Laser EXP__The Spoileron Files

 

 3D flying has morphed into something completely different, though not necessarily new. The earliest 3D I saw was just a bunch of hovering around, but as pilots progressed and the planes improved, we started seeing the same planes performing high energy and precision maneuvers. Since in many of these maneuvers the wing is not stalled or partially stalled, this is not really 3D flight. Now we are into something else, but by combining high speed precision, high energy snap and tumble maneuvers and post stall 3D, we are really flying "Extreme Aerobatics."

As such, this means extracting as much performance out of the airframe as you can get. The elite manufacturers already make very capable planes, but even after they are done most extreme aerobatic pilots are still looking for more. This is why the servo debate and the power system debate rages on even after we already have amazing equipment. As hobbyists and tinkerers, this is simply part of our nature.

Spoileron and flaperon mixes are nothing new, but until recently they have not been considered essential on an aerobatic aircraft. It is the constantly evolving nature of extreme aerobatics that demanded we use them to get even more out of the aircraft, and this seemed like a really good challenge. It was also free and I would not have to build anything to try it!

The short version of the spoileron mix is this: The ailerons move up and down, coupled with the elevator and in the same direction as the elevator, but also remain independent enough that they can also act as ailerons. As the elevator goes up (or down), so do the trailing edges of the ailerons. This essentially under cambers the airfoil and causes it to create less lift. Since I am not an engineer, that's the best description you are going to get!

Set Up

With a modern computer radio this is easy to set up. I have not had a chance to set up a Spektrum yet, but on Futaba you just go to ele/flp mix, turn it on and assign it to a switch. There are times you won't want to use the mix, and this is why you put it on a switch. The mix improves some aspects of flight and hampers others and a switch allows to choose when to use it and when not to.

The default is 50% mix, but I found that to be too much for my purposes. Everyone is going to have to tinker with it and experiment with it for themselves, but I settled in at 25% for a lot of reasons I will explain a little later.

Of course, you have to run your ailerons on two different channels. If you are using a Y harness you can't make this work. I like separate channels because it allows me to sub trim the ailerons independent of each other and this makes set up much easier. Being able to use a spoileron mix is just a bonus.

Flying

 

Using a lot of spoileron mix can make the plane do some weird things, and in the beginning I simply used the switch to keep that from happening when I didn't want it to. Once or twice I got into trouble and barely fought my way out. The spoilerons kill (or spoil) lift, which is not what you need when you are fighting for your life!

 

The one incident that spooked me was trying to take off with a 50% spoileron mix. I had forgotten I had the mix on, and the plane was glued to the runway. I was taking off from the taxiway and crossing the runway, so I only had about 40 feet, and when the plane refused to lift up I drove it straight into the high grass. The plane covers that distance in about 2 seconds, so by the time I realized what I had done, I was simply screwed and had to ride it out. I ran off the runway and was lucky not to damage the plane, and it was not until a few years later that it occurred to me I was using too much mix for general flying.

 

So, I went into this hoping to find a happy medium. Naturally I wanted the mix to be effective, but I also wanted to turn it back a bit, with the goal of being able to use it for the entire time without having to flip it on and off all the time.

Laser EXP The Spoileron Files 001 from Doc Austin on Vimeo.

 

I found that 50% mix made takeoffs very long and difficult. It also made recovering from a stall take much more speed and power to the point that flying 3D you had to be extremely careful. Elevator drops were totally spectacular, though the plane would come down much faster because all the lift was being killed by the mix. Harrier was improved, but you had to carry the nose much higher and carry a lot more power because the plane was much more deeply stalled. In a parachute maneuver, the plane would rotate and then continue to fall at just about just about unabated speed.

 

This was all great fun, but you really had to stray on top of it. At 50% the mix simply worked too well. As time goes on I may or may not increase the mix as I become more adept at flying it, but for now I am using less.

 

 I wanted the plane to be a bit more docile and the mix to create more fun, so I started dialing it back, at first to 35% and that was still a bit much. I eventually settled on 25% because it felt good the first time I tried it. You could fly the plane and almost not even know it was on until you did an elevator drop or something. I could toss the plane around and fly out of trouble pretty easily, so that was the final piece I needed so I could leave the mix on.

 

Mix On

Once I started flying the plane at 25% mix, I just left it on all the time.  This way I could just fly the plane and not worry about if it was on or not. Instead of choosing when to use it, I just learned to use it for everything.

 

Elevator Drops

The most shocking thing the mix does is allow your to do an absolutely dead straight down elevator drop. You peg the elevator stick, stay off the ailerons and steer it with the rudder, and it looks like a spider dropping down it's own web, or a brick falling down an elevator shaft. With the reduced mix, the plane falls a little faster than with no mix, but you can easily arrest that with a bit of throttle. As far as what you do to fly this move, is really no different from not using the mix, except you have to carry more throttle nearer the ground (ground effect really sucks the plane in using the mix) and you have to be more overhead because the plane won't travel forward much. Most elevator drops are on a bit of an angle, but with the mix it is like it falls out of the air, only slower. This is simply good, safe fun. You start off high and if you get into trouble, punch out with throttle.

 

Harrier Flight

This is one of the most delightful parts of the mix. The mix will spoil lift, and now the plane will balloon less in a harrier. In fact, now when you pull the nose up the plane will sink instead, and this requires more throttle. With the lift on the wing being spoiled, it has to come from somewhere if you want to stay out of the ground, and all that's left is the power. This is where a good, smooth and tractable power system like the Torque and Airboss comes in.

 

For harrier you do not necessarily need to haul the nose way up there, but it is certainly easier and more fun. You will see in the videos how high I can carry the nose, and there is a little less danger of stalling the plane since it is already very nearly there anyway.

 

I also like to use a turning harrier to lose altitude and line the plane up for a maneuver at the same time. With the ability to use less throttle and have the plane drop more, it's easier to do this with more precision. I just had to adapt my flying style a bit and carry more throttle until I wanted it to drop.

 

Essentially harriers become more spectacular, but also, with the wing more deeply stalled, this reduces any wing rock you get from sloppy flying. The mix simply smoothes harrier flight out like a stick of hot butter. Hey, if it makes me look better it must be good, right?

 

Parachutes

Here we are going to start getting a bit scary. For a parachutes maneuver,  you dive straight down, gain some speed, and then hammer the elevator back. This rotates the plane so hard that it is like sticking your hand out the car window flat (fingers pointed into the wind) and then turning it up like a cop stopping traffic. The plane will jolt to a near stop, and if you hold the controls it will settle into a nice, falling elevator drop.

 

With the mix on, this becomes a little different. With plane stalling during the rotating, and with the ailerons pointed up, it simply stops flying without bleeding off a lot of speed. The plane will fall belly first at high speed. At first this was very unsettling, that is, until I learned that you absolutely have to get on the throttle almost instantly, and this slows the descent.

 

The plane has downward momentum, and if you are brave you use the momentum to get closer to the ground in a bigger hurry, and then use the throttle to slow the elevator to a sane enough speed to set it down on the ground. I have done a couple of these successfully, but since we are dealing with high speed pointed that the ground, this is a maneuver you don't want to get wrong and I have sort of backed off on it.

 

Most saner pilots won't experience this much fear simply because they won't cut it nearly so close. Best bet is to try this at a higher altitude the first few times so you can judge the sink rate for yourself. Then you can determine how hard you want to push it, if at all.This is not a deadly maneuver, but it will be if you get it wrong pushing it too hard. It's just different and very spectacular.

 

It also helps a lot to be running Hitec's awesome new HS5087MH (which is the high voltage digital equivalent of the HS85MG) on the elevator. This assures solid elevator response when you are asking for critical performance. A low level high speed parachute is not a good time to experience stalling or blowback, and this servo assures you won't.

 

Thanks to my friends at Hitec who provided the servos for this plane. It's this kind of assistance that makes it possible for me to do more projects like this.

 

 

Tumbles, KE Spins, Pop Tops And Such

I purposely used the MXS wing tips on this plane to give me a little more stability with the mix on. When I chose this, I was being a little cautions, and now it turns out the tips hamper tumbling somewhat. I put up with this because I liked the stability, but I will take them off for the next video shoot. I expect snapping and tumbling to be much improved, plus I will be able to get it into the car assembled again!

Laser EXP The Spoileron Files 002 from Doc Austin on Vimeo.

  

This is still a bit of a work in progress. This mix does not seem to affect the plane that much in positive (inside) snaps, but it definitely intensifies outside snap rolls. this shows up most in a pop top when the Laser will merrily spin around. I think for positive moves a flaperon mix would work much better, and I will eventually get around to trying that too. I just did not want to confuse myself while I was learning how to use a spoileron mix.

 

With the MXS tips the Laser is a bit more difficult to knife edge spin, but this disappeared with the spoileron mix. Now the plane KE spins like an Edge EXP. It is almost effortless. With the tips the entry is ia little more critical, and I use and outside snap roll to enter it with a little momentum. Like this it's just a matter of holding the sticks in the same position every time and the tail lobs over the noise beautifully. Full throttle KE spins are very hard on the entire package, so now I try to do them, with as little throttle as possible, and this works really well with this package. I imagine without the tips the KE spins will be even more ridiculous, though right now they are still as good as I have ever seen.

 

Hovering

I am probably not the right guy to talk much about hovering because I am not happy with my ability there, but the mix seems to give me more control in a hover. The plane seems to lock right in. I noticed this especially running the mix on my 60" Yak, but the Laser seems to benefit here as well.

Precision
I am not so sure about this just yet. In slow and point rolls I have a bit of trouble keeping the plane on a straight line, but it can be done. I think the spoileron mix changes the stick timing because when I flip the mix off everything here goes back to normal. I hit a few good slow rolls with the mix on, but can do it much better and more often with the mix off

Landing
The plane will fall faster if you are trying to bring it in way nose high, but outside of that the only difference I noticed is that the plane is easier to land in rough wind. The 60" EXPs are especially light on their winds and big gusts can make them balloon a little. The spoileron mix kills lift, so that helps settle the plane down a bit when you are flaring out. The 60s wheel land so nice that I prefer that on calm days, but when it's gusty the mix comes in handy when trying to set her down.

 

In General

For just flying around much does not change with this mix. I left it on for my point and slow rolls and it seems fine. The only time you need to be a little careful is at slow speed because any elevator movement makes the spoiler effect come on. This is simply an adjustment to your flying style, which is what the pilot is supposed to be for anyway.

 

For now this is something that is jolly good fun to play with. I will probably keep the mix on the transmitter but will go back to using the switch and choosing when I want it on .... when I can remember, that is. Since my current transmitter will allow me to choose only spoilerons or flaperons, but not both, I plan to shoot a couple more spoileron videos and then try the flaperon mix.

 

I am sure that will probably be a fun project too.

Nailed

OK, you probably knew a disclaimer would be coming, so here it is: The spoileron mix changes the way the plane flies. This is both a good thing, but a potentially tricky thing. For example, you will be blown away by how fast the airplane continues to fall after a parachute, maybe to the point that you stand there with your mouth, open watching it all the way to the ground.

 

Don't be that guy. When using the mix plan you maneuvers a little better, set them up better and definitely use more altitude. With a little time you will adjust your flying and sometimes even forget it is on.

 

Some people are going to like this mix and others will prefer not to run it. I didn't like it when I tried it a few years ago, but this time instead of trying to adapt my flying too much I adapted the mix to suit me. Start off at 10% mix and then turn it up until you don't like it, then turn it back to where you did.

 



60" Laser__Worth The Wait

Now it can be said: I waited too long to get a 60" Laser. I planned to build one all along, but other things kept getting in the way. Mostly it was a matter of funding and priorities. Just when it seemed like I would never get around to it, Hitec sent me some badass HS7245MH servos and made the project possible. So, here's a big thank you to my friends at Hitec.

De LaMoose
As chronicled in 60" Laser EXP__Finally, this is one moose of an airplane. It's just massive and immense in every sense of the word. For example, I transport all of my 60" EXPs across the back seat of my car, and that's with the rudder cocked so I can get the door shut. With the big Laser, this is not even an option because the thing is so much longer. I had to stand it up in the front seat, and even at that the rudder was only about an inch from the headliner. When I set it down next to the 48, it looks a hell of a lot larger than an extra foot of wingspan. This is such a big plane I almost titled the article "Laser EXP__Immense"!

Light Weight Flying Nature
This plays itself out nicely in the air in the form of more lift producing area. When you have the wing stalled in 3D flight, you have to fight and scratch for lift anywhere you can get it, and a big fuselage, canopy, cowl and monster SFGs really help here. Each new EXP seems to get a larger and larger fuselage, so you can see the evolution taking place.

The Laser rivals the Edge and Yak for being light on it's wings, and this gives it dead solid harrier manners. In fact, I almost group these three together as the same plane because they are so much alike in this respect. This light flying nature has sort of won me over and I am starting to prefer these 60" EXPs over my beloved 48s. Pragmatism keeps the 48s in the game, but outside of that, the 60" EXPs simply rule. If I had a big car, more money and plenty of storage space, all I would have would be 60" (and maybe even larger) EXPs. These 60" planes are simply another world of awesome.

Instant Gratification
Much like with the 60" Yak, my initial reaction when flying a Laser was "Come on. It can't be this good." I had flown a friend's Laser once and was sort of ready for it, but even now I am still not quite believing how solid this plane is. It's nice when you like a plane absolutely right away.

My confidence was off the scale once I checked my trims and landed to turn my trim sensitivity down (from 4 to 1). Then, at the lowest trim setting, it took a single notch of up trim and that was it. That's the equivalent of 1/4 of a click of trim! This is the straightest plane I have ever built, but then again, it nearly came out of the box this way.

Smooth, solid and reassuring, the big Laser was sending me all the right signals right from the start. I sort of knew what to expect from flying my friend's laser, and from experiencing the Yak's eerie stability. Initially I wanted to be careful because it was seemingly too easy. That's when you usually get bit, but like with the Yak, it is that easy.

Spoileron Note
Lately I have been experimenting with a 25% spoileron mix on my 48" Laser, and I tried it on the big one too. However, I wanted the initial 60" Laser videos to be strictly about the plane, so for the videos in the articles I switched them off. We are planning to do a spoileron article soon, so stay tuned.

Laser EXP TEST 004 from Doc Austin on Vimeo.

Speed
The big surprise was how fast this plane is. With all that fuselage area and corresponding drag, I figured the laser would be about the same speed as the Yak. Instead, the Laser seems to be about the same top speed as the Extra and MXS. It might have a lot of area, but it is a slick design.

Of course, this is certainly helped by using the torque 4016/500 motor. With a Xoar 16/7 wood propeller, I am getting close to 1900 watts. This equates out to 2.5469168901 horsepower (electrical)! Part of this is from the Torque being a badass motor, and the rest is from using Thunder Power 6s 3300 70C Pro Power batteries. These are not even the latest generation of TP packs, but they are still very potent.

Groovin'
 Speed always makes for better precision moves, and the Laser excels here, nearly to the point that it is as good as the Extra EXP. Much like the Extra, the Laser feels like it is locked into a big groove, or riding on a rail in the sky. A lot of this is due to the servos centering extremely well, but the big fuselage and flying surfaces make the plane want to plow straight ahead when at high speed. This is extremely useful for precision moves, and it takes a bunch of work load off the pilot when he is not having to correct the plane's path all the time.

Slow and point rolls are easy because the big fuselage provides a lot of side lift and the plane does not drop that much. For consecutive rolls, on low rate you peg the ailerons over and it's a simple sequence of tiny up and down inputs to keep her level and on track. Of course you have to have your low rate set up for that, and at full deflection I set the low rate up to give me three rolls in five seconds. This is only a few percentage points off what's in the manual, so your best bet is to always start there.

The precision game with this plane is very tight. It only gives up a little here to the Extra because with all the side area a strong crosswind effects it a bit more. This doesn't mean wind bothers the Laser much. It is actually quite solid in high winds, but the Extra flies a little heavier and thus penetrates better. I did my maiden in 10-15mph winds and it was absolutely no problem. In calm air the Laser stays right where you put it, though that's a bit of a rarity for me since I live on a peninsula.

 The Alpha Dog
Post stall provided a few surprises as well. Harrier flying with this plane is totally effortless. Most people agree that the Edge EXP is the king of harrier flight, but if the Laser gives up anything here I am not seeing it. Along the same lines, the Laser does a really sweet elevator drop maneuver, every bit as good as the Edge. With a 25% spoileron mix, it's just sick and almost unbelievable. When you see it on the video you are going to think I faked it somehow, but it's very definitely for real. I don't want to talk about the spoileron mix too much just yet because I am planning an article on it, but it's definitely worth trying.

Another nice surprise is that the Laser is the most solidly hovering plane I have ever flown. My hovers need to be better, but with the Laser they almost look really good. The first time I popped it up for a hover it was like "Are you kidding me?" Normally I don't even get around to trying a hover for a few flights on a new plane, but the harrier was so solid I just sort of pulled the nose up until she stopped and hung there. Very surprising, and most pleasing. I didn't even have to hold that much reverse aileron to counter motor torque, and when I run out of aileron control is when I usually bail.

Eerie Stability
Looking back on my initial flight with the 60" Yak, I cut the maiden short because I thought something was wrong with the plane. It was too easy, too solid and too locked in. I landed because I thought I didn't dial in enough throw or had too much expo ...... or something. It just didn't seem right. When I could not find anything wrong I just kept flying it until I realized the plane is so solid and stable that it had fooled me. In essence, it was too good to be true, and the harder I flew the plane the more it revealed how good it is.

Eerie stability. That's what the Yak has, and it sort of prepared me for what to expect from the laser. It was not such a shock because I was a little better prepared for it, but the Laser is still so smooth and surefooted that I ended the first few flights feeling like I left a lot on the table and could have flown it a lot harder. Now that we have the initial report finished, that's exactly the plan .... fly harder.

Confidence
This is the big thing with the Laser for me. I was confident with it almost instantly. Once I got it fine trimmed it was like any other plane that I had a lot of time with. I knew exactly what I had and what I could get away with, and this was only a minute or so into the maiden. I would try different moves and it would do exactly what I expected from it. In a lot of ways it is much like the 60" Extra, though lighter flying. Since the Extra is the standard by which I judge every plane, any comparison to it is definitely a compliment. After a bit of time the 48" Laser became almost interchangeable with my 48" Extras, at least in the amount of confidence and comfort I had flying them. It is still a little early with the 60" Laser, but I am sure before long it will be the same thing with this plane.

The nicest thing about the Laser for me is that it has a precision nature of the Extra and the float-like-a-bee nature of the Yak. Right now it seems a little bit too easy, but that usually goes away when you start pushing the plane harder and harder. What the Laser has done is simply move the limit a little higher.

Laser EXP TEST 005 from Doc Austin on Vimeo.

More On The  Hitec7245MH
This is my second set of Hitec HS7245MH servos and I am really pretty thrilled with them. I have been flying HS5245MGs on all my 60" planes right up until my newest Extra and was very pleased with those as well, but the 7245MH are in another league.

I now realize I was getting a little stalling with the 5245MGs at high speed because now am running less throw on my low aileron rates. I set that rate for three rolls in five seconds, which is about 27% of full throw. With the Extra and Laser I had to turn that down to 20% to get the same roll rate, so clearly the 5245s were a little overworked. Still, if they were stalling like that it is amazing I got nearly three years out of a set of them.

The higher torque of the 7245s show up best in high speed and high violence maneuvers. Walls and parachutes are completely different now in that they happen instantly. Tumbles are much more forceful because the servo moves so quickly, and when you demand it, to the extreme. There is no pause and no delay. When you ask something from these servos you get it right now.

 

Initially I was running these servos at 8.0 volts in my Extra EXP, but they were so fast that the plane seemed a little twitchy at high speed. I dialed that back to 7.4 and now they feel about right. I started the Laser out on 7.4 volts and am really happy with it like that. I have also done this with the Extra my 48" planes that are running Hitec HV servos. Since there is no hint of stalling and blowback, it is probably not necessary to push the servos any harder than that anyway. They are crazy fast on 7.4 anyway, so I am not giving up anything there either.

For precision work, a servo that centers better gives you a more precise flying plane. If the plane is climbing or diving when you go to start a slow roll, for example, now you have to do the maneuver and correct for a poor entry, which more than doubles your work. You end up chasing the plane through the entire maneuver and after two or three of those I am just too worn out enjoy the rest of the flight. It's too frustrating to have the plane do something other than you are telling it to do, but  good centering servos and a well trimmed airframe pretty much takes care of that.

When the plane starts off and says trimmed, that means it goes and stays where you put it, which makes nice precision maneuvers easy work, and the 7245MH are a definite improvement here. If these is any one reason these servos are worth it, this is it.

For post stall 3D flight, it seems about the same outside of the 7245's better centering. Super precise centering doesn't come into play as much in alpha because you are rarely at center and always making a correction or movement of some kind. Still, if the plane wanders off somewhere you are not telling it to go, that just makes the pilot's job even harder.  Even when centering is not at it's most critical, having the plane stay trimmed makes the plane do the work for you, and makes it easier for the pilot to put the plane where he wants it to go.

When the airplane is stalled or partially stalled and flying in alpha, you are not asking that much from the servos. It is only when you get into the high speeds with lots of airflow going over the controls that lots of torque becomes critical.

The big difference with the 7245MHs is that the plane flies better all the way around. These are expensive servos, but only because they are worth it. A set of 7245MH costs about the same as the entire airframe, but if you want to get the most out of it, you've got to have them.

We are not playing around any more. The Laser is a serious plane,  in a fun sort of way, that is. It deserves the best servos you can jam in it and these are it.

Not Quite The Last Gasp For the 5245MG
None of this means that the 5245MGs are now inadequate. They just are not as good as the best. For sport flying and sport 3D, they perform well, and reliably too. It is only in inch perfect precision and white knuckle extreme aerobatic flying that they begin to suffer a little.

I still have sets of 5245MGs in my 60" Edge and Yak, and those will probably remain there because they are paid for and working well. Of course, I am so pleased with the 7245s that I can't see spending the money on anything else. Spending more hurts, but only until you get them in the air.

60" Laser EXP__Finally

As much fun as I had with the Laser Sport and Laser HV projects, the next step would most naturally be the 60" Laser. Both the previous projects were in the yellow/white/blue/silver scheme instead of the usual Leo Loudenslager inspired Budweiser-style livery. The scheme is so attractive that I decided to continue that theme on my 60" Laser.

For a lot of reasons I have been unable to put a 60" Laser together until now. Part of that was available finances, but also the 60" Yak came out this year. I wanted to replace my beloved 60" Extra, so all of that soaked up the funding. Along with my 64" MXS, there is just nowhere to store one more larger plane in my small house. As it is, the new Laser is going to have to live on the floor in the gym until I destroy something else to make room for it!

I did get a chance to fly my friend Rob's Laser early last spring and loved it, but you can't really fly your friend's plane hard enough get a good assessment....not if you want to keep your friends, that is! Still, I liked the plane right away.

Looking back, it was my first experience with the kind of eerie stability the Laser shares with the 60" Yak. It's so smooth, solid and easy that it just doesn't seem right. Anything that seems so right and feels so good is usually a trap, right? At the time I thought it was odd, until I got my Yak and it felt the same way. The harder you push the Yak, the better it gets and that's what I am expecting once I get my own Laser and start flying it hard.

The big Laser is the one EXP in the 60" lineup that I have not yet owned, so it's definitely time to pick one up and get started.

The Kit
Holy cow is this thing huge! The box is so massive I almost wondered if they had sent me an 74" Laser by mistake! Unpacking the plane it becomes evident pretty quickly that the big Laser is a large airplane for it's wingspan, even by EXP standards. The fuselage is simply immense. Also large are the fin and rudder. Everything is just big on this plane.

 

Hardware is almost identical to the other 60 size EXPs. If there is a difference, I can't find any. These are the same ball links and pushrods we are used to working with, which is great because they give a nice, tight and slop free connection from the servo to the control surface.

Again featured is Extreme Flight's most excellent tail wheel assembly. I love this unit because it is very simple, and if you have a problem you can change the whole thing at at the field in about thirty seconds with just three screws. It is easy to set up and easy to maintain.

The last few EXPs I have gotten featured an improved tailwheel steering arm. The new arm features a bigger center section with more area where the two pieces are pressed together. I've been running these arms on my 60" Yak, 60" Extra and 48" HV Laser and they are staying solid. If there was one thing I would have improved on the EXPs, this would have been it, and now it's done.

Worth noting is how large the air intake nostrils are on this plane. The laser has a very wide cowl, especially around the cheek area, and this allows for a huge cooling inlet area. The kit comes with air deflectors that mount on the motor box and direct more air to the motor, but I don't think they will be necessary, even in the Florida heat.

Above we are about six hours into the build. All that's left is installing the servos and hooking up the pushrods, and that's only maybe an hour's work. I like to pre-fit the servos and remove them so I don't risk getting glue into them when I put the tail on.

That, and at the time of the photos, I didn't yet have the servos. I used a spare HS5245MH to drill the screw holes (they are identical to the HS7245MH we will be using). All that is left now is screwing the servos in and hooking up the pushrods.

The only thing I worry about on the 60 size EXPs is getting the right holes cut in the fuselage for the servos, but my Yak and now Laser came pre-cut, and nicely too. This took a lot of stress out of the build because I have gotten this part wrong in the past and had to patch things up, not something I enjoy on a brand new airplane.

On this model, installing the stabilizer took a bit more time than usual, but the reason is, admittedly, a bit odd. I slid it on and simply eyeballed it to get it sort of straight enough to begin measuring. Unbelievably, it was absolutely dead on perfectly aligned all the way around. Anything that is this easy is usually a trap, so I started to get a little paranoid that something was wrong or that I was measuring wrong or something.  I must have measured it fifty times because I could not believe how straight it was. It was so easy that I was getting worried, so I set it aside and installed the pilot. Some times you just gotta walk away for a few minutes and do something else instead of getting stressed out about one thing. When I came back to the stab, it still measured out perfect, so I nailed it down with CA.

Mostly the whole thing went together almost before I knew it.

 

Servos Something different for this project are the HS7245MH servos that Hitec Multiplex was kind enough to send me. I've used these on my new Extra and am very pleased with them. High voltage (HV) servos 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. These were the recommended servos for the Laser from the beginning.

I had held off on trying these servos because they are a bit expensive compared to what I am used to using, but expensive servos are generally expensive because they are worth it. The additional torque and speed will come in handy, and the better centering will compliment the plane's precision nature. These servos made the Extra a better flying plane so there was never going to be any other choice for this plane.

7245MH webpage

Specifications

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

I haven't had the chance to put a lot of flights on the 7245MH in my Extra yet, but I was very impressed with them. With more torque and holding power they won'[t be working as hard, which hopefully means they will be even more reliable and care free than my trusty 5265MGs.

Having said all of that about the HS7245MH, my HS5245MGs were still dammed good servos. I still  have my original set in my MXS, and both my Yak and Edge also use the 5245MG.

BEC Set Up
Once again I'll be running a Castle 10amp BEC, just like I did on my 60" Extra. This time I am a lot happier with my installation because it is out of the way while still in the airflow.

SET UP

 

If this text looks like a copy/paste from the Extra article, that's because it is. The boss figured all the control set ups on the first 60" EXPs, and they are all virtually the same. All the EXPs use dual ball link hardware and G10 control arms, so if you have built one, that's as good as having built them all. It's nice to go into a new build having seen all of it before in the other EXPs. I pretty much knew exactly what to expect for the build and the set up.

 

I went for every bit of elevator travel I could steal. The laser is really huge and all of that area generates stability. To get the most agility out of the plane I can, I really needed to watch my control movement and get as much as I could. After the hinging was done I can move the elevator up to about 80 degrees from center, and that was with a pretty tight hinge gap. 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 Laser is going to spend a lot of time going very, very fast. 

 

 

Servo Arms 

 I used Hitec's PN55709 arms when I rebuilt my 64" MXS and later when building my new 60 Edge, Yak and my newest Extra. These have held up really well, and they just happened to be the exact same size as arms I was using previously. 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.

 

Linkages

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.

Aileron Set Up

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 other 60" planes, this time I was able to get 75 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.

I had to trim the arm just a little to clear the bottom of the stab. If I had this build to do over again I would cut maybe 1/8" off the bottom of the servo opening and drop the servo down just a little. I don't need to get any more throw .... just a little more clearance.

You may notice this set up is a little different from the manual in that the servo is turned around (opposite from what is in the manual) and the output shaft is closer to the tail. This way I was able to thread the ball links deeper on to the pushrods. They are very close to being totally bottomed out on both ends. In fact, they probably are past that because I used a drill to spin them in. Since they are translucent white, I could see how deep the pushrod was going in and stopped before I screwed the pushrod out the other side! I think I had to back one ball link off a couple of turns, but outside of that, they are screwed as deep onto the pushrod as they will go. It would take a nuclear explosion to pull one of those pushrods out.

If you try this, you may very well ruin a ball link, so make sure you have a few spares around.

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.

 

Flying

Unfortunately what was perfect building weather (cold, rainy) is not so good for testing a new plane, so we haven't had a chance to fly the plane yet. We'll save that for a new article once we have a few flights on the new Laser and get some video too. Hopefully that will happen quickly.

Spoileron Mix

I've been playing with a 50% spoileron mix on some of my 48" planes, Laser, but never really put enough effort into it to give it a fair chance until recently on my new 48" Laser. With spoilerons, the ailerons will work together in the opposite direction of the elevator, though they remain independent and still work as ailerons too. Spoilerons come in real handy for a few things, but we'll get into that later.

 

At first I didn't like the effect, but it turns out that 50% is too much mix unless you are going to be turning it on and off all the time depending on what you want to do. One of my buds over at RC Groups says he likes 37%, so I set mine up for 30 and tried it again. This time it was much better. I can leave the mix on full time and the plane even harriers and hovers better this way. I'de say the 48" laser with the mix harriers very close to as well as the 48" Edge does, which is saying something. At this point, it is so close to being right that I may try 25%

 

With the mix on the plane will do the most straight down elevator drops you have ever seen ...... totally sick. With 50% mix the plane fell too fast, but at 30% it's much better. Also, parachute maneuvers are more interesting because instead of popping to a stop the plane will rotate to flat, but keep sinking at a high rate of speed. Essentially you are using a parachute to enter a high speed elevator maneuver. With 50% mix the thing would fall so fast that I almost put it in the dirt a few times, but with 30% I can arrest the speed quite easily with power. In fact, I did a parachute into a high speed elevator and rode it all the way down into a perfect harrier landing.

 

I don't want to get too much into the flying aspect of the spoileron mix just yet because I think maybe this deserves it's own article. The mix is definitely very interesting to play with, and it also opens up the envelope of things you can do with the plane. This mix will be on the 60" Laser, though I suspect I won't mess with it much until I have a good feel for how the plane flies without it.