RC-Soar's Blog

Cockpit SX M-LINK goes F3F

2012-01-21T04:54:00.005Z

As we roll into 2012, I'm at last migrating my F3F models from 35 MHz to 2.4 GHz. Yep, it's time to recognise that the world is changing, and most other R/C disciplines have already done the switch. And it may seem a little thing, but having a tiny little aerial in place of the enormous 35 MHz fishing rods will make it easier to negotiate the heather, rocks and rabbit holes which always crop up when least expected!

The first to get the M-LINK facelift is my Sting. Out goes the 7 channel Micro IPD receiver, and in its place is a RX-7-DR device. I chose it over the DR 'light' because it has higher sensitivity as well as built in telemetry of voltage and signal quality. Controlling this little lot is my Multiplex Cockpit SX M-LINK transmitter.

Cockpit SX M-LINK goes F3F'ing

I was careful with range testing as the model has carbon wings. With the model pointing directly at the transmitter, range was well over the recommended minimum of 100 meters. With the model pointing away from the transmitter, however, range dropped to 80 meters due no doubt to the wing. Before the first flight I set the failsafe to deploy 20% spoiler, in order to provide a visual warning of any range issues.

Well so far I've completed two flying sessions with the M-LINK system installed. Both were completed without a hitch, even with the model flying out well away from the slope. However it wasn't particularly thermic so ultimate range checks will have to wait another day.

A word about the radio... some of you may know that I'm a great fan of the original Cockpit SX. With few changes (apart from the rf link), it's no surprise that the M-LINK version is also a joy to programme and use. The new version also benefits from more model memories (18). Any complaints are pretty minor, the main one being the tendency for the transmitter to tip up when using a neck strap. Balance without the neck strap is fine though, and it remains a splendid radio for discus launch gliders. The other slight niggle is that the glitch logging is a bit rudimentary - you can get a glitch count by counting LED flashes, but it doesn't tell you anything about the time or duration of each event.

M-LINK receiver now installed in the Sting

Back to the Sting... another test session will be needed in thermic conditions before the M-LINK installation can be considered permanent. At that point I will purchase an M-LINK module for my mc4000 (this being my primary F3F radio).

Designing a transmitter setup for F3F

2011-10-21T22:56:00.001+01:00

[See also discussion thread on BARCS forum]

I love F3F, it's fast, competitive, and fantastic fun. The format is very simple, yet to do well requires skill, concentration, and many hours of practice.

F3F is also pretty demanding of the radio control system. On one hand, the transmitter should be simple to operate in the heat of competition. On the other hand, it should allow the pilot to make key adjustments safely, without having to land each time.

In this post I'll review the main features to look for in a transmitter and describe my approach to programming advanced sets like the Multiplex mc4000 and Futaba 12FG. I'll also describe some useful functionality which I've implemented on my mc4000.

The focus of the article will be on features and ergonomics (in the broadest sense) rather than the details of programming.

Making adjustments often means landing the model first

Transmitter Checklist
OK, let's look at the kind of stuff your F3F transmitter needs to support, and why.

Wing servo mixing
Different manufacturers have different ways of specifying F3X support, however, it really all boils down to eight key mixes for the wing servos:

Roll

Aileron stick -> aileron servo
Aileron stick -> flap servo

Butterfly (brakes)

Spoiler stick -> aileron servo
Spoiler stick -> flap servo

Snapflap

Elevator stick -> aileron servo
Elevator stick -> flap servo

Camber control

Flap lever -> aileron servo
Flap lever -> flap servo

The best way to check for these mixers is to borrow a tx and start programming. For example, the Spectrum DX-7 only has seven of the requisite eight mixers, which isn't obvious until you actually try programming it.

Tail mixers
Similarly, five mixers are needed for the v-tail:

Elevator stick -> tail servo (pitch)
Rudder stick -> tail servo (yaw)
Spoiler stick -> tail servo (trim compensation)
Flap lever ->tail servo (trim compensation) [useful but not essential]
Aileron stick -> tail servo (for 'coupled ailerons and rudder' aka. 'combi')

Enough about mixers, let's move on to...

Flight modes

Flight modes are essential for F3F. They enable the pilot to switch quickly between different sets of settings for trim, travel, differential etc. Flight modes are usually selected via a three position switch, so they need to be mutually exclusive. An easy way to ensure this is to map them to temporal phases of flight e.g. 'launch', 'speed', and 'landing'. Flight modes are available on most mid-range sets.

High end sets usually offer more than three flight modes. For F3F applications, a fourth flight mode can come in handy for reflex (explained in more detail later). In this case, two or more selection switches will be needed used. To resolve conflicts when more than one switch is used, flight modes are assigned priorities (MPX mc4000 and Futaba 12FG).

Mixer interlocks
In general, different flight modes require different mixers. Ideally as you switch flight modes, the appropriate mixers will be activated automatically. If your tx does not support this (and most mid-range sets don't), then you will need to define separate switches to handle the mixers. This is bad though - fiddling with redundant switches only serves to addle your brain when you should be concentrating on flying!

Adjustment sliders
Fiddling with the programming menus whilst flying is something we've all done, but it's not a good idea for obvious reasons. One solution is to program your Tx so you can adjust key settings directly, via spare knobs and sliders. Doing this can radically speed up the trimming process, and also reduce wear and tear on the model, by reducing the need to land each time.

Ideally, your transmitter will have three or four sliders assignable to useful things like snapflap volume, differential etc. In practice, this facility is only available on high end radios, and with varying degrees of usefulness.

Aileron Differential Suppression
In order to maintain roll response during the landing approach, it should be possible to cancel aileron differential as the brakes are deployed. Some radios provide this by default. Others (like the mc4000) require you to program it explicitly.

Key features of my Multiplex mc4000 setup
You could say this post has been a while in coming - I've been flying F3F with the mc4000 since 2001, and have been refining the setup ever since. My goals have been pretty consistent during this period:

Minimise the number of switch operations during a competition flight
Enable key settings to be adjusted in flight

The main features of the current setup are as follows:

Three flight modes
Intelligent 'reflex' option
In-flight adjustment of:

Snapflap volume
Snapflap exponential
Aileron differential
Camber

Hedgehog-o-phobia
I prefer a minimalist control layout :-)

Simple control layout on my Multiplex mc4000 (click to enlarge)

Notes

Tx is 'mode two', i.e. aileron and elevator on the right-hand stick.
Although there appear to be four sliders, only the outer sliders are functional on an mc4000 - the inner sliders are just place-holders.
The rudder and spoiler trim levers have been reassigned as adjusters for aileron diff and snapflap volume.

Flight modes
For my F3F models, I used to use three flight modes. However, having discovered the wonders of flight mode priorities (also available on the Futaba 12FG), I now use four flight modes controlled by two switches. It may sound complicated, but it's actually very simple as only one of the switches needs to be operated during the flight.

The four flight modes are:

"Landing" - landing
"Normal" - speed run
"Reflex" - speed run, with reflex
"Launch" - launch and thermal seeking

Flight modes are controlled by switches T1 (3-position) and SW2 (2-position). The up and down positions of switch T1 select Landing, and Launch flight modes respectively. The middle position (for the speed run) selects either Normal or Reflex depending on the position of SW2.

T1 - up : LANDING
T1 - middle: slaved to SW2

SW2 - off: NORMAL
SW2 - on: REFLEX

T1 - down: LAUNCH

Reflex mode is typically selected via SW2 before the flight and then forgotten. During the actual flight, the pilot need only operate the main mode switch (T1). Furthermore, the pilot only needs to flick the switch twice during the whole flight - once before entering the course (launch to normal/reflex), and again for the landing approach (normal/reflex to landing).

On the mc4000 and Futaba 12FG, flight modes are assigned 'priorities', careful choice of which enables the two switches to interact in the manner described above.

Mixers
My mc4000 is programmed so the correct mixers are automatically switched in according to the flight mode. The mixers are as follows (for each flight mode):

"Landing"

spoiler enabled
snapflap off
camber preset off
reflex off

"Normal"

spoiler off
snapflap enabled
camber preset off
reflex off

"Reflex"

spoiler off
snapflap enabled
camber preset off
reflex enabled

"Launch"

spoiler off
snapflap off
camber preset enabled
reflex off

Restoring snapflap movement when reflex is enabled

Something which has cropped up on the forums is how to retain maximum snapflap movement when reflex is enabled. I've done this quite simply on the mc4000, by varying the amount of reflex according to the position of the elevator stick. With the elevator at neutral, there is maximum reflex. With the elevator stick fully back, reflex falls to zero, allowing the full effect of any snapflap to be restored.

In-flight adjustment via sliders
Up to four key parameters can be adjusted using sliders and trim levers. These are as follows:

1. Aileron differential
2. Snapflap volume
If you have read Kevin Newton's splendid guide to Setting up a Racing Glider, you'll know that the two key adjustments for an F3F ship are (a) aileron differential and (b) snapflap volume. I've therefore programmed the mc4000 so that these two adjustments are assigned to the left hand trim levers.

3. Snapflap Expo

Snapflap expo is an extremely useful adjustment - it allows you to optimise the 'ping' in a racing turn. As far as I know snapflap expo is not available out of the box on any transmitter. I implemented it on the 4k by creating a mixer with two elevator inputs, one linear and the other exponential (using a 13-point curve). The two curves are blended, with the result weighted to one or other curve according to the position of the slider (slider F in the photo).

4. Camber
If you look at the control layout (above), slider E is unused. This could have been assigned to another adjustment, e.g. camber deflection in Launch mode.

Summary so far
Let's take stock and judge whether my goals have been achieved:

Minimise pilot workload
Yes, a complete F3F competition flight may be flown using the two sticks and a single 3-position switch, with just three switching operations during a typical competition flight.

Facilitate trimming
Partially. With four in-flight adjustments, I've made the most of the physical controls available on the mc4000. However it would be nice to have more adjustments. A bank of say eight sliders on the front face of the tx would be perfect, allowing virtually all trimming to be accomplished without landing. (the CG adjustment might pose a problem, but no doubt somebody will solve that!). The result would resemble an audio mixing desk - rather appropriately I think.

mc4000 mixer schematic
For mc4000 owners only, below is a schematic showing the mixer configuration on my setup. Note that it uses the maximum of five multimixes per model - this program is stretching even the mc4000's capabilities.

Mixer schematic for the Multiplex mc4000

Programming this setup takes some time, conversely making adjustments on the field is very easy. All the important mixer curves - e.g. spoiler compensation - are adjustable from a single menu point, even where multiple servos are involved. This also makes it easy to experiment with multi-point (5,7,9 or 13) point curves - nine points are useful for spoiler compensation, and all thirteen are needed for the snapflap expo adjustment feature.

More info on advanced mc4000 programming technique in the Multiplex Clinic. One can only hope the forthcoming 4000 replacement offers similar flexibility, but with a more modern programming interface.

Other RC systems
Some time ago, I reviewed the Futaba 12FG and tested it out by programming my Sting, with the same goals in mind as when programming my 4000. The upshot is that the 12FG is capable of reproducing most of the functionality described above, with the notable exception of the slider for adjusting snapflap expo.

Nevertheless, I found the 12FG a little awkward to program, in particular, defining and modifying curves is quite laborious, as the process has to be repeated for each servo (there is no counterpart to MPX's 'multimix'). You can read the review here.

It's worth mentioning that you don't have to use high end radio gear for F3F. In particular the Multiplex Cockpit SX has all the required mixers. It's also very easy to program, and I've used it to fly my Sting with no problems. However being a cheap set, it inevitably has some limitations: you can't activate flight modes and mixers via the same switch, you can't make adjustments except via the programming knob, you can't disable the spoiler, and you can't define your own mixers.

The Multiplex Royal Pro sits somewhere in between the Cockpit and the mc4000. The pilot can adjust up to two settings in flight, using dedicated rotary knobs. You can also define your own mixers and curves. There are a couple of annoyances though, chief of which are the 'global' mixers, and the limited programmability of the 3-position switches.

Summary
Hopefully this article will get you thinking about the wider challenges, as well as possible solutions, involved in programming an F3F model effectively.

Multiplex Cockpit SX in Hahnenmoos

2011-09-25T18:51:00.000+01:00

My blog has been a little quiet, so let me bring you up to date.

In August I spent a fantastic stag weekend in Hahnenmoos in the Swiss alps with a group of F3F flyers from the UK and Switzerland, all at the kind invitation of our Swiss F3F flyer friend Stefan Bertschi.

Hahnenmoos is a fantastic site - the scenery is amazing, the slopes are varied, and the Alpine lift is quite different to anything we're used to in the UK. Quite eye opening really.

Hahnenmoos - DS ridge, front-side flying

The trip also provided the ideal opportunity to test my new Cockpit SX M-LINK. I'm a great fan of this radio in 35 MHz form, and the M-LINK version would provide all the cool glider programming without the worry of learning frequencies in a foreign language. As it turned out, going with 2.4 GHz turned out to be a good decision, as several slopes were in use simultaneously, which would have been a bit inconvenient with 35 MHz.

It was all change with the camera as well. I decided to leave the Pentax behind and take a compact camera instead. The problem with compact cameras has traditionally been their so-so image quality, but they've improved by leaps and bounds in the last 18 months. And I'm pretty happy with my little Olympus XZ-1 despite one or two handling issues (like a lens cap which stubbornly refuses to stay on). To get decent results you have to nail the exposure accurately and shoot at the lowest possible ISO, but get it right, and you're rewarded with splendid prints up on A4. More photos of Hahnenmoos on the RC-Soar.com gallery.

Hahnenmoss through the lens of the Olympus XZ-1

Back in London, I finished off a review of the Multiplex GPS telemetry sensor. This is the latest, biggest and thirstiest of their range of sensors for M-LINK receivers. The review to appear in RCMW. Suffice to say that it does what it says on the tin, and we had a lot of fun putting it through its paces at La Muela - the 'we' being myself and Kevin Newton, as it's a bit difficult for one person to control the model, take photos and read the telemetry!

Multiplex GPS Sensor

The review will also contain a section on the Multimate, a cleverly designed hand-held programmer/reader for Multiplex's expanding range of 'smart' accessories.

Multimate programmer/viewer.

The reviews are due to appear in the December or January edition of RCMW [note 3/1/11 - publication has been delayed].

Multiplex web site changes

2011-08-23T21:56:00.021+01:00

Multiplex appear to have done a big revamp to their web site, which has a new more modern look. The site does have a few issues though - it seems painfully slow at times, and the content of the English version is incomplete.

Among the content missing from the English section are the USB drivers for the data cable (#85149). These drivers are required by the Launcher program. If you can't find the USB drivers in the English version, just dip into the German version and you'll find them there.

iCharger 106B - impressions

2011-08-03T00:36:00.086+01:00

A few months ago, I decided to replace my aging Schulze 330d charger. In truth I never really liked it - poor menu navigation and a lack of flexibility made it frustratingly awkward to use. I also wanted something with a built in LiPo balancer.

After a bit of research, I settled on an iCharger 106B Plus. This is a compact 12V device, which is capable of charging a 6S Lipo pack at 10 Amps, and has an integral balancer. For the full spec, see the information thread on RC Groups.

An order was duly placed with Giant Cod, and it arrived soon after.

iCharger 106B+ with home made adapter leads

Five months later, I'm glad to say I am pretty happy with it - well, mainly. The user interface is well thought out, with comprehensive charging options, sensible default values, and not too much opportunity for error. Compared to the horrid interface on the Schulze, the iCharger is a revelation. The ability to save and load configurations is particularly useful.

There are a couple of niggles though. First, the lead-acid programme is not working on my unit - the display becomes garbled for some reason. I suspect it's a firmware issue, but unfortunately I can't re-flash the firmware because of another issue: the supplied USB lead turns out to be non-standard, even though externally it looks like an ordinary lead. This is really annoying, as the first thing many people do with new USB leads is toss them into a pile. If you lose the special lead, as I have done, it's impossible to flash the firmware.

The balancer port accepts JST-XH connectors. As I don't want to use an adapter board, I am replacing the connectors on my existing batteries with the appropriate JST-XH plugs. These leads are normally impossible to obtain separately, but my friendly local model shop gave me some discarded packs with the requisite JST-XH leads. I've started recycling these for use in my own packs. (Disclaimer: any soldering or lead-cutting on a Lipo pack needs very careful planning and execution, for obvious reasons!).

Various adapter leads

2.1 mm DC power connectors, available from Maplin. Good for around 4A.

Unboxed! The Cockpit SX M-LINK

2011-07-26T22:19:00.124+01:00

As promised, some photos of the 'unboxing' of my new Cockpit SX M-LINK.

First I should explain that the 'Action' which I bought last week had to be go back to the shop - the trims were malfunctioning due to a hardware problem. As West London Models had no more Actions in stock, I exchanged it for an 'Elegance' instead.

Well I reckon the Elegance looks incredibly smart - dare I say, super elegant - with its dark blue, semi-matt finish. The surface has a non-slip texture (something between rubber and velvet) which will make it great for DLG'ing on a hot day. However I'm not sure how easy it will be to keep clean, especially if it gets oily - the high gloss finish of the Action might make it the better choice for i/c powered models.

The Cockpit SX is available in various bundles. Mine is the 'M-LINK Telemetry Vario' set which includes a seven channel telemetry receiver. First impressions are very positive. The binding procedure is quick and simple, the sticks work smoothly, and the whole thing feels solid and well screwed together.

Incidentally, I've just been testing the battery duration of the transmitter... from full charge, it's been going 11 hours and still has several hours of juice left!!

Enjoy the 'unboxing'!

The, er, box! The 'Classic' version is shown on the cover, but inside it's another story...

Instruction manual + M-LINK addendum, stickers, safety notes, and international. frequency tables

Lots of empty space... top left is the receiver, the other two bays are for stalks and removeable antenna. Note the lack of reflections from the semi-matt finish. Whether you can see the colour of the Tx will depend on the accuracy of your display, it is actually a very deep blue.

Hardware: tx, RX-7-DR rx, four pairs stalks (plastic), one pair stalks (turned aluminium). No charger or charging cable are supplied (good in my view, as many will already have these).

RX-7-DR has dual receiver circuits, plus built-in telemetry of rx voltage and signal quality.

The multilingual manual is splendidly complete, puts others to shame. A4 format, English section is 82 pages.

A page from the helicopter section

My Multiplex Cockpit SX. It's in there, somewhere!

2011-07-23T22:59:00.102+01:00

Let me introduce you to my latest R/C system. Yes, I know you can't tell from the photo, but take it from me, it is bright yellow, and it has one of those diddy little aerials which mark you out as a thoroughly modern modeller!

Somewhere in there is a Cockpit SX M-LINK transmitter

It's my new Multiplex Cockpit SX, Action Edition, in not-quite-unwrapped state!

A word about the brown paper packaging. It was conceived and constructed by the guys at West London Models, so I could carry it on the tube. I'm pleased to report that it survive the rigours of London Transport admirably.

Photos to follow in due course. In the mean time, a bit of background. Although I've reviewed several 2.4 GHz systems and flown many dozens of hours with them, this new radio will be the first such system I've actually owned. This may come as some surprise, but most of my flying is with F3F racing gliders, and the benefits of 2.4 GHz are less clearcut here since the models tend to contain a lot of carbon, which makes installation more critical. The entry lists for F3F competitions shows that I'm not alone in persevering with 35 MHz - there's still a roughly 50/50 split between 2.4 GHz and 35 MHz users.

So why am I choosing this time to start converting to 2.4 GHz? A couple of reasons. First, I'm in the middle of converting a 48 inch STOL to electric power, and this model really will benefit from 2.4 GHz. It will be used on a crowded field, it doesn't contain any carbon, and as we all know electric motors and 35 MHz don't always mix. The second reason is that Multiplex have recently released the RX-5 Light and RX-6 Light micro receivers. Once installed in my Longshot DLG, their short aerials will reduce overall weight and drag, providing an actual performance benefit.

I will write some more words on this radio in due course, focusing on the differences from the 35 MHz version, so stay tuned. In the mean time, if you want to know a little background (based on the splendid 35 MHz version), then do have a look at Cockpit SX pages at my Multiplex Clinic.

Cockpit SX 2.4 GHz - new variants spotted

2011-06-25T23:55:00.019+01:00

Last weekend, at the Wings n Wheels model show, I finally got to see Multiplex's newly launched Cockpit SX variants, the 'Elegance' and the 'Action'.

The Elegance is nicely understated, with a semi-matt deep blue/mauve finish. It has a non-slip feel.
The Action is much louder, with a smooth deep high-gloss yellow.

Both are drop dead gorgeous. I've already reserved my own yellow one in the next consignment from West London Models!

Cockpit SX 'Elegance' (left) and 'Action ' (right)

Also on show was the Multiplex M-Link Trainer Stick - a neat wireless replacement for the usual buddy box lead.

'trainer stick' dongle

Spektrum DX10t - Beauty or beast?

2011-06-25T23:04:00.066+01:00

This weekend I should have been flying at the F3F Nationals in Wales, but a last minute commitment on Sunday forced me to withdraw. Every cloud has a silver lining though, and I was at least able to visit the annual 'Wings 'n Wheels' model show on the Saturday, where I cast my eyes on the new Spektrum DX10t.

The DX10t is quite a departure for Spektrum. It was developed primarily for the German market, hence the 'Euro' style which is optimised for thumb and forefinger flying. No separate tray is necessary since, by positioning the sticks close together, the designers have left lots of room either side for the hands.

An interesting feature is that you can plug in different modules for different applications. Each module contains 'optimised switch layouts', and the potential to use 8 extra switched channels. I didn't get to see this demonstrated, but it could be useful if you intend to use the same transmitter for widely differing applications (modules are available for fixed wing, helicopters, boats and ground vehicles).

(Incidentally modules are nothing new - they were available on a few high end sets during the 80's. The concept quietly died as most of their custom features were emulated in firmware. See the Multiplex Profi 2000.)

Spektrum DX10t. Note neck strap brackets retracted at bottom of case.

The transmitter uses a Lipo battery and integral charger with 12V input. Yes, that's right: the charger is built in to the transmitter. Is this a good idea? Having an integral charger avoids the possibility of setting the wrong Lipo parameters, but you lose the flexibility provided by a separate charger, and you also need to find a 12V power supply.

The Specktrum DX10t supports both DSM2 and their new frequency hopping DSMX. While I didn't have a chance to play with the programming, what I saw from a brief run through looked promising, and certainly different in style to the DX-7.

As to the styling, well... opinion on the forums seems to be sharply divided, with some approving of the 'retro' look, while others claiming that it's... well... pig ugly. I have to admit to being in the latter camp. Not to put too fine a point on it, I think it looks ghastly - rather worse in the flesh than in the adverts. The finish isn't particularly nice either, with acres of cheap, un-textured plastic. And finally, the absence of any kind of contouring on the back makes the Tx uncomfortable to carry around, except when it's round your neck.

Nevertheless, if you're looking for a lightweight Euro style transmitter, and are prepared to put up with the 70's styling and standard of finish, the set may be worth investigating. More info from the Spektrum site

Loosening the shackles of Windows

2011-06-15T13:56:00.059+01:00

Having been spent much of my professional life dependent on Microsoft Windows, it seems odd to start doubting its utility. Yet with the popularity of Mac and Linux, not to mention upstarts like Android and Chromium OS, the options are widening. For me, this comes as good news.

So what's the problem with Windows? In a word, the restrictive licensing which ties my copy to my hardware.

Hardware shackles
Like most users, my computer came pre-installed with Windows, and has an OEM license which ties my my copy of Windows to the actual hardware on the PC. If my PC were to develop a fault which required a replacement motherboard or drive, there is no guarantee that Windows would run even if the replacements were identical. In that case, the only solution would be to purchase a brand new copy of Windows.

Unfortunately, Windows XP is no longer available, so an upgrade to Windows 7 would be necessary. However Windows 7 is not a good solution as it doesn't support all my current hardware.

OK, so let's forget the doomsday scenario. Say I just wanted to do a plain reinstall of Windows, perhaps to deal with a virus, or a disk corruption. As is normal these days, my PC did not come with a Windows recovery CD. Instead, I would have to perform a System Recovery off a hidden recovery partition.

Well, I really don't like being dependent on hidden partitions. The partition lives on the same drive as the active copy of Windows, and is just as susceptible to physical damage.

Enter Ubuntu
In an effort to regain some control over my IT affairs, I've been casting an envious eye over to Linux. It's free, has no restrictive license. So I can keep it running for as long as my hardware lasts, and if my hardware breaks down, I can restore to alternative hardware no problem.

Now, it's been a while since my last experience with Linux, and I'd heard that things had improved with the recent distros. Ubuntu seems the most popular flavour, so I downloaded the iso image, burnt a CD and installed it on my spare AMD Athlon machine. Ubuntu had no problems detecting the hardware and installing the appropriate drivers. Connecting my network printer was also straightforward.

Ubuntu 11.04 comes with LibreOffice which is a perfectly functional replacement for MS Office. Out of interest, I prepared a presentation for my photography club, using Impress. I had no problem viewing it using a Powerpoint viewer. As a bonus I was able to generate PDF's directly within Impress. (The only real disappointment was Base, which doesn't really compare with MS Access.)

Backup
Ubuntu includes a variety of backup and partition tools available like PartImage, GParted, DD etc. This makes it possible to tailor your own backup strategy at both the partition and file level.

Ubuntu also comes with a Terminal Services client for remote controlling a Windows PC. This opens up some interesting possibilities in terms of re-using older hardware as a remote Windows client.

Long term
Ubuntu may not be quite as polished as Windows, but has two great things going for it: (a) there's a huge amount of good free software available and (b) it gives me back control. While I will still use Windows, Ubuntu is is firmly installed on my second machine and I'm going to have a lot of fun exploring its capabilities.

Mini Lipo Regulator

2011-06-15T12:03:00.087+01:00

[Update 01 July 2011 - PLD-BAC-55 (5.5V), and 5.5V PLD-ESJ6 are subject to a recall notice - the low voltage alarm does not work correctly. I cannot give it my whole hearted recommendation until this is fixed.]

Finding reliable NiMH battteries for DLG models is not easy. Eneloop type (low self discharge) batteries are not available in the small sizes we use, and the regular NiMH cells are not always very reliable. I've purchased a number of packs with open-circuit cell voltages below 0.8V, indicating that they've been stuck on the shelf for months if not years. Packs delivered in this condition will never reach anything like their rated capacity so the kindest thing you can do for your model is to bin them.

One notable exception has been Kan cells. I've had a couple of their 350 and 400 mAh packs and they've lasted a couple of years each. (Incidentally, Kan are the only manufacturer I know who print the manufacturing date on the sleeve, making it more difficult for dealers to pass off stale stock.)

Unfortunately the supply of small-capacity Kan cells appear to have dried up here in the UK, so when my last pack finally gave up the ghost, I decided to forego NiMH cells, and look for a Lipo + regulator solution.

After a bit of reseach on the net, I alighted on the Hyperflight web site which specialises in DLG and electric items. Twenty-four hours later I found myself in possession of:

Lipo battery: Rhino 360 mAH 2S
Regulator: 5.5 V Lipo linear regulator + LED flashing meter + low voltage alarm.

The old: Kan 400
The new: Rhino 360 Lipo + 5.5V regulator

Installation
The combination of battery + regulator take up a little more space compared with the old Kan pack. However the new combo is actually a little lighter at 27 g (21g for the battery, 6g for the regulator) compared with 33 g.

LED voltage readout
The regulator incorporates a high power LED which flashes the battery voltage. Long flashes for the number before the decimal point, then short flashes. So for example 8.1 volts is: FEEP FEEP FEEP FEEP FEEP FEEP FEEP FEEP... FIP. It's an easy way of checking the state of the battery both before and during a flying session (the flashes are easily visible through the slightly translucent fuselage of the Longshot). [Note: with units affected by the firmware bug, it's the only - albeit perfectly satisfactory - way to check the battery voltage].

Audio alarm
An audio alarm sounds is supposed to sound when the battery voltage dips below 7V. Unfortunately the firmware on my unit has a bug, and the alarm does not work as it should (it only sounds when powering up with an already depleted battery). I will update this section once the unit is fixed.

Goodbye Nims
Firmware bug aside, the lipo battery + regulator has worked very well for me. It's a little more awkward to install, but (a) no need to scrabble around for small NiMH packs, and (b) the low voltage alarm (with newer firmware) will be a useful safety feature. The regulator is of the 'linear' type, and I have had no Rf issues using my 35 MHz Cockpit SX.

And of course Lipo cells have a low self-discharge rate, so you can carry a spare pack without worring about constant topping up.

Finally, Hyperflight have been pretty good at getting stuff to me quickly on the two occasions I've ordered, and their tech support is good too. I place a high value on good support when it comes to stuff which keeps my models flying safely.

Dogfight double: Jeti Duplex and Multiplex M-LINK

2011-02-07T01:25:00.056Z

With all the talk about Multiplex's M-LINK telemetry system, it's easy to forget that it was another manufacturer, Jeti, that was first to market with a reliable bi-directional 2.4 GHz system. In fact M-LINK and Jeti's Duplex system are very similar - so similar that's it's hard to believe that Duplex wasn't in Multiplex's minds when they were designing M-LINK. Both systems permit the design of small telemetry-capable receivers, with the option of programmable external sensors. And both systems work very well.

Yet despite their head start in the underlying bi-directional comms technology, Jeti have been hampered by the lack of a telemetry-enabled transmitter. Their plug-in rf modules provide only audio feedback, and in order to view telemetry data you have to buy a separate 'Jetibox'. Another thing to charge up and take to the field....

By contrast, despite being somewhat late with M-LINK, Multiplex were able to hit the ground running with telemetry output going directly to the display of their Royal Pro and Cockpit SX M-LINK transmitters. Multiplex have also done a good job at marketing the system, with full page adverts in the model press, and their catalogue is a model of simple concise English. Documentation is also of a consistently high standard. As an overall package, M-LINK is the more polished.

Is this about to change? Because the news is that Jeti are due to launch a couple of transmitters later this year. Very interesting they look too, and no doubt some people will be holding off an M-LINK purchase until these transmitters are available. The new sets appear to be aimed at the premium end of the market.

Technicalities aside, I hope Jeti can get their marketing sorted out here in the UK, though it has to be said that the signs are not too good. My attempts at obtaining information from the UK distributor were not very encouraging, and the Jeti web site is a mish mash of Czech and half translated English. A properly structured multi-lingual web site should surely be a priority for a company about to launch a premium product.

There is also the question of support. Multiplex have a reliable service agent in the UK, with good links to the factory in Germany. In contrast, Jeti are distributed by Ripmax whose record on supporting high end R/C systems seems to have declined over recent years.

Nevertheless, it has to be said that Jeti's 2.4 GHz receivers and sensors are considerably less expensive than the M-LINK equivalents. It'll be interesting to see if Jeti's new transmitters can match the programming elegance of their Multiplex counterparts.

The new transmitters are shown here:
http://www.jetimodel.com/index.php?page=article&id=16

Some thoughts on the latest Multiplex releases

2011-02-04T13:12:00.026Z

Those clever chaps at Multiplex must have been working pretty hard recently, judging by the number of M-LINK 2.4 GHz products launched at the Nuremberg Toy Fair. Some interesting/curious/cool things which caught me eye:

A trainer/pupil lead. Except, it's actually wireless, using M-LINK dongles instead of a cable. Now, how cool is that!
Compact telemetry capable receivers (RX-5 and RX-7 M-LINK). These only employ a single receiver circuit and antenna (hence lack of 'DR' moniker). Voltage and LQI telemetry are built-in however.
Telemetry-capable RF modules and telemetry displays for Multiplex mc 4000 and JR transmitters.
Telemetry-enabled speed controllers.
Cockpit SX available in different colours (I want the yellow one!)
GPS telemetry sensor. Outputs speed, altitude and distance.
Latest v 3.04 firmware for Cockpit SX provides 18 memories and 8 telemetry lines.
High voltage servos. At last, a basic airborne system can be driven directly by a single 2S lipo.
SRXL data available at B/D socket for compatibility with Microbeast and SM Powerbox products.

Just taking a step back, what really strikes me is how well thought out and integrated the M-LINK telemetry is. Of course all this would not matter a jot if the basic link wasn't robust, but as far as I'm aware there haven't been any reports of issues, and I have looked pretty hard.

Things are looking up for Multiplex! Read more in their 2011 catalogue.

Multiplex at Nuremberg

2011-01-28T10:20:00.011Z

Amidst all this talk of gloom and doom with the economy, I've been told that Multiplex will be cheering us up with the release of some interesting M-LINK goodies at Nuremberg.

Multiplex are also supporting third party manufacturers who wish to incorporate M-LINK telemetry in their products. For anyone interested in R/C, and in particular for Multiplex-watchers, it's interesting times!

Update 31 Jan Gordon Upton has posted a 'teaser' on RCMF

Sensor soup

2011-01-21T21:28:00.003Z

A tasty dinner

Telemetry with M-LINK, and some thoughts on the Spektrum DX8

2011-01-19T00:47:00.106Z

Today I had my first taste of Multiplex's telemetry system in action. I flew my Easy Glider electric with two sensors: the 35 Amp current sensor, and Altimeter/vario. Controlling this lot was a Multiplex Royal Pro 12 M-LINK transmitter and RX-7-DR M-LINK receiver.

So how did it go? As the there is a review pending in RCMW sadly my lips must remain sealed; suffice to say, I was smiling when I left the field.

While I was there a chap came along with a T-REX 600 equipped with a Spektrum DX8 and a temperature sensor. Now, Spektrum describe their telemetry system as 'integrated', but this is only half true. While the DX8 transmitter is telemetry-capable (you can view the telemetry data on the screen), the AR8000 receiver cannot do the downlink - you have to install an additional downlink module (TM1000) in the plane. Compared with the M-LINK telemetry, Spektrum's solution looks distinctly klunky.

Screen placement is important for telemetry. The DX8's screen is located near the bottom of the case, a drawback shared by most Asian sets as they compete to see who can provide the biggest screen. Unfortunately this is just about the worst location possible for displaying anything at all, let alone telemetry data. Neither was the screen particularly easy to read.

I'm sure that the DX8 is a fine system, but radios need to be designed with telemetry-friendly ergonomics if the benefits are to be truly realised.

Telemetry is an exciting development, with the potential for safer and more enjoyable flying. The challenge for the manufacturers is to work out cool ways of using it, of programming the sensors and of presenting the data to the user.

Telemetry a la Multiplex. Note the very clear screen. Easy Glider in the background, with 35A current sensor just visible. On the transmitter screen, line 3 shows instantaneous current (almost zero as the motor is switched off), line 4 is peak current from the previous flight, and line 5 is mAh remaining in the flight battery. The last line is highlighted because it triggered an alarm. A total of 15 data lines can be monitored simply by plugging in extra sensors.

Multiplex M-LINK telemetry - first thoughts

2011-01-03T19:12:00.041Z

Multiplex are making quite a splash these days. Their M-LINK 2.4 GHz spread spectrum system is bi-directional, and supports a neat system of fully integrated telemetry.

The DR and DR-PRO receivers have telemetry of receiver voltage and signal quality built-in. Telemetry data is displayed directly on the Royal Pro and Cockpit SX M-LINK transmitters (no external data viewer box is necessary). The telemetry-capable receivers can also link to external sensors for monitoring current, voltage, RPM (two types), temperature, and altitude/rate of climb.

I am currently testing out a telemetry capable M-LINK system for review in RCMW (March or April 2011 issue). First impressions are pretty positive, and I'm really looking forward to flight testing it. [As I write, the wind has dropped to around 10 mph, the sun is shining... it's time to go down to the field!]

All connected: RX-7-DR receiver and two external sensors. Even without any sensors, the Rx transmits Rx voltage and signal quality. To give you some idea of scale, the batteries are AAA size.

So you think you can trust the 'Cloud'?

2010-12-23T01:23:00.005Z

Sportube - a cool way to transport your planes

2010-08-15T15:58:00.010+01:00

The arrival of cheap air travel has opened up all kinds of opportunities, including the ability to fly in competitions abroad. However this carries its own risks - you don't want to arrive with your model resembling a Walkers crisp under a lorry.

The solution of course is to make a transportation box. However, the design brief is not an easy one, which is why several F3F flyers have chickended out and just bought Sportubes.

Sportubes are made of heavy duty plastic. They were originally designed for transporting skis and snowboards aboard aircraft, but they are ideal for our models as well. They consist of two long boxes, each open at one end. One slides into the other to create a long closed box. The length is adjustable and a locking pin stops the two halves from sliding apart.

My Sportube is a Series 3, the biggest in the range, and this is the one to get for F3X. It's black and looks the business. The handles are comfortable and of good quality. It's got a pair of wheels at one end, good for smooth surfaces (but probably not up to repeated use on rough ground). It comes with a shoulder strap. You can also get a hand-tow rope, useful for wheeling it around an airport concourse.

When fully collapsed, the box takes surprisingly little room in the workshop, yet when expanded it'll take two F3F models, and any spare space can be packed out with your clothes. For once, I'm actually looking forward to packing!

Addendum 20 Jan 2011: My sportube has passed its first test passed with flying colours, during its inaugural ferry trip to Lundy Island.

Quayside, Ilfracombe.

Pete Bailey (1947 - 2010)

2010-04-30T16:52:00.019+01:00

F3F pilots are a close knit bunch, thanks to the wonderful sites we are privileged to fly from, and the shared experience of competition. So it's always a keenly felt loss when we lose a pilot.

Pete Bailey is the latest to leave us, after succumbing to illness all too soon after his retirement. Pete was an interesting and compassionate man with firmly held views. He was also a determined competitor, and I always enjoyed his company at the many events we attended.

Jon Edison has prepared a simple but fitting tribute which you can read here

La Muela - the Slideshow

2010-04-15T18:38:00.136+01:00

It's just after Easter, and I'm slowly coming down to earth after another memorable two-week trip to La Muela in Spain. The full report is on my RC-Soar.com site, but for technical reasons it was not possible to embed a slideshow (at least not without breaking the page's XHTML). So here it is:

Click "Play".
To switch to full-screen, click the "Full Screen" icon at the bottom right.

My thanks to my companions for another great holiday, and to our Spanish friends and all at the Hotel Infante for their hospitality - ¡gracias a nuestros amigos, nos vemos el año proximo!

My new Pentax - old before its time?

2010-01-17T03:48:00.064Z

For a few years I've been using a simple 6 megapixel digital SLR - the Pentax K100D - for the RC-SOAR gallery. It's light, small and is fine for making prints up to A4.

However, camera technology has moved on, and so have my photographic needs. So after a bit of research on the photo forums, I have just bought a Pentax K-x body. It's the same size as than my old cam, but at a stroke my megapixel count is now doubled to twelve!

The K-x is a super little camera. And yet, even as I get to grips with it, I have the feeling that the days of this type of entry level dSLR camera are probably numbered.

The new kid on the block is the mirrorless interchangeable lens camera, exemplified by the Panasonic G1 and Olympus EP-1. These use more or less the same technology as cheaper point-and-shoot cameras, with one major enhancement: the lenses can be changed. So like with dSLR's you can choose the lens to suit the occasion. Unlike dSLR cameras however, there's no swinging mirror to shake the camera, no pentaprism to take up space, and the lenses are smaller too. Plus the design is better suited to the now almost ubiquitous video. And to cap it all they're cheaper to make and more reliable.

Drawbacks? These cameras do not employ optical viewfinders. However with the G1, Panasonic have shown that electronic viewfinders can be surprisingly good.

I'm sure we'll be seeing a lot more examples of mirrorless interchangable lens cameras in the future, and it's the consumer electronics companies like Samsung and Panasonic rather than the established camera manufacturers who will be leading the way.

Multiplex M-LINK 2.4 GHz review: progress report

2010-01-08T19:43:00.018Z

To those of you wondering when my review of the Royal Pro M-LINK will hit the stands: my editor at RCMW put it back by a couple of months as apparently there was a raft of new products in the queue (including at least one other 2.4 GHz system).

Well the good news is the queue has cleared and the final copy date is looming large, so I guess the M-LINK review will be in print by the summer. By which time, everyone will of course already have done their research on the Internet. C'est la vie!

Well thanks to the recent humungous snow falls in the UK, I doubt that flying has been on many people's mind recently. On the other hand, it's great weather for toboganning, which probably explains why so many recycling bin lids have gone missing round here.

Now if you thought that snow and London don't go together, here's the scene on Primrose Hill yesterday:

Multiplex M-LINK 2.4 GHz - upcoming review

2009-10-16T01:34:00.132+01:00

Today I did some initial flight testing of the Multiplex Royal Pro 12, equipped with a brand new M-LINK 2.4 GHz module - woo hoo!

So, what's new? Well M-LINK is the name for Multiplex's new spread spectrum system, and is their answer to Futaba's 'FASST', Spektrum's 'DSM-2' and Jeti. More than that, though, M-LINK is the only system to support fully integrated telemetry (the Jeti system has telemetry, but a separate receiving box is required to view the telemetry data).

With an M-LINK transmitter and a telemetry receiver, it's possible to monitor your model's vital functions right there, on the screen of your Royal Pro or Cockpit SX M-LINK transmitter. It's cool. I got to see a demo of the telemetry system - albeit on a ground based test rig - at the Multiplex Fly-in at Baldock, and it was impressive.

My review of the Royal Pro 12 with the M-LINK conversion will appear in RCMW. Suffice to say that initial flight tests with an Easy Glider went well, and further flight tests are planned. The receiver supplied for review is the RC-7-DR Light receiver, which is not telemetry capable. However I've been promised a telemetry capable rx for a subsequent review. And an M-LINK module for the Profi 3030/4000 is also on its way.

For more details of M-LINK, have a look at the Multiplex web site.

How I Swapped a Plane for a Camera

2009-09-12T14:04:00.099+01:00

A couple of months back, my F3F mate Phil Taylor invited me to join him at the O2 (Milleniumn Dome) for some soaring off the nearby Thames river wall. Wow! This sounded like fun, so I soon found myself on the Jubilee line heading down to North Greenwhich, with my trusty Longshot DLG swaddled in protective bubblewrap.

And yes, we did manage to soar over the Thames, thanks to the surprising amount of lift available from the 12-foot concrete bank. Armed with a bit of height, we were even able to hook on to some thermal activity off the roof of the David Beckham Football Academy. If you want to read more about our little adventure, poke your eyes at Phil's post on RC Groups.

However, aside from the flying, what really caught my attention were the fantastic views of Docklands. I decided then that I would return for some photography. So a few weeks later, I found myself back at North Greenwich tube station, but this time without a plane. Instead, I brought my Pentax K100D, 40mm 'pancake' lens and a tripod.

The photo above is the result. It's blended from five separate captures using Enfuse, which compressed the very wide tonal range (bright sun/dark shadows) into a single image. It's currently work in progress - I'll post the finished article to my Flickr site.

The EeePC proves itself in combat

2008-06-13T22:37:00.143+01:00

Guadalajara street, after a rain shower. Our hotel there provided free Wifi access.

If there were any doubts about the usefulness of my EeePC netbook, they certainly vanished during my recent trip to Spain (see Asturias Open F3F).

With its small size, built-in Wifi, and preloaded software, the EeePC 701 makes a great holiday PC. I used it to access local weather forecasts, check my email, call home, look at photos - and even play the odd game on the ferry from Portsmouth to Bilbao.

Of course, for email and web access you need an internet connection. Fortunately, and to my surprise, Spain is well endowed with WiFi hotspots. In fact, all of the three hotels we stayed at had WiFi, as well as many motorway service areas. And it was all free of charge.

There are a few considerations if you're taking the EeePC on holiday. For example, you may not wish to use the supplied Thunderbird email package, as - like Outlook and other similar packages - it stores your emails locally on the computer. This makes it an open book for snoopers if the EeePC is lost or stolen. Instead, I used Googlemail in the Firefox web browser.Googlemail is not restricted to Gmail addresses - it can access all your other POP accounts.

The EeePC also came in handy as an image viewer. There was a small problem though - the EeePC has only patchy support for Pentax RAW files and only 4GB of disk space. To get round this, I wrote a short script which converts the RAW images from the SD card and saves them as small JPEG's on the SSD drive. The resulting images look fine on the EeePC's viewer, and hundreds of images can be stored in this way without running out of space

The EeePC also comes with Skype preinstalled, so I was able to use it to ring home, much to the surprise of our hotel receptionist who wasn't used to people talking into their computers (the EeePC's built in mic and speaker are fine for this if you don't mind people listening in).

In short, the usefulness of the EeePC on this trip far exceeded expectations for a £220 device, and it's now a fixture in the backpack/overnight bag. I'm still looking for a nice nickname though - somehow 'Eeyore' doesn't have quite the right ring to it.

Rc-soar becomes a fashionista!

2008-02-15T02:30:00.077Z

Complete change of subject... a photograph of mine has appeared rather unexpectedly in the Fashion and Style section of the International Herald Tribune!

The photo (see screenshot at left) was from a series of publicity shots I did for a friend who is a dress designer. The photo was submitted along with a press release to the IHT, and somehow it ended up heading the report on London Fashion Week.

The equipment I used was the same as I take with me to the slope i.e. ordinary entry-level 6MP dSLR camera. I had no idea that the photo had been submitted to the newspaper, so it all came as a bit of a surprise!

FASST goes slow

2008-01-18T07:55:00.001Z

Futaba have at last acknowledged what many already knew - that a number of FASST systems have been released in the wild with identical GUID's, which has resulted in at least one crash in the UK. This issue affects the 6EX and 7C transmitters, as well as the TM-7 module.

For background on this issue, see my earlier report. For advisory bulletins, see

The bulletins are identical except Ripmax make no mention of the Futaba 7C (perhaps it's not on sale in the UK).

Curiously, both bulletins mention another issue which appears to be unrelated to the duplicate GUID problem. I quote: "if the transmitter and receiver have lost their binding which required them to be re-linked, we recommend returning them to the Ripmax Futaba Service Centre for analysis. This is not expected behaviour and should be investigated accordingly."

A break from RC - my new Asus EEE PC

2008-01-06T17:13:00.002Z

As a complete change, here is my new toy - an Asus EEE PC. This seems to have been a huge hit in the US over the Christmas period, and having had mine for just two days, it's not hard to see why.

There are two great things about it - firstly its ridiculously small size - it fits easily in a small corner of a small backpack, with lots of room for camera, groceries, transmitter etc. And secondly there are no moving parts (except for a processor fan which is not always on anyway).

The EEE PC has built-in Wifi, three USB ports, an SD card slot (great for reviewing photos), a small but perfectly formed keyboard, and a 6.9 inch screen. And a solid state disk, so no whirly bits to go wrong. It even comes with a stetchy neoprene case.

Yesterday I took it to my local Costa Coffee for a test run. Surprised myself at how easy it is to use a public Wifi network, and in a couple of minutes it was all up and running. I finished off the Futaba 12FG review, checked my email, surfed the Futaba site, and remoted into my work machine - with not a glitch or pause. I could swear a neighbouring iBook owner was casting envious glances in my direction...

The EEE PC runs under Xandros Linux, and has a fast and easy to use front end and takes only about 25 seconds to boot up. It comes with OpenOffice 2 preinstalled (this is largely compatible with MS Office). And all for a bargain £220. Here's the link.

2.4 GHz is totally secure. Or is it?

2008-01-04T22:54:00.001Z

There are be thousands of modellers who entrust their models to 2.4 GHz radios, in the belief that 2.4 GHz spread spectrum transmission is inherently more secure than narrowband FM. And ignoring issues of external interference, hotspots, trees, water etc. 2.4 GHz is indeed much more secure than 35 MHz, because two spread spectrum transmitters simply cannot interfere with each.

...or can they?

A guy in my club claims that at another club he's a member of, two 2.4 GHz transmitters interfered with each other, leading to a crash. On further examination, the two transmitters were able to control the same receiver. Both transmitters were the same brand and type.

Now the only way this could happen, is they if the affected transmitters all left the factory with the same GUID. Since generating and loading GUID's is ultimately a human-managed task, we have to consider that this scenario is not as unlikely as it may at first appear.

If correct, this would be a pretty serious matter. Unless the offending transmitters could be identified by their serial numbers, the only totally option left to the distributor would be a total recall of all such sets sold. Otherwise, the manufacturers claims of interference immunity could not be guaranteed, and the purchaser would almost certainly have recourse under the law for a replacement set anyway.

Watch this space.

Futaba 12FG

2007-11-14T14:15:00.001Z

I've just received a Futaba 12FG, on loan for a forthcoming review in RC Model World. [to see the full review, click here]

Also received were two BLS 352 servos. These have brushless motors and are very impressive units.

It's early days, but the 12FG looks very interesting (the lack of more emotive language is deliberate, simply because I have not had a chance to do more than play with it.)

The radio supports PPM, PCM 1024 and PCM G3, as well as 2.4 GHz via an optional alternative RF module. It also sports 8 flight modes, several built in mixers and 10 programmable mixers. A 5114 (PCM G3) receiver is included.

The on-board memory stores up to 30 models, but push a 1GB SD card into a slot, and a mind boggling 1800+ free models shows on the display.

All this is very clever, but what Joe Flyer wants to know is: Can it fly my glider/i-c plane/e-flyer/turbine? Does it required a PhD to program? And is the manual any good? It's no good having advanced features if they are largely inaccessible to the target audience. These are some of the issues I'll be exploring in the review.

Today, I successfully hooked it up to my pulse width monitor. The screenshot shows the PPM 12 output.

Multiplex 4000: End of an Era

2007-10-29T21:04:00.001Z

On Friday 28th October a message appeared on the Multiplex Yahoogroup that production of this landmark radio has finally come to an end, and the news was confirmed to me by Multiplex in Germany. A shortage of key componenents has led to this situation, and no doubt what remaining stocks are left will be held back for spares.

Even amongst users of rival R/C systems, the Multiplex mc4000 was acknowledged as the most programmable model RC system on the market right up to the present day. Like Concorde, it's unlikely that anything quite it will come along again, for some time at least. Owners of the 4000 - of which I am one - will be carefully nursing their systems, perhaps even scouring around for a backup.

The one scrap of positive news is that Multiplex will continue to support existing units for the forseeable future.

The Good, the Good and the Ugly

2007-10-21T11:50:00.003+01:00

During the last few months, I have been lucky enough to test three radios for Radio Control Model World - the Multiplex Cockpit SX, the Spektrum DX-7, and Futaba 6EX 2.4. Each quite different, but all significant in their own way.

The first of these, the Multiplex Cockpit SX, is Multiplex's latest baby. Packed with clever and useful touches, the SX offers quick and elegant programming, synthesiser, channel check, excellent ergonomics, and good support for 6-servo gliders. I'm a great fan of this radio, and personally use it for all my sailplane and e-heli needs (the only exceptions are my F3F sailplanes which still use my MPX 4000, and my i/c models which use an old Futaba FF7 - I don't mind if it gets oily!). The Cockpit SX also offers very good value for money.

It's not all sweetness though; Multiplex inexplicably allowed a significant number of sets to leave the factory gates with sticking aileron trims. Talk about shooting yourself in the foot - c'mon Multiplex!

Next up: the Spektrum DX-7. This is a fine quality system, as you might expect from a JR-manufactured unit. The DSM-2 radio link felt very solid - if my life depended on a radio, this is the one I'd buy. However, the JR-inherited programming interface is showing its age, and the need for two receivers makes it awkward to install in smaller models. Bear in mind though that I primarily fly gliders - those who fly sport-power models may find the DX-7 is the answer to their prayers.

After the DX-7, I high hopes for the Futaba EX6 2.4 GHz. With its one-box receiver, and a respected brand name behind it, it promised much. Sadly, the reality was a disappointment. The FASST radio link works fine, but the rest of the system simply doesn't cut the mustard for a 6-channel radio with a quality brand sticker. You can't adjust the stick tension, the so-called 'flap' function is operated by a 2-position switch, the stick neutrals were unacceptably sloppy on my unit, and amazingly, there is no 'subtrim' menu - servo centre adjustment can only be done using the trims. The one saving grace is the FASST receiver which is easier to install and operate than the Spektrum's dual-box solution. Oh, and the 6EX is cheap for a 2.4 GHz set. One has to hope that Futaba's mid-range systems will be of better quality, however.

Latency and all that

2007-07-21T10:53:00.001+01:00

Latency, or how quickly a servo responds to a control input, is the latest marketing buzzword in R/C. It all seems to have started with claims in the Spektrum ads, and now everyone wants to know how their radio performs. It does have real relevence too - the latency of my Multiplex 4000 is visibly worse than other systems I've owned, to the point that you can easy see the delay on the bench.

For more info, take a look at these interesting links:

TX/RX eCCPM Latency Test Results (Runryder)
TX/RX eCCPM Output Test Results (RunRyder)
Futaba PCM 1024 Latency (PDF)

Cool Tool for Club Management?

2007-06-28T10:00:00.000+01:00

At the ISA, we use various free services on the Internet to enhance our little R/C community - a website, a Yahoogroup, various bits of free software, and an on-line photo gallery. However, one area where the Internet revolution has escaped us is the management of the club's membership records.

As with most most clubs, we store membership data in a spreadsheet. However, it's only accessible to one person, when there are several who need to use it. For example, the membership secretary needs to add or update names and addresses, the Yahoogroup admin will want to update email addresses, and the newsletter editor will need to create mailing labels.

What's needed is an online database which doesn't need rocket science to set up. The good news is that these are now beginning to appear.

Zoho Creator is one I've looked at, as it's free. It's similar in principle to Microsoft Access, except that everything is stored on-line. All you need is a web browser, and the relevant permissions to view or update the data. There is no need to install any software on your computer, no worries about backups, no distinction between users of Macs, PC's or Linux.

Currently Zoho has limited features, and is still a little buggy. However when it matures, it could well become a really cool admin tool.

Graupner pins XPS to its 2.4 GHz mast

2007-06-21T10:13:00.001+01:00

Graupner have announced that they are distributing XPS 2.4 GHz modules and receivers, including Graupner-branded units for Graupner systems:

Given Graupner's association with JR, it's interesting that they have shunned DSM-2 (as used in JR 2.4 sets), in favour of an alternative.

Whither Multiplex?

2007-05-26T02:21:00.002+01:00

Multiplex are used to being at the cutting edge of technology, so it's disappointing that - at the time of writing - they have no 2.4 GHz systems planned for release (see RCMF thread).

With Futaba and Spektrum/JR mopping up the the 2.4G early adopters, Multiplex can only see their potential market diminish as the months pass. Multiplex's sister company Hitec is also late to market with a 2.4 GHz system.

Will Multiplex press on with their own 2.4GHz system? Will they buy in the necessary technology from another manufacturer? Or will they simply throw in the 2.4 GHz towel? Whatever the outcome, I hope they continue with the development of conventional PPM radios - replacements for the Evo and 4000 are long overdue.

Is Spread Spectrum good for you?

2007-02-19T23:43:00.002Z

The success of the Spektrum DX-7 has taken 2.4 GHz firmly into the mainstream of R/C modelling. Yet while 2.4 GHz systems offer enticing advantages, there are some subtle compatibility issues to trap the unwary purchaser.

As you might expect, the two major systems (DSM and FASST) are not compatible, i.e. you can't operate a DSM receiver with a FASST transmitter and vice versa.

In addition however, there are compatibility issues within brands; for example, the DSM-1 Spektrum DX-6 does not support the latest DSM-2 AR6100 parkfly receivers. And Spektrum are not alone - Futaba's R606FS FASST receivers will only work with dedicated FASST transmitters. They will not work with FASST RF modules, as shown in this compatibility table.

Apart from being confusing for anyone contemplating a purchase, it begs the question: will the 2.4 GHz receiver you purchase today work with the transmitter you buy tomorrow? So here are some questions you may like to ask if you're thinking of dipping a toe in 2.4 GHz waters:

How long will the manufacturer support the protocol supplied with your system?
Is the protocol shared with other brands? (safety in numbers)
Is the firmware on your transmitter and/or receiver(s) upgradable to work with future protocols?

Contrast this with PPM systems, where any brand of transmitter made in the last 20 years will work with almost any brand of receiver made during the same period. Somehow, good old PPM is beginning to look rather appealing!

English Open F3F

2006-08-13T21:15:00.000+01:00

One of the great things about F3F racing are the fantastic landscapes on offer. Both images below were taken close to Whitesheet Hill during the 2006 English Open F3F.