Building the Raptor 50 Titan RC Helicopter

For a year or so I’d had the use of a loaned Raptor 50 RC helicopter to play with and it was a lot of fun. Having a little 50 to muck around with is great, you don’t have to think with a 50 like you do a 90, you just play.

Raptor 50 Titan
Raptor 50 Titan

I gave that little Rappy a good pummeling trying all sorts of craziness which would often result in the Rappy on it’s side on the ground after a good bounce off the ground.

It was a good honest little Rappy and when I gave it back to it’s owner I thought that I’d have to get something to replace it, eventually. Until then I’d play with the Vigor and the Sylphides.

I didn’t do anything about replacing the Rappy for about six months until my mate Andrew got a Raptor (along with everyone else) and I was the odd one out. The Vigor is great to fly, but there’s nothing like a little 50 to throw about.

I needed to get a new Raptor.

Having got rid of the Synergy I had all the radio gear left over from that so all I needed was the kit and an OS 50 so I went and leaned on the local dealer and walked out with a new Raptor 50 Titan, OS 50 and SAB Carbon Blades.

The Titan 50 is Thunder Tiger’s newest version of the well proven Raptor 50. The differences between it and the ‘classic’ V2 Raptor are:

  • Longer tail boom to accommodate 620mm blades
  • Push-Pull system for collective pitch and elevator control
  • Rear mounted tail servo
  • Hardened main shaft.
  • You can also get an optional 8.7:1 gear ratio (up from the standard 8.5:1).

Apart from that, it’s just a standard old Raptor, which is exactly what I wanted. Why didn’t I go for the SE? Well I already have a metal head block for the Raptor 50 and in my opinion, that’s really the only upgrade that’s needed. The purpose of a 50 is for cheap fun that I’m not afraid of crashing because of the cost.

The setup for this helicopter would be:

  • Futaba 9252’s on cyclic
  • Futaba 9255 on collective (one of the servos I had on the Synergy)
  • OS 50 Hyper
  • Hatori 522 muffler
  • Futaba GV-1 Governor
  • Futaba GY601 Gyro
  • Duralite 5.3 regulated battery system.
  • SAB Carbon 600mm blades

So with all of that, it should be a fun little setup!

Opening the helicopter box up yields a whole heap of bags full of bits as well as the provided Thunder Tiger wooden blades (which won’t be used). Also supplied is a small little exhaust (which also won’t be used).

The big ‘milk jug’ canopy took up the majority of the space and everything else appeared just as Raptors do, very simply.

The first components to assemble is the fuel tank (which is assembled from the factory) and also the clutch bell pinion. The pinion is a ten tooth affair. Thankfully the clutch liner is glued in from the factory which is good.

Next is the main gear and autorotation hub assembly which is very easy to assemble apart from the circlips that go on the autorotation sleeve. I lubricated the one way bearing with Tri-Flow lubricant and went to work putting the circlips on. After ten minutes of getting no where I jumped in the car and went and purchased circlip pliers and we were done. Circlip pliers are a worthwhile purchase.

The plastic washout arms are straight forward, once again circlips are used to secure the pins. Perhaps one part that might be worth while upgrading in the future is the washout and washout arms. The plastic was just a little too flexible for my liking, but I won’t upgrade those till I bust these.

There’s not much you can get wrong with a Raptor RC helicopter. Things either work or they don’t, there’s no middle “that MIGHT work” way to assemble these things. Raptor frames are no different, you just lay a frame on it’s side, push the crossmembers into the pre-moulded holes, push the bearings into their pre-moulded housings, push the tail belt idlers in, install the clutch bell, servo tray and fuel tank then lay the other frame on top and you’re done. So very simple.

The elevator cradle then slides in between the frames under the top mainshaft bearing, you have to pull on the frames a bit to get it in but it’s not hard.

Once in, you slide the servo tray ends over the ends of the elevator cradle. I really like the way the Raptor servo tray works, it’s so very simple, yet very effective. Bearings are used to support the tray at it’s central rocking point where the push-pull elevator linkage is mounted.

The push-pull linkage is a great addition which eases the load on the elevator servo and as such, makes the ‘feel’ of the elevator servo more responsive.

The Raptor’s fan was the worst balanced fan that I’ve ever had the displeasure of encountering. When I first put it on the balancer I thought I’d made a mistake as it would suddenly roll to one side so quickly I thought there must have been something stuck to it.

There wasn’t – it was just terribly balanced.

I ended up removing A LOT of weight from the ‘heavy’ side of the fan, so much so that I was getting to the point of not knowing what to do next if I hadn’t removed enough, perhaps I should start adding weight to the ‘light’ side? Unfortunately there wasn’t a moulded location to glue the GV-1 magnet in on the ‘light’ side, so I had to pick the best of the bad situation.

In the end I go the fan to balance within reasonable tolerances, if this was my F3C machine I would probably have thrown the fan away and got a new one and tried again, but this is good enough for a 3D machine.

Normally, once balanced, I would dial gauge the fan on the crank shaft but because Raptor fan hubs are threaded, there’s really not many options, so I was at a loss there. It would have to do.

This little exercise just bought home the point these things need to be checked prior to assembly and if I had this much trouble getting things to be even close to right, how would a novice to the hobby get on?

If you’re having trouble with vibrations in your Raptor, it could be a good idea to check your fan balance, cause mine was shit.

With the clutch installed I installed the engine into the frames which was a very straight forward exercise which makes a pleasant change from the JR machines I have which REQUIRE scientific accuracy in the engine placement to ensure that everything is happy.

Following the engine installation is the skids, nothing unusual to report there.

I already had a metal head left over from the other Raptor and intended to use that on this helicopter.

Assembling the head was very straight forward, I greased the thrust bearings and installed the harder red dampeners.

One thing I really like about Raptors is that the flybars have small slots in them where the flybar arms screw into. This is great. No mucking about with measurement or anything, it just works.

I used loctite to secure all the bearings in each part of the head to ensure minimal slop which I achieved.

I also made sure to use a ball link reamer on each ball link on the head to ensure that while the links were a tight fit, that they were smooth and did not ‘stick’ which is crucial.

I did not get too specific with the rod lengths as I will cover this in the subsequent ‘setup’ article.

Raptor tail boxes just work, there’s not much that can go wrong with these things. There’s a large central hub that is fixed onto the output shaft by two large set screws which a lock-nut then threads onto. Once that’s done the large plastic tail grips are fitted over the bearings and it’s all done.

The tail pitch slider assembly is also very straight forward and very free of slop. The gear box itself is well supported by bearings at each end and has a large pulley for the belt in the middle with an idler pulley at the top. Once all bolted together it’s all nice and free with no slop. Very easy.

The helicopter boom is great. At one end there are two holes, at the other there are two slots, you can’t get them mixed up, the tail box goes on the end with the holes (there are mouldings that fit in the holes) and the other end slides into slots. You can’t get it wrong.

Feeding the tail belt down the boom can be a pain, but I generally attach one end of the belt to a long stick and push it through. The belt then slides around the tail drive gear below the main gear.

The one thing I did change from standard is the use of a JR Venture 50 boom clamp which means that I don’t have to run a horizontal fin (which I try not to do on my 3D machines).

Once the boom is fitted with the boom supports the whole tail structure is very solid which is great to see.

The tail push rod slides easily through the three pushrod guides which with the tail mounted servo should provide a smooth flowing tail linkage.

The first servo to be fitted was the collective servo. The Raptor Titan uses a push-pull collective linkage which works really well, this once again reduces the load on the servo and improves pitch response which I’m all for.

This is all done putting the intermediate bell crank linkage in the servo bay where the tail servo would normally be on ‘classic’ Raptors. Thunder Tiger provide an impressive plastic mount that is very reinforced which I very much doubt will flex under loads.

I’m always keen on installing the ball link on the servo tray in the hole closest to the main shaft which meant that the collective bell crank would be installed in the hole nearest the front of the helicopter. This would yield the best pitch response.

The pitch servo is mounted using two standoff blocks to push the servo out from the frames and make the linkages straight up and down.

I’ll cover the setup of the collective linkage in the subsequent setup article.

Fitting the aileron servo is very straight forward, except that you should tape the servo lead to the bottom of the servo to stop it fouling on anything untoward in the frames.

The elevator servo is also mounted on standoff blocks to push it out from the frames.

I’ll cover the setup of the aileron and elevator linkage in the subsequent setup article.

The Titan has a boom mount for the tail servo. Something I’m generally not in favour of because it leaves the servo more exposed to damage in the event of a crash, and also the servo tends to fill with exhaust oil over time. I’m more in favour of mounting the servo up front, however in the configuration I’m using, that’s not an option.

I’ve mounted the tail servo so that the tail pushrod is under the middle of the boom at all times to try and prevent the pushrod deviating from the line that it naturally wants to take which makes for a freer flowing action.

I wanted to keep the GV-1 sensor out of the way so I generally end up mounting them on the exhaust side of the engine. I test fitted the sensor a couple of times to get the positioning just right so that the GV-1 was reading 97% reading, I then put some headshrink around it to try and make it more robust. Once done I mounted it back into the helicopter and tested the reading to ensure we were still getting 97%.

The little Raptor rc helicopter doesn’t have much space to locate all your electronics, infact, it doesn’t have much space AT ALL. Unfortunately I had a lot of stuff to locate! A gyro head unit, governor head unit, battery, receiver, and battery regulator!

I’m not great with wiring these things tidily however I ended up routing all the servo leads in one common path which at least gave me some control over where everything was going. I used one Velcro receiver wrap to contain the governor and gyro headunits as well as the receiver then fastened it all to the radio tray with double sided tape and electrical insulation tape. I tend to use insulation tape because you can get a good grip on everything and it tends not to let go like some Velcro can if not administered properly. It doesn’t look great, but it works great!

I’m not great at the best of times with cutting out milk bottle canopies, I can never seem to get the smooth edges that others can! My Raptor canopy fared no better really, while it’s easy to cut the canopy out, it’s hard to get it really nice, but I think that’s more to do with my lack of skill than anything that Thunder Tiger have done.

I made a bit of a mess of the stickers too, once again due to my lack of skill, but I was able to save a little dignity in the end by cutting the bubbles that appeared in the stickers later…

I cover the setup of this machine a separate article.

Excited to get back to having ‘fun with Raptors’ I took the little Rappy to the field and cranked it into life. The little Hyper instantly purred into life which surprised me and lifted straight off into a hover with no problems at all. As expected, no tracking was needed, and only a couple of clicks of trim. The little Rappy purred away as happy as a cat lapping at a bowl of cream.

Happy with how things were going, I turned on the governor and the engine slowed down a little. At first I was suspicious that the governor wasn’t holding the headspeed at the correct speed (1650) because it sounded quieter than I expected, however a quick check with a tachometer confirmed that indeed everything was correct.

I hovered the little Rappy around for a tank then landed to make sure nothing had come loose. Nothing had.

The next flight it was time for some gentle aerobatics. I’m not one for spending tank after tank just hovering round ‘running in’ an engine, I believe in ‘start as you mean to go on’ by which I mean fly it normally, but don’t load the engine up and gradually lean the engine out until it’s operatoring optimally.

Into Idle Up One and the engine started singing at 2000RPM and I began doing some circuits. The rc heli flew nice and straight with the white paddles. I then did some rolls and noticed a slower roll rate than I wanted and also the machine wasn’t rolling straight which I was expecting. I leaned the engine out a few clicks as well.

I went back to the pits and got an extra 20% ATV out of the elevator and aileron controls to see about getting the roll rate up.

Second flight the roll rate was better, but still not what I was after, so the lighter paddles (red or green) would be required. I then started adjusting the phasing ring to get the roll straighter (I’ll cover this in a future article), after the second adjustment the little Rappy was rolling better than the Vigor!

The dampeners didn’t seem that good though. The red dampeners I had in it I had used in the old Raptor and were now seeming to be more flogged out than I expected as the machine was shaking during tic-tocs. I’ve ordered some CarbonExtreme Dampeners to try so that should be interesting.

I also noticed that the tail would sometimes washout during some maneuvers, so I replaced the stock tail blades with some Carbontech 95mm blades which immediately fixed the problem.

Ah, it was great to fly a little Raptor rc helicopter again, at our field we have a flight station that is pretty congested with a fence, some trees right in front of you, some more to the right of you and you stand on a mound. With a 90 you have to think a lot to keep it out of trouble (ie the trees or the fence), with a little 50 you don’t care, you just chuck it around and it’s A LOT OF FUN!

Later in the day it was time for some push over autos and the SAB blades are just great at this, they spool up so well after the push over, you can skim the head button through the grass, do a big quarter loop then fly in backwards, lots of fun!

That night I put some green paddles and brand new red dampeners in. The roll rate was much better and the heli was still not pitchy (my main priority – I CAN’T STAND pitchy helicopters!) so we’ll stick with those paddles.

One thing I did do was shorten the long pitch links between the swashplate and the pitch arms by one turn to move some pitch off positive and onto negative to give a more even feel.

I can’t tell you how impressed I am with the OS 50 Hyper and Hatori 522 Combo, it’s perfect! I just can’t get enough pitch out of the little Raptor to even come close to loading it by doing climbouts. You can ofcourse load it if you make a screw up with cyclic and collective, but other than that, it’s a little power house, and ever so smooth!

I’m REALLY glad I bought the little Rappy, I’d forgotten how much fun they are to fly. I’m purposely not going to upgrade the heli any further than the CarbonExtreme dampeners, because it just doesn’t need it and I want to keep the heli as close to stock as possible so I can get parts easily.

What about all those flash metal heads Si? Don’t you want one of those?
Nah mate, nah I don’t. Firstly, because it’s just a waste of money, and I don’t want metal blade grips because they’re expensive to fix, and if they don’t break, then something else will. Also, I like the ‘give’ that plastic blade grips offer.

But what about the 4 million different types of setups you can offer with delta, flybar ratio, etc? Surely Si, with your F3C background, you’d want to play with all that?
Oh heeeelllll nah, that’s the last thing you want to do. Raptors fly great out of the box, they don’t need changing, just fly them. If you go mucking around with all sorts of flybar ratios and delta (and you don’t know what you’re doing) I can guarantee, your heli will fly like shit. Don’t over complicate stuff!

But I need to buy some upgrades to make me feel good about my Raptor rc helicopter, what should I buy?
Well now, you should make sure you have, in the following order:

  • Good blades (SAB, Carbontech, Radix, V-Blades etc)
  • Good engine (OS 50 Hyper)
  • Good exhaust (Hatori 522)
  • Good gyro (at least a Futaba GY401)
  • Metal head block (the Thunder Tiger one)
  • Good DIGITAL servos
  • Harder dampening (CarbonExtreme dampeners)
  • Faster paddles (Green or red ones)

Once you have bought all of the above, buy the following:

  • More blades
  • More booms
  • More spindle shafts etc etc

You don’t need all those flash metal bits! Spend the money on productive stuff!

So the little Rappy is now inducted into the fleet and joins the old trusty Vigor, the two Sylphides and the damn T-Rex (which is somewhere – still busted). You’ll see more of the little Rappy in upcoming articles where I test out some new hardware on it.

All that remains is to thank for the loan of the rc helicopter for my review.


A couple of weeks ago I came to the conclusion the ancient OS 91 C-Spec in the Vigor was sound like a rattly old diesel engine. I knew the old dog would need a bit of work done on it given that it has done so many flights in the last five or so years, so I tore it down to check it out.


I wasn’t overly surprised to see the ring didn’t have any spring left in it, the piston and liner had a few scores in it and the bearings weren’t overly good. I should say that during this time I’ve replaced the bearings every six months or so, but the rest of the engine is essentially the same as it came out of the box.

Given that OS parts prices are so hefty, I decided just to go buy a new engine. Given the old C-Spec had the Cline regulator system (which I can’t speak more highly about by the way, it’s great), I had thought about just buying an engine without a carb and using the Cline, but I decided to just get a whole new engine.

While the old C-Spec had treated me impeccably, I’d been very wary of OS engines since that disaster of an engine, the OS 91 PS (Perry Pump version) came out. I had one of those in one of the Sylphides and what a big piece of crap it was. You could get it to hover smooth, or make OK power (not great, but OK) for aerobatics but you couldn’t have both. After an assortment of carb spray bars from overseas I gave up and put a YS in both the Sylphides and haven’t looked back since.

So when it came time to replace the old C-Spec I considered going the YS route again, but decided to give the SZ range of engines a go, specifically the pumped version, using the proven OS pump that has been in use on planks for years and years.

The SZ PS does not use crank case or muffler pressure which means no more disintegrating clunk lines and is also regulated which means no change in engine tuning throughout the flight.

The PS comes with two extra head shims as standard, one thick, one thin (I can’t remember the sizes off the top of my head), I’d run an extra shim in the old engine which made it run quite a bit smoother, so decided right from the start to install the thick shim in addition to the standard one.

I installed an Enya 3 plug into the engine and bolted the engine into the Vigor without a problem and bolted up the Hatori pipe, however I had to sit and think about plumbing the fuel line up. Because the tank isn’t pressurised by either crank case or muffler pressure, the tank needs to vent to the open air so that fuel can be sucked from it.

On a heli that goes upside down a lot, there is obviously potential for the fuel to simply run out the vent line, all over the heli. The OS manual says you can “use a suitable one way check valve” to prevent the fuel running out the line and only letting air in, however they don’t mention a suitable one, and I’m not sure the normal valves such as the Perry or the YS one are really suitable for the task.

However a quick search on Runryder found that many guys had good success by running fuel tubing from the vent nipple to a spot below the tank. Apparently this, and the little amount of negative pressure generated by the pump sucking fuel is enough to stop the majority of fuel from running out of the tank while the heli is flying around. So I did that and it seems to be working so far.

True to form, OS’s recommended needle settings are way out so I didn’t bother with those. I set the top end needle to 1.5 turns out and hte mid range to 1 turn out and the bottom end just above half way knowing that would still be very rich. A quick flick of the starter saw the engine burst into life and sit there idling very well without any hint of coughing and dying which was great!

The heli spooled up cleanly with a TONNE of smoke and was very rich.

I’m not one for running my engines in mega rich. I like to get them up to normal operating temperature quickly, and then flying them round like normal making sure to not load them and most importantly, never overspeeding. I always make sure the engines are running ‘cleanly’ (ie they’re not coughing, four stroking or running lean). As the engines run in, you can lean them off a click or so at a time to really get the optimal performance out of them.

By the end of the first flight the PS was running nice producing good power, lots of smoke, running cleanly and cutting back instantly at the beginning of autorotations. I was very impressed so far with the engine. It didn’t seem to produce a whole lot more power than the C-Spec it replaced, but it was running as consistently and smoothly which was great.

Another 15 flights later and the engine is fully leaned out and performing great. The engine continues to run very consistently and is making very good power. Is it more powerful than the old C-Spec? Well I’d be hard pressed to say it was, it’s at least as powerful, but wouldn’t be massively more than the old one.

My final needle settings are 3/4 turn on top end, 0.5 turn on mid and 3/4 open on the bottom. Please don’t transfer these needle settings to your engine because your engine, exhaust, fuel, and style of flying (amongst other factors!) will most likely be different and you could do your engine harm if you don’t know what to listen for.

Would I buy another one of these engines? Absolutely, I’m very impressed with it so far, it’s certainly leagues better than the original OS 91 PS.

Futaba 12FG

Futaba has just released another new transmitter on the market taking advantage of their .  The Futaba 12FG joins the 12Z and the 14MZ in supporting the 2048 resolution which has set these systems apart from their competition and their predecessors.

Futaba 12FG
Futaba 12FG

At first I was a little confused as to where the 12FG fits in Futaba’s product line when there is already another 12 channel system, the 12Z.  When the 12Z came out I was a bit disappointed at how expensive it was.  I had been hoping for a much cheaper system to give a viable alternative to the 14MZ.  It seems that the 12FG has been designed to bridge that gap.  Taking US prices sourced from Tower Hobbies, the pricing breakdown between all three systems is:

System Price          
Futaba 9CHP (no servos) £399.99
Futaba 12FG (no servos) £999.00
Futaba 12Z   (no servos) £1374.99
Futaba 14MZ (no servos) £2199.99


You can see where Futaba have tried to save money on the production of the 12FG, however I don’t say that in a critical manner, all the cost savings seem to have genuine and reasonable rationale behind them.  The casing is now a cheaper looking plastic than say the 14MZ, however still has a quality feel about it.
The screen is a basic black and white LCD that most will be familiar with rather than the full colour version on the 14MZ.  Having said that, the LCD still contains a lot of information, much more than say the Futaba 9CHP.

Screen navigation takes place with a jog dial that you push to enter in the same way as the 9CHP.

The antenna is stored in the transmitter body in the same way as the 14MZ which is nice, however the antenna doesn’t ‘clip’ into the antenna base like the 14, instead you screw it in.  I think I prefer the 14’s method of mounting better.

The battery has reverted back to the old style battery (ie pre 12Z and 14MZ style) like the 9C.  My personal preference is for the camera style batteries of the 12 and 14.

The switches are the same as the 14MZ and have a good positive feel to them which is good.  There is a slider on each side of the body (rather than the two sliders on each side of the 14) and two dials available on the front face.

It’s good to see Futaba haven’t sacrificed stick feel either.  The sticks feel just as good as my 14MZ.

Different from the 14 is that the sides of the body don’t hinge open to reveal the Compact Flash card.  Instead, the 12FG uses an SD card that is housed in the battery area.

The 12FG uses the same module design as the 14 and the 12.

The 12FG feels solid in your hands, not cheap and nasty which is great, it feels a little narrower than my 14.  I fly finger and thumb and was very comfortable holding it like this.  It feels a little lighter than the 14 also.

Booting the 12FG up you’re asked if you’re really sure you wish to transmit, just like the 14.  Using the jog dial you can select yes or no to proceed to the main menu.

The menu is laid out in much the same way as the 14.  From the top left you have the timer functionality, throttle and pitch position, trim positions, current frequency, current model, currently selected condition, voltage, on air status, and then the menu selectors for System, Linkage and Model.

You can scroll around to select what you want to do very quickly using the jog dial.

The menus are structured in the same way as the 14MZ, infact very quickly I was very much at home with programming the 12FG.

The system menu contains all the settings that are applicable to the system as a whole (rather than individual models or conditions).  These settings are:

In the trainer menu you can activate all of the buddy boxing features.  Here can define whether the system will act as the teacher or student, whether it will run in 8 (for all Futaba transmitters except 14MZ, 12Z) or 12 (14MZ and 12Z) channel mode.

You can also set the modulation type (if in student mode) or the trainer switch used to activate the teacher transmitter (in teacher mode).

Once set, you can then go through each control (ie elevator, aileron etc) and define whether that control should be controlled by input from the student controller (NORM), or controlled by both student and teacher transmitters (MIX), another mode where you can define that the model is controlled by signals from the student transmitter using the teacher’s AFR settings or finally where the teacher retains complete command of that control (OFF).

Once selected, you can also define a rate for that control.  This means that you can ‘dumb down’ the sensitivity of the control for your student.  Very useful.

Here you can define the contrast of the LCD screen to make it more readable.  I found it best if this was set to 0.

Here you can display (and reset) the total operational time the transmitter has been running, and also, the total time each model has been operating (ie the model was selected and the transmitter was turned on).

Here you can enter (if you want to), your name so it’s highlighted on the main screen.  This can be handy if you and your mates all have similar transmitters and you’re trying to work out who’s is who’s.

H/W SETTING (Hardware reversing and stick mode)
Here you can (if you’d ever need to) reverse the operation of any of the sticks, switchers, trims and knobs.

From here you also set the stick mode of the system between mode 1, 2, 3 or 4.  Naturally, this doesn’t change the mechanical configuration of the sticks, you either get this done at a Futaba service center, or if you’re brave (and competent), do it yourself.

Here’s where you find out what version of software your transmitter is running.  One thing that I’ve been impressed with Futaba about is their fairly regular updates for the 14MZ.  These are free downloads that you install on your transmitter and include bug fixes, but even more than they they include extra functionality or improvement in existing operations.  It really is worth keeping track of these updates.

The Linkage Menu contains all of the ‘model wide’ settings that apply for the selected model as a whole.

This function allows you to see what control inputs are being sent to the model.  This is really handy when you’re trying to debug ‘strange’ movements from mixers that you may have forgotten that you’d enabled!

Just like the 14MZ, this is where you pick which model you want to select and also where you create new model programs.

This is where you define if the model is a helicopter, glider or fixed wing.  You then define the sub-type of model (ie swash type for helicopters).

You determine which frequency to run your model on here, be it PPM, PCM, or G3 MODE A/G3 MODE B.  The list of frequencies available to select from is determined by the country the system is registered to.  In this case, it’s Australia, so all of the available 36mhz frequencies are displayed.

In the function menu you dictate which control is going to work each surface (ie which joystick is going to work elevator, aileron etc).  You can also reassign trims (ie use cross trims if that’s what you want), you can assign sliders and dials to channels also which really increases the flexibility in configuring your model.

This is pretty straight forward, simply select the servo you wish to adjust and use the jog dial to alter the sub-trim value.

Not much to add with this one!

Critical to the setup of any model in my opinion is the appropriate setup of Failsafe on your model.  In this menu you go through each control and define what you want that control to do in the event of a failsafe.  I generally set all my controls to go to ‘neutral’ (ie no input), apart from throttle which I set to go to idle and also any goverors I set to turn off.
In this menu you can also define what you want to happen if the battery voltage drops too low.  You must also define which switch you wish to do to get the model out of battery failsafe in order to land it!

Also known as ATV, this is exactly the same as the 14MZ.  You setup both the travel and the limit.  The travel defines how far the servo will move for the given control (ie aileron) and the limit defines how far the servo will travel with mixes involved.

You can also slow the servo down using the ‘speed’ property if need be.

This works in exactly the same way as the 14MZ throttle cut feature.  You define the throttle position where the function can become active is commanded by the defined switch.  This prevents accidental activation of the cut switch when say at full throttle.

You then define the position to move the throttle body to on activation to cut the engine as well as the switch you’ll use to activate the function.

This is one of the features that turned up in the 14MZ in one of the latest updates and is a great feature.  Basically what it does is reproduce the mechanical action of a ‘swash ring’ (can be installed on Mode Two transmitters).  This allows the transmitter to prevent binding when the stick is in extreme corners.  It’s a really good feature.

This is where you define your CCPM settings for the model (ie aileron, elevator and pitch rate) as well as the full CPPM compenstation features available in the 14MZ!  I was surprised to see this functionality included actually, I thought they might have disabled this in order to have a good feature differential between this and the 12 and 14.

Here you can setup how you want the timers to work for this model.  On my models, I have the timers set for 10 mins and are controlled via stick position.  For example when the throttle stick moves above idle (ie flying) the timer begins counting down.  When the stick is at idle, the timer is paused.  In this way I have a pretty accurate account of how the fuel is going in any of my machines.  You can set timers to be any time you want and also have them count up or count down.

You can manage the settings of your trims in this screen.  You can split the trims between each condition (different trim settings for each condition) or you can have one trim setting across the model.  You also define which trim control is associated with which trim as well as the step increments that the trim will move for each movement of the trim control.

From this menu you can reset the values of the trims, the condition and the model.

The Model menu contains the configuration for each condition/flight mode (ie normal mode, Idle Ups and Hold).

This area accesses the Servo Monitor functions described above.

This is where you create, edit and delete the conditions to be used with this model.  Commonly for a helicopter, that would include Normal, Idle Up 1, Idle Up 2 and Hold.  You also define which switches activate these conditions and the priority of those conditions.

I use AFR for exponential and dual rate controls.  While there is a seperate Dual Rate menu, I tend not to use it and only use AFR in order to keep things simple.  This function works just like the 14MZ.  You select the type of curve you want (although you can only select from Exp1, Exp2 and Point – still more than adequate I only ever use Exp1).  You then define if you want these values to be grouped across conditions, or for each singular condition.

I’m unsure why Dual Rate is still included as I use AFR to achieve the same result.  However if you do want to use Dual Rate, you can have up to six rates assigned for each condition, which is a large amount.

This is where you can define mixes that you might need for your model.  However before you go configuring mixes here, check to see if the mix you want has already been defined in the ‘Swash Mix’ function.  If it’s not there already, create your own mix here.  As with all mix settings in this model, you can have a mix grouped with all conditions, or to each individual condition.

The 12FG once again has the same pitch and throttle curve programming as the 14MZ, the same amount of moveable points on the curve (17 points), the same options available in terms of type of curve, offsets and trims.  You can set the curve to represent the actual degrees of pitch on the blade also which is pretty cool.

As with the Pitch Curve programming, the throttle curve functionality is the same as the 14MZ, the same amount of moveable points on the curve (17 points), the same options available in terms of type of curve, offsets and trims.

This is a feature I’ve just started playing with on my 14MZ, it’s great for 3D.  Basically it allows you to set the radio up so that during sudden pitch (and throttle if necessary) movements, it will overdrive the pitch function by an amount defined by you, then gradually return to the actual pitch setting represented on your curve over a duration also defined by you.  This means for instance, if you set your curve up with 10 degrees each way, you can use Accelleration to give your pitch curve a burst of 11 or 12 degrees pitch to ‘pop’ the heli, then it will automatically ramp it back down to 10 degrees to avoid loading the heli too much.  It’s a great function!

Here you define the throttle hold behaviour of your engine.  There are two modes available, one to reduce the engine to idle, the other to actually cut the engine.  You can set different switches to each mode.  For F3C, I use a slider to define the idle position of the engine so that I don’t have to remember before a competition to set the throttle hold to cut.  I use the slider so that when it’s all the way up and throttle hold is activated, the engine goes to idle.  When the slider is down and throttle hold is activated the engine will cut.

The great thing about these radios is that you can set them up to run how you like!

Just like the 14MZ, the 12FG has all of the popular mixes you’ll need (ie AIL to ELE, ELE to AIL, PIT to AIL etc) already pre-defined, so all you have to do is adjust the values.  Each mix has comprehensive settings to really fine tune the mix.  I use AIL to ELE a lot to make sure the helicopters roll straight.  In most cases, the Swash Mix menu will contain all the mixes you’ll need for your machine.

Like Swash Mix, this menu has pre-defined mixes so that you can add cyclic to throttle and rudder to throttle mixing without using any Program Mixers.  Even though I run governors in my machines, I generally run throttle mixing so that if the governor fails, it’s not going to be a big deal.

Infact for a long time, I didn’t run a governor on the old Raptor and just set it up with throttle mixing and it worked great.  The only downside is when you’re going full pitch at the ground the engine will overspeed.

If you feel like running inflight needle mixing, this is where you define the curve the needle servo will follow against the pitch curve.  This is useful if you find you want to say lean the engine out when at full pitch or richen it up in hover.

With this function you can change pitch input depending on rudder input.  This was used in the old days when Non-Heading hold gyros were popular.  It’s used to try and suppress the increase in torque force on the tail when applying pitch, and the decrease in torque when pitch is removed.  If you’re running Heading Hold gyros, this function doesn’t get used.

Here’s where you define the gyro settings.  If you have a Futaba GY series gyro, this is really easily.  You just select ‘GY’ from the menu and enter the gain value that you wish to see on the GY’s head unit, it’s very well integrated.

This feature is great on the new Futaba radios.  You can set up your GV-1 governor so that you just type in the actual headspeed you want (ie no percentage figures) and the GV-1 will pick it up.  You can ofcourse use non-Futaba governors by using the percentage features as well.

One thing that I do use this for is on my F3C Sylphides.  I have one of the sliders set up to manipulate the governor headspeed in normal mode only.  For example, if it’s a very calm day, I move the slider down to reduce the headspeed, or conversely if it’s very windy, I move the slider up to get more headspeed.  Because this setting is only active in normal mode, the slider setting does not impact on any of the Idle Up settings.

Like all of the programs available in this transmitter, you can seperate each governor setting for each condition, or you can group your settings across multiple conditions.

Condition Hold allows you to lock the throttle servo at Idle position to allow you to switch between conditions (for adjusting pitch and throttle curves or any other condition specific setting) without the heli following that condition’s throttle settings (ie going from Idle to 100% throttle when switching from Normal mode to Idle Up One).

I like the 12FG.  Infact, I can’t understand why Futaba have made it so good, as there’s really no point in buying a 14MZ, and there’s DEFINATELY no point in buying a 12Z after looking at one of these.

I was immediately familiar with all the controls and settings of the 12FG since I am very familiar with the 14MZ which is lucky, because in true Futaba tradition, the user manual is less than average at explaining things.

I was expecting to find quite a number of the ‘key’ 14MZ features left out of this as a product differentiator, for example I didn’t expect to see the CCPM Compensation features, the Swash Ring, maybe even Acceleration, infact I wouldn’t have been surprised if the G3 modulation wasn’t there. Instead I sit here thinking, what did they leave out that’s in the 14MZ? Off the top of my head I can’t think of anything significant. Sure the pretty LCD touch screen, the nicer casing, the extra two channels are all nice, but they don’t justify the extra price.

So what were Futaba thinking? I for one can’t see why you’d buy a 12Z or a 14MZ over the 12FG. The 12FG has all the good features of the 12 and 14 at a much cheaper price. In the US, Futaba are advertising a 12FG 2.4ghz system although it doesn’t say when it will actually get to market. Given that no one at the recent F3C World Championships had Futaba 2.4 sets yet indicates that the systems are probably still a little way off yet.

So, if I were looking to buy a new transmitter right at the moment would I buy a 12FG? Yeah I would, most definately. Would I buy one over a 14MZ now that I’ve had the 14 for a couple of years? Yes, at less than half the price of the 14MZ (as judged from prices on the Tower Hobbies website), then it’s very difficult to justify the extra money for the 14. The 12FG represents awesome value for money.

JR Vibe 50 First Impressions

When I heard that JR were releasing a new 50 I was a bit sceptical. JR have always seemed to miss the point when it comes to 50’s. The Voyager wasn’t a bad machine, but needed upgrading (paddles, dampening, spindle shaft, slipper clutch) in order to do decent 3D. It suffered from a bad cooling design and you could bend spindle shafts at will with those.

JR Vibe 50
JR Vibe 50

The next 50 they released was the Venture 50 and the less said about that disaster the better. It was a fat and heavy plastic design that was repurposed as a Robbe Ornith and later on modified and sold as the Tiger by Audacity Models. Once again, before you started to do any harder kind of 3D with the Venture, you had to do something about the soft dampening the slow paddles and the general all round slop.

After the Venture, JR released the Airskipper which was better than it’s predecessors, but too expensive and never really took off.

Well now they seem to have it right in their latest release, the Vibe 50. Using the Vibe name is a bit of a gamble, they’d need to make sure the machine they associated the name with was as good as it’s bigger brother, the popular Vibe 90. Finally JR have given decent dampening straight out of the box, as well as a driven tail, good paddles and FINALLY a decent cooling system! It’s always bewildered me why JR have used very average cooling systems on their little helis (even the Sylpide 90), when they already have a great cooling system on the Vigor/Vibe.

Infact, there seems to be a lot of different influences in the little Vibe and not all from it’s bigger brother either. Infact the head setup looks remarkably similar to the Synergy design with the mixers on the leading edge of the very beefy blade grips. The central head block is a big square structure just like the Synergy.

You can adjust your flybar ratio just like the Vibe 90, and it comes standard with a flybar cage.

The main gear is attached to a nice big beefy auto hub with a split gear for the tail which is great, and the main shaft is supported by three bearing blocks. The clutch has two pre drilled holes in it for governor magnets, just like the Synergy.

My favourite part of the little Vibe is the fully enclosed mini-Vigor cooling system, the air is sucked in from the top and blasted down the enclosed ducting and over the engine head. The big Vibe has one of the best cooling systems going, so it stands to reason that the little Vibe should benefit too.

The CCPM system is based on the Vibe with push-pull linkages driving the swashplate that can be configured in both 120 or 140 CCPM.

The belt driven tail looks nice and strong, although the tail bell crank is plastic similar in design to the Caliber 5’s bell crank which on the Caliber 5, is useless. Time will tell if the little Vibe’s crank is as useless, but I would have liked to have seen that part as aluminium.

The Vibe belongs to James Dargue, a sponsored pilot for the Australian JR distributor, Model Engines. James is an extremely good pilot, but unfortunately is Mode One so I can’t fly his machines (I’m one of the very few Mode Two pilots at out club), but James gave the little Vibe a flogging.

Straight out of the box the heli flew very straight and true. There were some issues with the tail wagging, but that seems to be related to the gyro and tail servo combination being used at the moment. The roll rate seemed very good and the tail performance while not as good as a 90 (I haven’t come across a 50 whose tail was as good as a 90) looked to be as good as my little Raptor.

The Hyper and Hatori 522 combination was pulling very strong with a headspeed of just over 2050 RPM, we felt reducing the headspeed would probably be in order.

Finally it looks like JR are onto a winner with the little Vibe. No upgrades needed to do hard 3D out of the box and with the proven heritage of it’s bigger brother the Vibe 90 (and a few others like the Synergy), I really think it’ll be a winner.

How the market place responds to it will be another thing. JR are notorious for having expensive parts, so it will be interesting how both the kit and spare parts are priced. If they’re reasonable, then it’ll be a great machine.

Would I sell the little Raptor to buy one? No, I wouldn’t. But if I pummeled the Rappy into the ground I might consider replacing it with the Vibe.

Pricing hasn’t been annouced yet for Australia, but Horizon Hobby in the US have priced it at US$600 a kit. Availability also hasn’t yet been announced.

Check out the pictures and come to your own conclusion, but I think JR are onto a winner.

JR 770T Gyro

For many years now I’ve never thought much of JR gyros. Their transmitters and servos are all first rate, but for some reason, their gyros never really held a candle to the Futaba GY range of gyros. Futaba gyros just seem to work, take next to no setup and perform extremely well. While I have seem some JR gyros go well, it’s often because the user spent a hell of a lot of time setting them up, invoking all sorts of black magic and just happened to get one that worked, because there were plenty that didn’t.

Could it be now that things have changed? In 2007 JR released the new JR 770T gyro which when you look at it, reminds me of a GY401, it’s just a little box with no head unit, a couple of dip switches and a dial to set end points. This in itself is good because modern helicopters seem to have less and less space for all of the electronic wizardry we’re inclined to use these days!

JR 770T Gyro
JR 770T Gyro

The 770 also comes with a new high speed 8900 servo with a heat sink case built into it like the Futaba GY6XX series servos. The 8900 has impressive statistics, 0.5 second transit time and 1.36kg of torque.

I went through the instructions for setting the 770 up on my 14MZ in a MA Stratus. Set the ATV’s at 150 it said. Hmmm, if you do that with a GY series gyro, the piro rate is going to be blinding! Moving on, I then set the servo limits using the same method as the GY401.

One thing that wasn’t clear in the instructions was what to do if the servo wheel is slightly off center, are you able to use sub-trim? Luckily I did not need to, but still, would be interesting to know.

I then checked to see if the rudder needed to be reversed, which it did. I then swung the tail to see if the gyro needed to be reversed and found the gyro wasn’t responding at all! Hmmm. Another look at the instructions yielded no help, but I suspected that the gyro gain lead may have been plugged in wrong. It’s not clear which way the plug goes into the reciever as it only has one wire attached to it and it’s not clear which way up that goes into the reciever. Sure enough, reversing the gyro gain plug saw the gyro come back to life. The gyro didn’t need to be reversed for the Stratus.

Now onto the gain setting which had me going for a while due to my own fault. I hadn’t taken the model program’s gyro setting off AVCS and so moving the gain under 50% which should have yielded normal mode operation (above 50% is heading hold) was yielding nothing! Once I switched it off AVCS, everything came right.

The instructions talk about using Dual Rate and Expo to adjust the feel of the gyro during flight. I’m not sure why you wouldn’t just adjust ATV to change the piro rate? Surprisingly, JR recommend setting the expo of the rudder to 50% (for Futaba that’s -50%)! I very much look forward to finding out how that’s going to feel!

After a few flights I decided to reduce the ATV’s back to 100% and adjust the Expo setting to my taste just like you do with a Futaba. I really don’t understand why JR advocate setting the limits to 150%.

The helicopter lifted off with no troubles and in hover seemed ok. The initial tail response around center was good, but I didn’t give it any full rudder commands just yet.

In forward flight the tail started wagging, so I landed and wound the gain down, much better this time, however in forward flight the response around center felt a bit strange, like there was not much going on, then all of a sudden a whole lot, just like you expect with a lot of expo…

Once back in the air I decided to test the full piroette rate out and not surprisingly, the helicopter turned into a blur with a piroette rate so fast it was unusable. I landed and reduced the ATV from 150 to 100% to try and get a more controllable piro rate.

I began some piroetting flips to test the response when the tail on the Stratus failed due to the boom slipping back and losing tail drive. I hit hold just before it went in, unforutnately when I flicked out of hold after it hit, I was still in Idle Up so a fair bit of damage was caused.

I haven’t flown the Stratus since it went in, but I have had a number of experiences with other JR 770’s since then. One on a T-Rex 500, where the 770’s very small footprint is ideal and another on a Synergy N9. I met the Synergy when it’s owner wanted a hand to get the engine running right and get it to fly nice. However the machine’s tail performance was terrible. The tail was wagging a lot and letting go very easily. Changing gains didn’t seem to yield much change at all, it was really annoying the owner who was ready to throw the 770 out for a Futaba GY611.

Given that I have seen and experienced 770’s that go well, I figured we should be able to get it to work. One thing that did stand out on this machine was that the gyro was tightly strapped down on it’s mount. I see this a lot, and I’m not a fan. I think strapping the gyro is OK if you do it LIGHTLY. If you strap it down tight, you’ll just be transferring vibrations from the airframe directly into the gyro sensor.

The first thing we did was remove the gyro strap which yielded an immediate improvement. The next item we tried was swapping the thin and hard gyro tape for some of the thicker green Zeal tape. Once this was installed suddenly the tail came good. No more wagging.

Then I spent some time on the engine and got that running smooth so that the gyro wouldn’t be affected. After that we just gradually wound up the gain until the tail was holding as required. Once that was done, the tail performance was very good indeed.

The tail never stepped out during rolling tail slides or fast backward aerobatics and I didn’t detect any changes in piroette rate during piroetting maneuvers such as piro flips.

I must admit to being vary wary of trying this gyro. I’ve never really seen a JR gyro go well, and deep down, didn’t expect this one to be any different. However I was pleasantly surprised at how it just worked and showed a lot of potential right from the start. The 770 seems to be a lot more sensitive to problems than say a GY series gyro which are very forgiving of less than ideal setups, but once all the components such as mounting, engine vibration etc are satisfied to it’s requirements, then it performs very well indeed.

Are you missing any functionality from a 770 that you get in a gyro with a head unit such as the GY611? I don’t think so, especially for 90% of pilots who wouldn’t touch the advanced settings in the GY611 menus anyway.

I would definately be happy to buy one of these for a small heli like the T-Rex 500 where the small footprint is just awesome, and I’d certainly buy one of these over a GY401, however I’m not yet convinced the gyro is better than a GY611 on a 90 size, simply because I haven’t had enough time with it yet. However given that the 770T is US$120 cheaper than the GY611 (based on Ron Lund’s prices in April ’08), you have to give the 770T some serious thought.

Overally, JR have finally produced a decent gyro whose performance is easily replicated on many different machines that is finally able to take the fight to Futaba’s range of gyros.

MA Stratus 90

The Miniature Aircraft Stratus 90 has been out a fair few years now. It’s already has a proven reputation itself as a top quality machine capable of hard 3D flight after flight. I’ve had a chance to fly a couple at various stages over the last couple of years and have always been impressed with how they flew.

MA Stratus 90
MA Stratus 90

Last year a mate of mine bought one and gave it to me to build and test. The machine would have a YS 91, Hatori 3D pipe, Futaba 9351 servos, JR 770 gyro with servo and a Fromeco regulator so it was going to be fully kitted out.

Unfortunately the build got delayed quite a bit due me moving house and being away for work a bit, but eventually it got built!

I’m relatively familiar with MA machines having owned a Tempest FAI for a while, so I was keen to see how much things had changed with MA machines.

The instruction manual I used was one downloaded from the MA website and printed. I didn’t bother opening the CD that came in the box.

The instruction manual format has changed, for the better I might add. When I was building the Tempest, there were two seperate installation manuals, one with text, the other with diagrams. This was ok, but I much preferred the layout of JR manuals that incorporated everything onto one page. MA are now doing this which I reckon is a nice improvement.

The manual also has colour images which is a nice touch.

At the start of each assembly section, the first few pages are devoted to a parts listing so you can compare what the instruction manual requires in terms of parts with what you actually have. This is a valuable exercise as missing parts from MA kits is a relatively common occurance compared to kits from Thunder Tiger and JR.

The text in the manual is nice and comprehensive and you’re not often left to wonder what the hell they were trying to say. The part that caught me out was the use of imperial measurements mixed with metric. Now I’m from the metric generation, telling me to do something 3/8’s of an inch along a shaft is going to send me on a trip to Google to find out how many millimeters 3/8’s of an inch equals. I know these are American kits, but I’m pretty confident when I say that the helicopter market is a metric market.

MA haven’t changed their approach to their drive train and that’s a good thing. While they have a unique method of transferring drive from the fan hub to the clutch via two pins slotted into rubber isolators centered by a rubber ball, I quite like the idea. It provides an element of isolating engine vibrations to the airframe which is good. However past experience with the Tempest has taught me that you need to keep an eye on the rubber isolators as they do flog out and need replacing.

The base collet in this particular example was very tight to get down the engine’s crankshaft, however I pressed it on by using the fan hub and pushing down evenly, no big deal.

The Stratus uses a rather unique method of mounting the engine to the frames. You replace the four bolts used to hold the back of the engine crankcase together with four longer bolts that bolt through a carbon mounting plate. That mounting plate then has some engine mounts bolted to it which bolt to the engine’s mounts. The finished assembly is then installed in the helicopter. Interesting design. When I first saw this design I was worried that this may transmit a lot more engine vibrations into the frames than a ‘classic’ engine mount design, however that doesn’t appear to have been a problem for existing owners.

The finished engine mounting plate is then mounted on the large bottom carbon frame through slotted holes so that the engine can be aligned correctly.

Also bolted into the base plate is the forward fan shroud mounts as well as two large front and rear frame supports that will eventually connect the top and bottom frames together. The quality of both the aluminium and carbon parts really is very nice. Very nice indeed. You can thread in the bolts and do them up nice and tight without fear of them stripping.

One thing that hasn’t changed since the days of the Tempest is the way MA do their fuel tank clunk arrangement, it’s still from the side and you’re expected to some how secure the nut within the tank while you tighten it up from the outside. I remember I struggled with this with the Tempest and once again, I struggled with it with the Stratus also. I really do prefer the JR method of tightening up the nuts from the outside of the tank, it makes it so much easier!

The tank is secured to the bottom frames by two large pieces of double sided tape as well as two large cable ties which really secure the tank nice and good. However this is where I ran into the first of many deviations from the manual. The manual said to use velcro straps instead of cable ties, however a seperate bit of paper contained in the fuel tank said otherwise. You really do need to make sure you download the latest manual from the MA website before you assemble your machine because there’s likely to be new revisions. Note that the actual fuel tank design is quite different to what is shown in the manual also.

From the looks of how things used to be with the old tank, it sure does look like the improvements yielded from the new tank are a LOT better!

Next the landing gear is assembled, that’s pretty straight forward, although you do have to drill your own set screw holes in the landing gear struts, not a big deal though.

Next the fan shroud is assembled. The dremel comes out here to cut an opening to allow the carbuettor to fit without fouling. Also, if you’re using a Hatori pipe, you’ll need to cut a small section from the side of the shroud so that the header plate doesn’t foul. It’s all pretty straight forward.

With this, the bottom frame section is complete.

Here’s another area where things deviate from what’s described in the manual, the frames. I stared at the frames in my hand for a good while trying to work out why one matched the manual but the other didn’t. It turns out that MA have decided to move the tail servo around which resulted in a changed frame design. Once I’d realised that, then we were off again.

I like that the standoffs are nicely thought out rectangular gusset rails rather than just ‘posts’. I like the rail idea as I reckon it should had a little more rigidity. I also like the fact they’re rails not ‘blocks’ so there’s no unnecessary weight being added.

The radio tray, small as it is, but still adequate is then bolted to these rails.

The main shaft bearing blocks are really nice. They’re double bearinged affairs which I really like, that way the main shaft has a lot of bearing contact area.

Once area that I’ve always really liked about MA machines is the way they setup their tail drive bevel gear systems. On an MA machine, the drive shaft that holds the bevel gear and the dog bone coupling goes right through to a bearing block mounted on the middle mainshaft bearing block. This way the bevel gear can’t ‘jump’ the tail drive’s gear during high loads. It really is good. The other benefit is once you’ve set the mesh, that’s it, no more dealing with it again even when taking the tail off. Having dealt with the pain of putting a tail back on a Vigor and realigning the mesh each time, I really appreciate this.

The auto hub and bevel gear system look the same as it was back in the days of the Tempest which is great because it really is faultless. Care has to be taken here, just as with other auto hubs to not damage the sprag bearing when inserting the center shaft.

The mainshaft is then slotted through all the bearing blocks and auto hub. The hub is then fastened to the mainshaft using a dowel pin and set screw arrangement that I like.

You then set the mesh of the tail bevel gear by sliding the bevel along the shaft slightly until the mesh is exactly right.

This particular machine came with an 8.18:1 gear ratio. Like the Tempest, the gear ratios can be easily changed by changing the plates provided with the kit and the pinions. The plate gaurantees that mesh between the pinion and the main gear is correct for the given gear ratio. Each plate is imprinted with the gear ratio it is designed for which is nice.

Carrying on from my earlier discussion about the way in which drive is transmitted from the fan to the clutch via the rubber isolators, the clutch stack consists of the adapter with the pins at the bottom below the bearing block. Above that is the actual clutch which ‘seems’ to be bigger than it was on my Tempest which if true, is a good improvement. Above this is the actual clutch bell with the appropriate pinion, the top of which is located in the top bearing block. It’s a very solid system. It’s great because it’s supported at the bottom just below the clutch, and at the top by the top bearing block. I like systems that are supported top and bottom like this, it reduces sideways loads on the top of the pinion which stops it from fretting.

There are a few plastic pieces around where plastic is appropriate, for instance the CCPM bell cranks and the anti-rotation guide are plastic which I think is fine. What I really like is that the ball links provided with the kit have a hex driver slot built into them like the Synergy. It’s a lot better than the ball and screw affair that JR use.

At first, I thought I was missing some pieces, the tail bell crank that goes between the tail servo and the long pushrod that goes down the boom. However after another check I realised the new frame change relocating the tail servo, meant the bell crank was now no longer needed.

The completed top and bottom frames are then bolted together. A bit of paitence is required whilst working the clutch pins into the rubber isolators on the fan hub as you don’t want to damage them. Once the frames are together, you can then align the engine correctly using the four bolts in the slotted holes in the bottom carbon frame.

It’s actually quite nice to be able to split the frames like that by undoing eight bolts! Infact I’m not sure, but I think to get the engine out you’ll have to take the top frames off, but that’s not a big deal.

The swashplate is the traditional MA one same as it was on the Tempest FAI. Once again the ball links have the hex slotted holes in them which is great. I did find that sliding the swashplate over the mainshaft yielded a lot of friction. A few dabs of Tri-Flow on the mainshaft and some vigorous sliding of the swashplate up and down the shaft saw it come good.

The plastic washout arms are pretty straight forward, pins with circlips are used to attach the washout links to the arms. This then bolts onto a plastic washout base. I’m all for using plastic where it’s appropriate, but I’m not convinced that washout bases are an appropriate place for it, especially for a machine priced in this range. I would have liked to have seen an aluminium base on this machine.

Watch for the washout arms fouling on the anti-rotation guide too. It’s not hard to fix, a little loosening of the guide screws while moving it before tightening again fixes this.

Tail assembly begins with the tail pitch slider. This is a pretty simple exercise, it’s mainly plastic and is held together by two retainer clips. Two nicely machined pitch links completed with assembled bearings are then bolted onto the arms of the pitch slider.

The tail blade grips bought back memories for me. I remember how much of a pain in the ass it was to tighten up the locknuts once the assembled blade grip is on the tail hub if you don’t have an appropriately sized ‘gripping tool’.

One thing that I thought was great was the fact that MA mentions in their manual to balance the tail assembly, a procedure that’s often forgotten when assembling these things, but can really save you from having to diagnose annoying tail vibrations.

I was a bit surprised to see the tail gear box was already assembled, it looks like a very simple assembly anyway! The gearbox is open so you can easily work on it which makes a very pleasant change from the nasty enclosed gear box that was on my old Tempest FAI! On that thing you had to often assemble by feel and it wasn’t great.

The plastic bell crank is attached to the gear box followed by the earlier assembled pitch slider and the tail hub. The tail hub is secured on the output shaft by a couple of unique looking grub screws which have ‘dog points’ on them which engage in dimples in the output shaft.

Assemling the torque tube is real easy. The tube comes with the bearing and dogbone already installed which is great and it slides easily into the carbon boom.

The plastic boom clamp is attached to the boom. Some may be sad to see plastic used here instead of metal, but not me. I’m a fan of using plastic here, especially on carbon booms as they grip well and are less stressful on the boom.

The gear box attaches to the boom by plastic tail rotor mounts which grip the boom and which the gear box is screwed into.

The single tail pushrod guide is then attached to the boom, the carbon push rod goes through the guide sheathed in plastic to prevent wearing (which does happen a lot with carbon pushrods).

Attaching the boom to the frames is via a plastic boom mount which slides into the bevel gear dog bone. No alignment needed!

Assembling the boom supports is straight forward, I use the usual method of epoxying the ends into the carbon tubes and attaching them to the helicopter straight away so that one support is not longer or shorter than the other. In this way they fit without stress.

MA machines don’t use push-pull arrangements on their servos, instead they use servo supports which are a good alternative. This reduces the side loading on the servo output posts and allows the servo to produce a more direct output to the control surface without moving in the frames.

Installing the servos is straight forward. The built-in threads into the frame make it very easy. The servos either bolt directly against the frame, or to the frame on top of stand-offs to set them out from the frames a little.

You need to get the dremel out again to prepare the servo horns, in this case the large circular Futaba ones. You need to cut a section off the edge of about 5mm. This is so the wheel does not foul on the servo support posts.

Once complete, the servo wheels bolt to the servo output posts using servo bearing studs which thread into the servo posts. The servo supports then attach on top of the output posts. Bearing studs for both JR and Futaba are supplied.

Carbon servo supports are supplied with bearings that attach on posts on the frame at each end of the servo.

The ball links are nice and free out of the box and requires no extra ball link reaming to achieve a smooth action.

This machine had a Tempest 3D head to go on it instead of the standard Tempest head. However it does have the head block that comes with the Tempest that has the new flybar carrier. This flybar carrier is quite a piece of engineering! The see-saw allows you to adjust the flybar ratio to three different settings.

The flybar is supported in a heavy duty cage style arrangement which I favour over the JR Vigor/Vibe’s arrangement of having a single arm for each side of the flybar. The Stratus carrier also uses two tubes that extend the see-saw, this is good because it supports the flybar more and prevents the flybar from flexing.

The rest of the head assembles in the traditional Tempest manner. The head center block is quite wide, similar to the Raptor and uses O-Rings for dampening which has become the standard dampening system for a few years now.

The Tempest heads are still unique in that the blade grip bearings, thrust bearings and spacers are assembled on the spindle shaft and bolted up and then the blade grips are pressed over the top of the assembly and bolted in. I remember this working very well on my Tempest FAI and certainly one of the blade grips on this machine went on very easily, however the other one took quite a bit of persuasion!

The blade grips following the ‘leading’ style in that the pitch arms are mounted on the front of the blade grip rather than the back like the Vibe. Following the trend of adjustability on the head, you can adjust the delta value by moving the Bell-Hiller mixers along the pitch arms. I just left it in the middle as I’ve really never noticed the difference whenever I’ve played with the black arts of delta.

Once again, the quality of the parts used in this kit really are top notch. The machining of the blade grips is very nice indeed, the parts are nice and smooth, not overly heavy and best of all, you don’t feel you’re going to strip the thread when screwing in bolts.

In recent times, RC helicopters are carrying more and more electronic equipment than they ever used to, such as regulators, governors and gyro head units among other things. Unfortunately the amount of space provided in helicopters seems to have reduced! My old Vigor has a huge radio tray with vast expanses of space to load everything onto. The new Vibe however has a lot less room. This trend holds true for many new machines on the market.

Surprisingly, the Stratus actually has a lot of room available for electronics installation. The reciever is mounted vertically on the side frames which allows the tray to be free to carry any gyro and governor head units as well as regulators and batteries. Because this machine didn’t have a governor and the gyro is a JR 770 which doesn’t have a head unit, the radio tray had more than enough space! It would be interesting to see how a machine with a ‘full compliment’ of electronics would fare space wise.

What is annoying though is the fact that there is no antenna tubing supplied, nor is there any moulded brackets in the landing gear to support tubing, so where is your antenna supposed to go? I know with the rise of 2.4ghz equipment this is becoming less of an issue, but still.

After suddenly realising that MA still persist with their unique start shaft adapter system (instead of the Hex starter adapter that is the de-facto standard) and also realising that I don’t have an MA start system, I had to take an emergency drive out to the Stratus owner’s place to get his starter. While some might argue that the MA system is superior – it may well be, I don’t really have an opinion – it would be nice for a hex adaptor to be supplied as standard instead of a seperately purchased option.

The YS fired up instantly and settled into a nice idle. The heli spooled up cleanly but was running slightly lean so I richened it up a few clicks on both the top, mid-range and also the bottom. However as I was doing so I noticed the fuel tank was leaking around the output and pressure fixtures which would also be causing part of the leanness so I shut the machine down to fix that.

Fixing the tank problems just meant tightening the fixtures up more which thanks to the Stratus’ split frame design is pretty easy. You just undo the eight bolts holding the top and bottom frames together, lift the top frames off and you have complete access to the tank.

With the tank fixed I started the heli and got it into a hover. I was immediately impressed with how stable the machine was, no vibrations and the tracking was perfect. Collective response was crisp as were the cyclics. The heli sat very neutrally in the winds, it didn’t get blown around much at all.

In forward flight the gyro wagged a little which was fixed by reducing the gain of the JR 770.

Forward flight stability was impressive, the heli didn’t want to pitch in any direction and it did large, accurate loops without pitching at the bottom.

The rudder felt a little strange simply because the standard gyro settings have a huge piroette rate which makes the helicopter tail feel non-linear.

Autorotations seemed to go on forever, the Stratus’ light weight certainly helping here.

Just as I decided to start getting into some 3D with the machine it suffered a tail failure during piroetting flips and pounded in. Pounded in good. It turns out that the boom had slipped back which had caused the loss of tail drive. A number of people I talked to later said “Yeah that’s what Stratus’ do, that’s why you have to put a bolt directly into the carbon boom”. Well I went back and checked my instructions (created 11/01/05) and there was no mention of that. However the new frames did have a bolt thread to do this. If you’re building an MA machine, always check their website for the latest instructions, cause these guys change things on the fly.

The crash was made worse by the fact that when I flicked out of throttle hold after the machine hit, I’d forgotten to take it out of Idle Up so it did a funky chicken for a bit until I could work out what had happened.

The damage wasn’t too bad, the tail section had escaped relatively unscathed, however the head area had taken a good hit, the JR tail servo had stripped as had one of the cyclic servos. The huge flybar rocker assembly made removing the bent flybar, a royal pain in the ass, plus, the potential to bend something expensive in that assembly is too great for my liking.

The machine is now fixed, however it’s now being transformed into an E-Stratus (with potentially a flybar-less head) so I didn’t get much time to form an opinion on how this particular one flew.

Overall, the machine seems to be very good, it flew (and hovered!) very nicely and it seems very strong. You definately can’t mistake it’s heritage for anything other than Miniature Aircraft in that it’s not as simple as it could be (ie lots of little carbon bits, standoffs here and there etc), a lot of these little appendages look very vulnerable to a crash. The machine is very tough though, anyone who has seen Bobby Watts fly his will know that.

The thing you do get when buying MA is that the machines are based on the same old tried and true designs of the old days. The swashplate and washout assembly can be traced back to the old mechanical mixing machines which is a testament to the design.

MA, like Align, seem to be very dynamic in that when the need to implement a change is identified, they do something about it straight away and incorporate that change in kits as they ship, hence the dynamically changing instruction manuals. Manufacturer’s like JR could take note of this.

If you’re after a 3D style machine engineered for quality then you’d have to seriously consider the Stratus, along with the Vibe and Synergy. So if you’re in the market for a machine like this, then give the Stratus some serious consideration, you won’t be disappointed.