Review of electric flight

The Silverlit MX-1

March 30th, 2009 captain

mx-1
The MX-1 re-establishes Silverlit’s position as the producer of the world’s smallest remote controlled helicopter.  It’s small size enables it to be transported inside the combined controller/charger, creating a portable package that can be left in your bag, allowing for a quick flight when an opportunity arises.

The downside to this miniaturisation, is that the MX-1 is difficult to fly smoothly.  It’s probably the least controllable helicopter that Silverlit produces.

Configuration

The MX-1 features the standard main and tail rotor arrangement shared by all the other helicopters we have reviewed so far.  The on/off switch is on the starboard side and the charge connector is on the underside between the skids.

As the photos below show, the MX-1 is about 65% the size of the PicooZ.

Side by Side View of PicooZ and MX-1

Side View of PicooZ and MX-1

Top View of PicooZ and MX-1

Controller

To make the controller more transportable it uses sliders rather than sticks.  This makes it reminiscent of the Palm-Z’s.

MX-1 Controller

Behind a sliding panel is a storage compartment for the MX-1.  This compartment contains the charging cable and with the charging socket on the underside of the MX-1, it allows the helicopter to be charged whilst in storage.

MX-1 Stored In Controller

I have been carrying the unit around in my laptop bag now for 9 months now and it has held up really well.  The only damage it has received is that some of the silver paint has worn of the corners.

MX-1 Controller Wear

Airspace

The manual recommends a room of about 3m x 5m x 2.5m, free from drafts, bright lights and strong sunshine.

Flying

When it comes to smooth flying the small size of the MX-1 works against you.  Small adjustments to the controls have big effects, making it impossible to hover or maintain direction.  The challenge of the MX-1 is not steering it around a course, but just keeping it within your flying space.

In the end I was most successful flying the MX-1 by trimming the tail rotor as best I could at an approximate hover and then controlling the direction of turn by climbing and descending.  The addition of some Blue-Tak to the nose gave me some forward speed making it easier to stay away from the walls.

Another problem I found with my MX-1 was that it would suddenly drop out of the air.  I thought this would probably stop once the battery had been cycled a few times, but it never really went away.  In one case the tail rotor got tangled with some fibres, which ultimately caused me to replace the tail motor.

Modding the controller

In help maintain a constant hover I removed the spring from the main rotor slider on the controller. To do this I removed the four screws from the back of the controller and the fifth one from inside the battery compartment.

MX-1 Controller Screw 5

The two halves can then separated.  Make sure you don’t lose the small pieces of felt that cover the switches.

The main rotor has  spring to shut down the rotor when the slider is released.  You can see it on the right had side below.

MX-1 Controller Facia

After slackening the screw, I unclipped the spring from the slider, rotated it round a bit and re-tightened the screw to hold it still.

MX-1 Controller Modded Spring

Finally the controller was re-assembled and screwed back together.  As with this mod on the other controllers, before turning the controller on, check that the main rotor control is pulled right back.

Conclusion

The MX-1 only has one feature that I can recommend it on and that is it’s portability.  If you are looking for a second or third helicopter that can live in your bag to fill the odd spare moment then the MX-1 is for you.  But you definitely shouldn’t buy this as your first micro helicopter.  For that I would still recommend the PicooZ.

Facts and Figures

Whats in the box

  • MX-1 helicopter
  • Combined infra-red transmitter, storage and charging unit
  • Multi-language manual
  • Spare tail rotor

You have to supply

  • 4 x AA batteries
  • Cross-head screwdriver in order to fit them.

Dimensions

  • Main rotor diameter: 96 mm
  • Fuselage length: 115 mm
  • Height: 60 mm
  • Weight: 8 grammes

Manufacturers Website

  • Silverlit main site
  • MX-1 product page – (Link removed due to malware infection of product web page)

Available in the UK From

The Silverlit Atlas

November 14th, 2008 captain

The Silverlit Atlas
The Silverlit Atlas is the natural progression from the PicooZ. Extra buttons on the transmitter add forward motion control to the existing up/down and rotate left/right options. The box describes this as 3-channel control, but with no backwards option, it’s more like 2½.
The Atlas is also available as the Uranus which has led to much sniggering and many school boy jokes on various forums. The only difference between the Atlas and Uranus is a minor variation in the fuselage profile. For the rest of this article I will only refer to the Atlas.

Configuration

The size and configuration is very similar to the PicooZ. The fuselage is significantly narrower and the large gear wheel is absent. A two stage gearing is used instead which is compact enough to remain wholly within the fuselage.
Front view of PicooZ and Atlas
Plan view of PicooZ and Atlas
The main selling point for the Atlas is the forward motion control. The mechanism to achieve this is connected below the main rotor. Two arms project down from the rotor to a circular ring surrounding the rotor shaft. Above the rotor is Silverlit’s now familiar propellor style stabilizer bar.
Atlas Rotorhead
A copper coil sits in front of the rotor shaft. A current applied to the coil displaces the suspended ring, which combined with the action of the stabilizer, changes the flight geometry to generate the desired forward thrust.
The coil
The power switch and charging socket are on the starboard side of the fuselage.

Controller

The controller only differs from the PicooZ in two aspects: one functional and one cosmetic.
Functionally there are two buttons on the back that control forward flight. They are located where your index fingers naturally fall. Pressing the left button causes a small forward movement, the right a larger movement. For continuous forward flight press and hold them together.
Cosmetically, the controller has had a face-lift. It now has a 1950′s sci-fi feel with it’s triangular LED bulb and metallic silver panels.
Front of Atlas controller
Rear of atlas controller
As with all the other micro-helicopters smaller than the Gyrotor the flight battery on the Atlas is charged from the controller via an umbilical cord.
Charging the Atlas

Airspace

Standard to this size of helicopter, the manual recommends a room of about 3m x 5m x 2.5m, free from drafts, bright lights and strong sunshine.

Flying

My first impression of the Atlas was that it did not handle as well as the PicooZ to the point that I got the PicooZ out to check.  I’d been flying the Palm-Z a lot and wondered if my helicopter skills were rusty.  The problem was definitely with the Atlas.  It wasn’t that it was uncontrollable, just that it lacked precision.  Where as I could land the PicooZ on coffee mat and fly it under a chair, the Atlas needed a dustbin lid and a table.  I put this down to the extra mobility of the rotor head.

Halfway through the first flight I decided to test the forward flight controls.  I pressing the left button for a short forward movement.  There was a delay and then the Atlas tipped forward for a second, moved about 15cm (6 inches) and then swung backwards and forwards like a pendulum.

Pressing the right button was similar, just with a longer forward movement: about 40 cm.  At the end of the movement it started descending sharply, dropping to the floor.  Adding power to the main rotor had no effect.  Following an immediate takeoff it was back in the air as normal.

For the final test both buttons were pressed together for continuous forward flight.  The Atlas started speeding around in large circles.  Control whilst holding the buttons down was difficult especially combined with the speed.  After a short sprint the Atlas again dropped to the floor.

During the next eight to ten flights this dropping behavior diminished to nothing as the Li-Poly battery became conditioned.  This behavior is typical and is seen in all of the micro helicopters as coarse speed changes during early flights.  The effect was more pronounced on the Atlas due to the extra current draw of the rotor pitching coil.  I had a four month period where I didn’t fly the Atlas and found that the dropping behavior had partly returned.

On some flights the motors unexpectedly cut out during the flight with a fall to earth.  Once recovered and relaunched, flying continued as normal.  According to the forums, the Atlas has a thermal cut-out to prevent damage to the electronics.

As direction control during forward flight was minimal, I followed the PicooZ’s example and added a little weight to the nose using Blue-Tak.  This gave a slow but constant forward motion, to which the (semi)controllable forward flight could be added as wanted.

Modding

The only mod I have made to the Atlas setup is to remove the spring from the main rotor control.  This was so I could explore the forward flight controls with the main rotor set for hover.  Although only a minor change, it proved useful enough that I kept it.

To remove the main rotor spring remove the four screws from the back and gently separate the two halves.  Make sure you keep all the buttons and switch covers that fall out.

Pulling the main rotor stick from its seating reveals an offset spring.

Removing the screw securing the spring allows it to be rotated out of the way.

After replacing the screw the sticks can be reseated before re-assembling the controller, ensuring all the small parts are replaced.

Conclusion

I find the Atlas difficult to recommend.  It may look better, but the “third” channel, does not live up to it’s promise and the lack of precision compared to the PicooZ leaves you feeling unsatisfied.

If your flying space is limited and you want to progress beyond the PicooZ then you might consider the Atlas, however I would suggest spending a little extra and skipping to Silverlit’s newer TandemZ-1 twin rotor (to be reviewed soon).

Facts and Figures

What’s in the box

  • Atlas helicopter
  • Combined infra-red transmitter and charging station
  • Multi-language manual
  • Spare tail rotor

You have to supply

  • 6 x AA batteries
  • Cross-head screwdriver in order to fit them.

Dimensions

  • Main rotor diameter: 132 mm
  • Fuselage length: 170 mm
  • Height: 63 mm
  • Weight: 12 grammes

Manufacturers Website

Available in the UK From