Multiplex Cockpit MM Review
Here's my comprehensive review of the Cockpit, the lightweight computer radio from Multiplex.
These specs are taken from the MPX documentation
- 7 channel PPM computer transmitter
- Digital trims
- Universal and Heli model types.
- Dimensions: 180 x 180 x 35 mm
- Weight incl. battery: approx 600 g
- Power supply: 7.2 V / 1500 mAh NiMH
- Current Consumption: approx 170 mA
- Operating temperature: -15C to +50C
Apart from the clean and stylish look, the first thing you notice is that it is very comfortable to hold - it's slim and nicely sculpted for the hand. The case is made of plastic. The front section has a sprayed-on silver finish.
Stick units are all-plastic. The spring tension and length are adjustable.
The unit has digital trims. The advantage of digital trims is that the settings are retained for each model, and cannot be accidentally changed when the Tx is switched off. Each increment is acompanied by a beep, with centre position distinguished by a different tone. The trim position is shown on the LCD. There is no auto-repeat.
On my unit the sticks were not as smooth as on comparable Japanese kit. In particular, there was excessive friction present on both stick units.
[Sept 2002. The stick friction is just too irritating - decided to investigate! Unscrewed the sticks using a miniature Torx screwdriver. Unplugged wiring from the main board and removed complete stick units from the case.
The main cause of friction was the gimbal bearings - the plastic yokes were slightly warped during moulding. I relieved some of the tightness by carefully scraping off plastic from the mating surfaces on the yolks. This improved the feel considerably. Multiplex need to tighten their QC in this area.]
A slim stainless steel antenna screws though a hole in the top of the case. When not in use it can be stowed into a recess at the back of the case.
The Cockpit can drive 7 servo channels using the controls as shown below. In addition there are some special function switches.
Controls and Special Functions
|Dual-axis stick units|
|Slider (E)||Between sticks|
|Rotary knob (F)||Above LH stick|
|3-position switch (G)||Top right|
|Combi switch||Top left|
|Dual Rate||Second from left|
|Timer switch||Second from right|
|3-D Adjuster||Above RH stick|
The back of the case comes off by sliding two fasteners near the top of the case.
Construction is neat and tidy. Each control has a wiring harness which plugs into the main board. Does this mean you can swap plugs around as on the 3030 and 4000? You're not supposed to do this on the four primary channels, in any case the same effect is done in software via Tx mode selection.
However, you can plug any suitable switch or knob into channels 5 and above. There is a facility to calibrate the control centres and end-points on these channels to allow for manufacturing tolerances.
My unit had a 6-cell 600 mAh battery. The latest units have 1500 mAh NiMH cells included. All AA size. The pack is held in place by end brackets which can work loose - a dollop of Evostik would hold them in place.
Nine model memories are provided which is pretty generous at this level. Full marks here. A sticker is provided to write the names of the models corresponding to each memory number. As one might expect on a budget set, you cannot switch model memories in flight.
The functions of the main sticks and slider are determined by the stick mode.
Forget "mode 1" and "mode 2" - there is a choice of 8 stick modes! The mode is selected in a screen, and can be different on each model. The mode may be changed for example if you want to hand the sticks to a pilot who is used to a different mode.
|Mode||LH Stick Controls||RH Stick Controls||Slider|
My unit has the latest v2 firmware. The instruction manual is a 45-page A5 leaflet, with a multi-lingual addendum for v2. Incidentally Multiplex are to be commended on displaying the firmware version in an info screen.
Programming is performed using a 3D adjuster knob which can be twisted and clicked. The 3D-adjuster manages to do the same things as all those buttons on Far Eastern sets. Twist to select from a list of items. Click to confirm a selection and move to a submenu. You soon get used to twisting and clicking, and it all works very well.
For some settings you also use the sticks themselves to select the direction to be adjusted. Clever!
Model Types and Mixers
Two model types are supported - H (helicopter) and U (Universal). I won't deal with the former here. The Universal type provides a quite comprehensive set of mixers:
- Combi (coupled ailerons and rudder)
- Diff (2 wing servos)
- Spoileron (both ailerons up)
- Throttle-elevator compensation
- Flap-elevator compensation
- Spoiler-elevator compensation
There is no snapflap, and no "free" mixers.
The LCD is small at 7 x 2 characters + trim graphics, so abbreviations are used. The manual explains the abbreviations and it's all logical. e.g. SPL means spoiler and CO means compensation, so SPL-CO is compensation for spoiler, and SPLRN is spoileron.
Here are some examples of the programming screens.
This is the screen at switch on. Model type = UNIversal, Model #2, battery voltage = 7.6V. Note the right hand stick has off-centre trims on both axes.
Servo setup screen for Servo 4 - adjusts centre and travel.
The Aileron, Elevator and Rudder controls each have individual dual rate adjustment. A single D/R switch handles all three controls at once. D/R is mixer-aware, so for example if two servos are used for aileron control, adjusting the D/R value for Aileron will affect the travel of both servos.
100% and 60% dual rates are set up for the main controls by default. You can't disable the D/R switch, but the same effect is achieved by setting the travel to be the same for both positions of the switch.
Exponential can be set for Aileron, Elevator and Rudder controls.
Channel assignments depend on the model type and mixers:
|Chan||Default||w. DIFF||w. V-TAIL||w. DELTA||Servo|
|3||Rudder||V-tail.2||Tail rot. (yaw)|
|6||Control (F)||Control (E)|
|7||Control (G)||Control (F)|
Any channel 1-6 can be electronically duplicated to channel 7 using the Electronic Y-lead feature.
Multiplex servos use a centre pulse duration of 1.6ms instead of the more usual 1.5 mS. No worries, for each channel there is an option to select either 1.6 or 1.5 centres, so you can mix mpx and non-mpx servos in the same model.
Timers and Alarm
Two timers and an alarm are provided. The "normal" timer is easily accessible for ad-hoc timing. Alternatively it can be linked to the throttle stick for timing motor runs on electric models.
|Op Timer||Measures elapsed time since last reset.||Via menus|
|Normal timer||Triggered by timer switch or throttle (user selectable)||Press 3D Adjuster|
|Countdown timer/Alarm||As above. 15 sec increments, countdown beeps for last 10 seconds.||Press 3D Adjuster|
The unit has a number of clever features which caught my eye.
First, how not to do it: on the Graupner/JR mc12 which I reviewed in RCMW, if you set up a V-tail mix, you have a 50% chance of connecting the V-tail servos the wrong way round, in which case you have to reverse the servo connections at the receiver. The Cockpit allows you to do the reversing in software.
Servo Travel is Servo Limit
At last - a budget set where Servo Travel is also a true "never exceed" setting. It means that you can set individual mixer inputs at their maximum, at the same time setting a limit on the movement of each servo to protect the hinges.
By contrast, on your average FutJR you'd have to split the available safe movement between rudder and elevator 50/50 or 60/40, thus compromising the amount of control authority on each. Unless you buy a top of the range Futaba 9ZAP...
Aileron Differential Suppression
This is a really cool feature straight out of the 3030. As you deploy spoilerons (both ailerons up) any aileron differential you may have set is gradually suppressed. Full movement is restored to the downgoing aileron, allowing maximum roll response. Together with the Servo Travel function, it takes all the hassle out of setting up aileron brakes in models like the Mini Ellipse and makes it easier to fly with brakes deployed. In addition, any elevator trim changes can be mixed out using the SPL-CO screen. Excellent.
The Channel Check module (left) can be purchased as an optional extra. It plugs into the main board of the transmitter, and requires a matching receiver crystal.
Channel Check prevents the transmitter radiating when you switch on, if it detects another transmitter radiating on the same frequency. It will not help if somebody switches on while you are flying (unless they happen to have a similar module).
The need to change an extra crystal makes it a bit of a hassle but if you only fly on a single frequency then it's an excellent safety feature.
I spent about an hour familiarising myself by looking at the manual and experimenting, after which setting up was quite straightforward.
I set up model #1 for a Mini Ellipse equipped with Pico 4/5 receiver. I used V-tail, Spoilerons (both ailerons up for landing), Spoileron/Elevator Compensation, Differential and Flapperon. I also use a little Expo on the elevator. The lack of snapflap (elevator to flapperon) mixing was a slight niggle, but overall this set up works well.
I also programmed it for my Zagi on model #2 using the Delta mixer. If you're happy with equal up/down movement on the elevator it's easy, otherwise is quite tricky to get the exact movements required for both elevator and aileron - you have to juggle servo travel, dual rate and aileron diff. This is because the Rate adjustments, which are meant for on-the-field adjustment, do not allow differing amounts of travel either side of centre.
The Piccolo e-heli was set up on #3.
For the Piccolo I removed the ratchet on the throttle stick to provide finer control over rotor speed. Actual flying was comfortable, although the lack of "auto-repeat" on the digital trims made it awkward to trim in flight.
It was a better story with the Mini Ellipse and Zagi. The transmitter is soooo light! I didn't even need a neck strap. I found making programming adjustments on the field was easy, there was no need at all for the instruction manual. As to the actual flying... the Tx radiated when switched on, and the models went in the air and came down in one piece.
Let's first consider the alternatives from Multiplex. Should you buy a Cockpit or a 3030? Should you hold off for an Evo?
- The Cockpit does not have any mixes for four wing servos so think twice about using the Cockpit with a glider with separate flaps and ailerons. You could double up the flap servos using the Y-lead function, but a 3030, 4000 or Royal Evo would be a better choice for this kind of application.
- The 3030 will do everything the Cockpit will do and a whole lot more, but it's heavy to cart around and the ergonomics may not suit everyone. It's built like a tank though.
- The new Evo is more capable than the Cockpit and is also light in weight, but will cost more (when available).
As for Far Eastern sets in this price range, the Graupner/JR mc12 which I reviewed in RCMW was less capable and more difficult to program. The Futaba 6 has no dedicated sailplane functions. The Hitec Eclipse 7 has a long feature list and may be worth investigating if you can put up with the bunny rabbit styling, but I haven't tried it myself. I have no info on comparable JR's.
The design of the Cockpit is a breath of fresh air compared with the usual Far Eastern clones. It is ideal for sport gliders with two wing servos, like the Mini Ellipse, and HLG's. DLG flyers will want to look at special mods (see links below).
The main drawback was the sticks, which had excessive friction on my unit.
All in all though, it's definitely worth considering as an entry-level computer system.
- Light weight.
- Easy programming
- Excellent support for aileron brakes.
- Looks great.
- Sticks needed freeing up on my unit.
Modifications for DLG http://www.monkeytumble.com/hlg/cockpit.htm