As I get more time on the Align BlackShark there’s more tweaking and adjustment going on. Here is the latest round of modifications I’ve made to my machine to suit my tastes, and the reasoning behind them..

1) Gear Ratio

Out the box the Trex 700F3C runs a 9.33:1 gear ratio with the 470KV motor. This setup leaves very little headroom at the top end for the ESC governor to work with anything but perfect fresh batteries. This is with a Max head speed of only 1950rpm programmed into the ESC too. There are a number of options available to sort this, a change of motor or a gear ratio change. With the latter being the more cost effective that is what I went for. I changed to a 110T main gear and a 13T pinion to give myself a ratio of 8.46:1. With this ratio the ESC is happy from my hover head speed of 1570rpm right through to an aero head speed of 2050rpm with room to spare for the governor to work at its best.

2) Tail Gear Ratio

Again as standard the tail ratio is a little on the low side, just like the main gear ratio. At 1:4.33 I wanted to increase this to something in the higher 4′s. Swapping out the tail counter gear assembly and main tail drive gear allows a number of options. I went for the 21 tooth counter gear arrangement which gives me a new ratio of 1:4.95. The other option is to go for 22 tooth and have 1:4.72.

3) Flybar Ratio

Yet again, another ratio..and too low. In my previous post I talked about swapping out the ball on the swashplate side of the mixer arm to increase the ratio. With some newer more accurate measuring instruments I’ve got an accurate reading of 25 degrees of flybar tilt to 15.5 degrees of blade tilt. This gives a ratio of 0.62:1, better than standard but still far below what I would like. Fitting a set of Trex600 Pro mixer arms with  a combination of Linkage Ball B and Linkage Ball A (Complete set: HN7065). I also used Linkage Ball B in the flybar carrier (in fact this is where I got my Linkage Ball A from!), however you will need to file down the threads slightly to stop them interfering with the flybar. Using this arrangement gave me no change in overall pitch range but resulted in 19 degrees of blade movement for 25 degrees of flybar movement giving me a much better ratio of 0.76:1. I did need to add a small washer (tail rotor blade spacer) behind the mixer arm to stop the ball links from fouling on the mixer arm itself. Also this arrangement needs your servo throws set perfectly as it is on the mechanical limit of what can be achieved on the rotor head and it’s easy to get binding if things aren’t perfect.

With almost a complete week of flyable weather (shock, horror), I’ve been able to get some serious airtime on the Align Blackshark body that I reviewed in a previous blog entry. During this time I’ve made some modifications to better suit the model to me. That’s not to say the original setup is wrong, far from it, however everybody has their own personal preference on setup and this blog entry will detail the modifications I’ve made to my machine, and why.

1) Flybar ratio

The standard Trex rotor head, even in it’s highest setting, has quite a low flybar ratio. The most accurate measurement I could get was around 0.6 : 1 where as I personally prefer a setting much closer to 1:1. A low flybar ratio gives you sharper controls, however you suffer more with trim changes in the wind. My solution was to replace the ball on the mixer arm that connects to the swashplate with a lengthened ball from the swashplate. This moves the link closer to the rotor hub. The offset geometry gives a nice boost in flybar ratio. I am now just over 0.7 : 1 and the difference in flight is noticable. I can’t go any higher now with the current head design and mixer arms without things binding.

2) Flybar length

I have reduced the standard flybar length from 570mm to around 520mm. With the standard flybar the model didn’t track as nicely as it could in fast forward flight and felt slightly “balloony” on the elevator. I didn’t want to add more weight to the flybar so instead fitted a shorter flybar and cut down the flybar stiffeners.

3) Damping and teeter

Typically I like a model with a teeter point and no lead lag, which is just how the standard Trex rotor head is configured with the plastic inserts. However adding the Blackshark body I have found it hovers better with a fully floating axle. There are less trim changes in the wind with this setup. I’ve replaced the red soft dampers with the harder black damers, this is because of the increased forward speed from adding the Blackshark body. To make up the space taken by the head inserts (now removed) I have placed a standard JR o-ring damper behind the Align damper to remove the spindle float.

For completion this is my setup:

Transmitter : JR XG11

Cyclic Servos : Align 610

Gyro : Futaba GY701

Tail Servo : JR Wide Voltage MP82

ESC : Castle 120HV2

Motor : Align 470Kv

Main Blades : Radix F3C V2

Tail Blades : Radix 95mm

The Shark fuselage by Black Products Japan has been synonymous with F3C since the late 1980′s. Having graced a number of World Champion models it has stood the test of time and is still “the” fuselage for F3C flying over 20 years since its first appearance.

Black Products have for a number of years worked very closely with Hirobo, and the BlackShark body has almost exclusively been designed around Hirobo Eagles and been flown by their pilots.

Align needs no introduction, however until recently their market target audience has been nearly 100% 3D. Looking to branch out into other areas they have grown their scale fuselage range and also started to market dedicated F3C helicopters.

In 1995 on a visit to Hirobo in Japan I met a young Japanese pilot by the name of Manabu Hashimoto. He was tipped by Hirobo to be the next World Champion. Sure enough in 1997 he became World Champion. And again in 2003. His success is matched only by Curtis Youngblood and Hiroki Ito.

In a massive coup for Align they have not only managed to secure the services of Manabu Hashimoto to fly for them, but also the support of Black Products. This team work has led to the creation of the Black Shark fuselage for the Align Trex 700 F3C.

Unlike the original Black Products fuselages this one has had the Align treatment. It is available in a number of colour schemes, ready assembled and at a very competitive price. Currently the body retails in the UK for just under £500. For comparison other pre-painted F3C bodies from Japan are inexcess of £1000…

On delivery the first thing to strike you is the size of the box. It is massive. The body is assembled in one unit in the box, and the box needs to be sturdy enough to survive Parcel Force and the like. Align are certainly playing on their work with Black Products, both logos are prominent everywhere. You are under no illusion over who has been involved in the design and development of this body.

Unboxing the body reveals a beautifully painted piece of work that is honesty remarkable at the price. The paintwork is not flawless, it couldn’t be at this price. However blemishes are few and with a deep gloss the overall effect is very impressive. Certainly 1ft away and you’d struggle to spot the problems.

It’s also worth noting at this point that you get a lot more in this than just some nicely painted glass fibre. Also included in the box are:

1. New low profile undercarriage
2. Decal sheet
3. Numerous blocks of mounting foam
4. Drill and Tap and template for modifying rotor head
5. New metal and carbon fibre undercarriage mounting points
6. New low profile tail rotor gearbox

You read that correctly.. modifying the rotorhead.

The template, drill and tap are for mounting a flybar seesaw limiting screw in the head block. At first I thought this might be for flying reasons, however once the body was mounted its real intention was clear. Without reducing the flybar movement it would be in danger of hitting the rear body work section!

The Black Shark was original designed around taller Hirobo mechanics. Therefore to get the Trex to sit at the right height inside the body Black Products have designed a set of stand offs that mount to the bottom of the frames to extend the height of the mechanics.

Finally there is a new mounting block which sits on the ESC tray to secure the top of the body and the slim line tail gearbox that does away with the vertical fin mount.

The body itself is secured at the rear by the ESC bracket and the lower undercarriage plates. The front section is located with a few guide pins and securing screws. At the bottom of the front section is a strong magnet that “aligns” the body with the new undercarriage structure.

Removing the front section is as easy as undoing 4 screws and sliding it forwards. Certainly not much harder than most canopies. Removing the rear is almost as easy and the whole mechanics can be removed in about 5 minutes.

The finished product looks like something several times the asking price.. It can easily stand proudly with the most elite of F3C machines and not be disgraced.

Our beautiful British weather has reduced flight testing to a quick single flight in a water/mud soaked field!

First impressions are that the machine is quiet, smooth and tracks well in fast forward flight. Visibility is obviously excellent! I look forward to getting some more time under the mechanics to start to really stretch its legs.

To summarise, this is a very well thought out kit that goes that bit further than just providing some fancy glass work. There has obviously been some real care and attention put into the design of the fitting and packaging of the product. At this price there really is nothing available currently in the UK to compete with it. Whilst the fitting kit is designed around the Trex the original design was based on Hirobo mechanics, therefore I’d expect it to be relatively easy to adapt to other mechanics should you wish to.

Recently I’ve decided to move over from Castle controllers to the new YGE range. One thing I was going to miss though was being able to set an exact RPM in the governor mode. I like to know exactly what RPM I am doing without having to tach the model. Many ESC’s have governor modes but you have to tach the model to know what it’s really doing.

That is if you’re using the internal governor facility. If you use an external governor like that built into the GY701 the problem is solved.

I’ve been running the GY701′s for about 9 months now but hadn’t been able to use the governor function as the gear ratio didn’t go down to 1:1.. and the easiest way to use an external governor on an electric model is with the sensor reading the main gear. Happily though at the end of last year Futaba updated the firmware to allow to go down to 1:1. Therefore with my new YGE 120HV in hand I ordered up a Futaba GV-1 sensor and magnet pack.. oh and the USB cable to update the GY701.

With everything fitted I ran through the calibration sequence and turned the governor mode OFF on the YGE itself. I set the GY701 to analogue servo and everything else as default.

On the transmitter I dialled in 1500rpm for hovering and 1975rpm for aerobatics. On the hover setting I enabled the slider on the side of the transmitter and set it to +/- 200rpm. This way I can tweak the RPM up and down in the hover if I want without upsetting the aerobatic RPM.

The first flight was a complete non-event. The machine came up to speed and settled to its target RPM nicely. Moving the slider up and down in flight proved the GY701 was governing properly. Off into the aerobatics and the machine ran smooth with no hunting or obvious over-speeding.

YGE + GY701.. will it work? Definitely yes!

Happy days.

One thing that stopped me from jumping on the 12S electric band wagon at first was the thought of relying on electronic components from not firing the machine up at full power when I plug the batteries in… and there being no clutch… and having to have both hands on the connectors rather than the rotorhead. Being a software engineer I also appreciated that bug free software is impossible!

I may be over dramatising a little but these were real concerns of mine. Having been bitten by an old Voyager E on NICADS I certainly didn’t want to be on the receiving end of several horse power of angry carbon fibre!

I stumbled across the Emcotec Safety Power Switch whilst researching solutions to this issue.

Widely used in large fixed wing F3A aircraft it is designed to isolate the power supply whilst you connect it. Once ready you can remove the magnetic pin with one finger to let the power flow.

Not the cheapest of solutions, but worth every single penny.

And of course available from Midland Helicopters!

After a good 3 years of solid abuse and crashing (thanks Steve…) I felt the Winter time would be a good a time as any for a thorough overhaul of the little Rave 3D. With a new motor, canopy and servos I wanted to swap it over to flybarless. With CYE out of stock of Total-G’s I was on the hunt for a stop gap and decided to give a Thunder Tiger GT5 unit a spin (pardon the pun!).

The initial reports and reviews I found on the web didn’t inspire me with lots of confidence that I had made the right decision, but undeterred I thought I’d give the little unit a chance!

First up the touch interface is novel, pretty and useful when you don’t have  a laptop handy. However I don’t have big hands and even I got a little frustrated now and again tapping away on it! I kept all the values at default to start with and soon had the machine ready for it’s first flight.

Which didn’t go well.

My prime suspect was the piro-compensation being in the wrong direction (not something you can really check on the ground!). A quick play in the menus reversed this option and I tried again.

Success!

Things were much happier now and the model felt much nicer to fly. At this point I upped the gain on the transmitter to 90%.. and then gave up with any more setting up as I was having too much fun flying it! Piro flips, piro loops, hurricanes, axial rolls.. all tracked well and the model felt very natural on the controls. Some flybarless units look and feel very digital in flight but this had a nice balance between a flybarless and flybarred feel to it. This feel is adjustable in the menus but I personally found the stock value a nice balance and am not inclined to change it.

Now one comment here I will make which I hope will help others with this unit (and stumped me for a bit to be honest) is that whilst the gyro gains for the cyclic and tail rotor are separate on the unit they are linked on the transmitter. For example, if you set the cyclic gain at 50% and the tail gain at 60% on the unit and increase the unit gain by 2% on the transmitter then the cyclic will go to 52% and the tail to 62%.

At first I thought this was infuriatingly mad.. however thinking about it some more it does make sense to a certain degree. Once you’ve found your optimal gains the chances are that they cyclic and tail gains will need to be varied by the same amount with changes in rotor speed. Therefore why change them individually when you can change them all at once? You could even mix your gain channel to your governor channel on your transmitter so that your gains track your headspeed.. cunning..

As a matter of note my gains I’ve left at stock and am running at 90% on the transmitter. The system could go higher but as the model is flying so nicely I’m not going to touch anything!