The Silverlit PicooZ
A tiny, low cost, easy to fly helicopter, suitable for the office or living room, the Silverlit PicooZ was one of the big gadget hits of 2007. It has sparked a number of imitations, but still remains the iconic image for micro sized helicopters.
As is typical throughout the Silverlit range, the box contains everything you need to get flying. There is the PicooZ helicopter, a combined two channel controller and charging station, a spare tail rotor, some sticky aluminium pads for flight trimming and the instruction manual. All you have to supply are six AA batteries and a small cross head screwdriver to fit them.
Configuration
The PicooZ is conventionally arranged with a twin blade 132mm diameter main rotor and 30mm tail rotor. The all-up weight is 11 grammes. The EPP foam fuselage houses the battery, electronics and the motor that drives the main rotor through a large gearwheel. The gearwheel is visible, but protected by clear mouldings. A plastic tail boom protrudes from the rear of the fuselage supporting the tail motor. From the side of the fuselage protrudes two stub wings that act as landing gear. On the starboard side the recessed on/off switch and charging socket.
Above the main rotor there is a small weighted propeller the fulfills the role of stabilizer (or fly) bar. It connects to the main rotor using small struts such that rocking of the stabilizer changes the main rotors pitch. By acting as a gyroscope the spinning weights keep the helicopter flying level.
Controller
The infra-red controller doubles as the charging station for the PicooZ. A hatch on the controller slides down to reveal an umbilical cable that plugs into a socket on the PicooZ’s fuselage. With the power switch on, the charge LED will illuminate until the battery is full.
The controller has two levers: the left stick operates as a throttle for the main rotor to control climb and descent; the right stick operates the tail rotor to control direction. Both are spring loaded to neutral. Below the tail rotor control are two trim buttons. These are used to keep the fuselage pointing in one direction with the tail rotor control set neutral. They are set my multiple presses and will have to be adjusted each time the main rotor speed changes.
The final switch on the controller is the channel selector. This should match the channel printed on the underside of the PicooZ’s fuselage. In this case channel C.
Airspace
The PicooZ’s manual recommends a room about 3m x 5m x 2.5m. Personally, I would say that, once past the beginner stage, any CLEAR space where you can stay more than 2m away is OK. So bedrooms, lounge, office or cubicles are all possibilities. I’m sure this has been part of the PicooZ’s appeal. The manual doesn’t quote a maximum range for the transmitter, although the Amazon product page quotes 10m. One thing to avoid is a room with strong air currents. My normal flying space as some high top opening windows for ventilation. It they are open the PicooZ can be sucked towards them from a couple of metres away. The only way to stop it being sucked outside is to cut the throttle and plummet earthwards. The strong sunlight through the windows can also cause the PicooZ to fall out of the air as the sun’s infra-red overpowers that from the controller.
Flying
All charged up and switched on the PicooZ was placed on the floor for the first flight. Having never flown a helicopter before and not wishing to risk damaging it, the main rotor was throttled up slowly. As lift overcame gravity the PicooZ started to skate around the floor until powered down to avoid the rotor hitting a desk.
For the next attempt more throttle was added to get it flying out of ground effect. It rose quickly pirouetting around its axis. To avoid the ceiling the throttle was reduced causing the PicooZ to plummet. After a couple more attempts and able to hold a reasonably constant altitude it was time to stop it spinning. The right trim button was pressed repeatedly until a constant heading was achieved.
Here the limitation of the two channel control becomes apparent. You can go up and down and turn left right, but how do you make it go forwards? Here you have two options.
- Single rotor helicopter dynamics are such that the PicooZ will move slowly forward during a gentle clockwise turn. Reversing the turn will cause it to stop. By repeating this technique the PicooZ can be made to fly in circles. However, its slow going and you soon get fed up.
- The second method uses the self-adhesive aluminium pads supplied in the box. Fixing them under the nose of the PicooZ shifts the centre of gravity forward. The resulting tilt of the main rotor means that some of it’s lift acts to push the helicopter forward. You need all three pads to see the benefit. The problem with this technique is that you loose the ability to hover whilst keeping a constant heading. To stay over one spot you have to keep it turning in small circles. I would still recommend this solution though.
Towards the end of a flight you will find yourself adding more and more throttle to maintain height. Before the power is totally exhausted bring it in for a safe landing. Before recharging the PicooZ give the battery 10-15 minutes to cool down first. This will extend it’s life significantly.
Unlike the Palm-Z, there are no surprises in the PicooZ’s flight envelope. It’s behaviour is predictable, although fine control takes practice. Without a gyroscope connected to the tail rotor every speed change of main rotor causes the PicooZ to yaw. With experience you learn to compensate for this with the tail rotor control.
After only a couple of flights I found myself attempting spot landings and flying between the cables holding up the suspended lighting. Sometimes I would clip a cable, causing the PicooZ to fall to earth and each time no damage was sustained. As yet I have not needed the spare tail rotor.
Another challenge is to fly really close to the ground: less than 100mm (4 inches). On carpet especially the ground effect causes a strong yaw, the severity of which varies sharply with small changes of height. Flying in straight line requires a lot of concentration. Ground effect also adds to the fun flying over a table. Flying onto the table causes a sharp yaw and slight climb and then as ground effect is lost flying off the other side it can drop out of sight. These challenges and more serve to extend the interest span of the PicooZ.
Conclusion
The PicooZ has become one of the most desired ”big boys toys” and for good reason. It provides a lot of fun in a small package without needing a large operating space. There is extra satisfaction in that the fun happens in the real world instead of on the virtual 2d world of a computer monitor.
I have now flown a couple of other 2 channel electric helicopters, but for now the PicooZ remains the favourite with it’s predictable and reliable operation. Each of the others have had some failing that spoils the experience. More of that in future reviews.
Following the PicooZ’s success the range has been extended with versions featuring Huey and Apache gunship style fuselages, insectoid fuselages and for the competitive the Sky Challenger twin pack. With this set you get two helicopters and controllers on different channels that can be flown together. Each helicopter has an infra-red emitter that if aimed correctly, will cause the opponents helicopter to cut out and fall to earth. The spare tail rotors may come in handy.
Facts and Figures
Whats in the box
- PicooZ helicopter
- Combined infra-red transmitter and charging station
- Multi-language manual
- Trimming pads
- Spare tail rotor
You have to supply
- 4 x AA batteries
- Cross-head screwdriver in order to fit them.
Dimensions
- Main rotor diameter: 132 mm
- Fuselage length: 170 mm
- Height: 70 mm
- Weight: 11 grammes
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