevator and then back it off a little with the endpoints. Using the outer hole in the arm was so much throw that I have to dial my end points back to around 100 or so. Instead, I went in one hole and maxxed out my endpoints.

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Power System
Once again, I went with the powerful and reliable 4016/500 MkII motor and Airboss 80 Elite ESC. Everything drops right in with no hassle.

I run this power system in all my 60" planes. I get solid reliability, which is paramount when you rely on the power system so much in post stall maneuvers. If the power system fails in a low level hover or harrier, your odds just got real long. I've been flying Torque and Airboss exclusively for over six years now, simply because I can't afford to use anything less.

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Something a little different this time is that we need to bump the voltage to the servos up to 7.4 volts. Some guys use a 2s lipo and some guys use a different 7.4 capable ESC. Wanting to stay with the Airboss, for now at least, means I need to run a separate BEC. I chose the 10 amp Castle BEC which you can program on your PC with the Castle USB Link.

With the industry set to go to 7.4 volts on high performance aircraft, I am hoping to see a 7.4 volt Airboss on the market soon. That would certainly solve a lot of problems for me.

Here I did my best to make a clean and clutter free installation, but to me that's just a bunch of unnecessary spaghetti. I much prefer the BEC to be on the ESC to keep things tidy. This is not really so bad except I was probably just being obsessive.

As you can see, I soldered two deans plugs together back-to back and soldered the BEC lead to that. The ESC plugs into one and the batter in the other. I don't really like using separate BECs because the solder joints are another  potential failure point. This is made even worse by my soldering not being the best.

Mostly I am just spoiled by Airboss ESCs. There's no soldering or programming or anything. You take it out of the package and it just works. Dinking around with the separate BEC with the extra wires and soldering was a pain in the butt and I hate it. I sure hope we get a 7.5 volt Airboss ESC soon.

Battery Placement
as always, Thunder power batteries. The last year I have been running 6s 3300 Pro force 70C packs and have been really pleased with them. With the battery where you see it, CG sits right about on the middle of the wing tube,l so I will fly it and see which way it wants to go. If I remember correctly, I liked my last extra right on the front of the tube, but that was two years ago and I fly differently. I might want to go forward and I might want to go back. I just have to fly it and see.

(Note: I took this photo before I had my BEC installation finalized.)

I am hoping to shoot some video later today, and I will either tack it on here or do another blog post. I've already extensively flown one of these for two years, so I don't expect any surprises except maybe I'm going to like this plane better because of the increased elevator travel. This one is also a little lighter because I dropped down from Thunder Power 6s 3850 Pro Power 65C packs to 5s 3300 70C Pro force batteries. I also went to a little more effort to watch the weight I put on it, so I am hoping everything will add up to a big benefit and better flying plane.

Update: I had an eventless day with the new 60" Extra. No trim, no mixes and no surprises, just exactly what you want for an initial shakedown, and what I have come to expect from every EXP. That does not mean I take it for granted because I don't. These planes are so well engineered and built that I almost never have to sort one out. I was flying it hard right away and really liking the extra pitch authority. It might be a little too much and I will turn it down 10% next time I fly it. I had so much time on my previous Extra that I knew what to expect, but the faster and stronger performing servos require a little different style of flying. The planes is so much more responsive that you have to fly smoother. It's certainly not insurmountable. I went through that when I flew 7.4 volt servos in my 48" planes for the first time and figured it out pretty quickly.

I think I may have gotten used to a little bit of stalling with the 5245MH and didn't realize it. At high speed the difference in responsiveness alone is worth the price of the servos. From what I can see so far, I'm going to like them a lot. This could get expensive because I've got three other 60s I will probably want to convert. We didn't shoot any video or take any stills or anything. The first flight was so good that I just wanted to enjoy the plane and the day. We'll get some video later in the week, and I'll put it on a new blog post so subscribers will see it first.

I'm really glad to have gotten another one of these 60" Extra EXPs. I've really missed having one.

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