Multiplex Funcopter
The Multiplex Funcopter is a fixed pitch helicopter designed to be the first or second step into the world of model helicopters. It is made of Elapor and the blades are quite flexible. It is based on the LMH Corona, which is no longer available but was very popular.
Unlike a coaxial helicopter it will not hover indefinitely without pilot input. In this regard it flies like a 'real' helicopter. This allows it to fly at speed and be relatively unaffected by gusts of wind. It's extra size and weight over many 'beginner' helis makes it more suited to outdoor flying.
However it's big advantage (for beginners) over most other helicopters is that it's designed for toughness, not aerobatics. The head speed is fairly low, the blades are bendy plastic and the head design is simple, robust and not overly rigid.
Many people have reported stripping the tail rotor gears when the tail touches the ground, and it appears that these are not as tough as the old Corona gears. Modifications have included a longer tail fin (to prevent it touching) and a belt drive conversion.
Contents |
Specifications
| Fuselage length | 855 mm |
| Rotor diameter | approx. 770 mm |
| All-up weight | approx. 1250 g |
| Channels | 4: yaw, pitch-axis, roll and throttle |
Equipment
Metal geared servos are recommended, as plastic servo gears can be stripped in a crash.
Alternatives to the Multiplex servos are the
- HiTec HS82MG
- D-MG16 Metal Gear 2.9kg/.08sec/18.8g
- HobbyKing HK-922MG Digital Metal Gear Servo 1.8kg/ 12g/ 0.07sec are a little too short.
Digial servos are not necessary, even on the tail, for basic flight. However advanced pilots do notice an improvement with a digital tail servo, such as the Inolab HGD digital 261HB Carbon Gear Servo 20g / .06sec / 2.4kg. TomC says it "works better than the hitec digital 5084".
Recommended good value gyros are the Hobby King 401B AVCS Digital Head Lock Gyro or the newer (and possibly even better) HobbyKing GA-250 MINI-MEMS Gyro. This one is fairly new but early reports are that it is better than the Futaba 401 (the usual 'gold standard' for mini heli gyros, and 10 times the price).
Recommended ESCs:
- HobbyKing 40A BlueSeries Brushless Speed Controller
- Mystery 40A Brushless Speed Controller (Blue Series)
Complete settings for this ESC
- Brake = off (supposedly the default but not always)
- Battery type = lipo (default)
- low voltage cuttoff threshold = high
- timing settings = auto (default)
- soft acceleration start up = very soft
- govenor mode = rpm off (default)
- switching frequency = 16kHz
- low voltage cutoff type = reduce power (default)
If you don't change either the timing or the switching frequency (or both), the motor does not always start cleanly.
Motor
The Funcopter is unique in being sold with a direct drive brushless motor (Himax C 6310-0225). The main reason for this is because it's common for other helicopters to strip teeth from the main gear in a crash. It also reduces the noise and simplifies construction.
Batteries
Average power draw is about 12-15amps. ~150 watts for the 3s setup and ~200 watts for the 4S. The FC is probably the most efficient heli on the market. At ~1.35kg, or ~3 lb, the power/weight ratio on 3s is only 150/3 = 50 watts/lb. Most hard 3D heli guys today are using +300 watts/lb. (See Sizing Power Systems)
The battery bay is 25mm wide, but you need to leave 1mm either side of the battery for the velcro strap, so batteries should be no more than 23mm wide.
- 3s batteries in the range 2650-3300mAh, rated to at least 20c. 2200mAh is about as small and light as you can go, which gives about 10 minute flights. 30c 3s 3300mAh packs fit easily and give 15 minute flights and the extra weight stabilises the helicopter. This heli can lift 3s4000mAh batteries, but while they give 30 minute flights, they are getting pretty heavy for a 3s setup and make it feel very sluggish.
Example 3s batteries 30c 2650mAh 30c 3300mAh
- 4s 2650mAh batteries give more speed and power, for experienced pilots. 30c or even 40c packs do give a noticeable performance improvement. (2200 mAh batteries would in theory give enough power, but are usually fatter and wouldn't fit in the battery tray). You can expect 13-15 minute flights with these batteries.
Example 4s batteries: 20c 30c 40c
Blade Grips
The blade grips have 5 dots on them, indicating that they are set for 5 degrees of pitch. 3°, 4°, 5° and 6° grips are available (and you can run two different pitch grips, to give an effective pitch half way between the two) Using lower pitch grips requires the head to turn fast to generate the same amount of lift. The extra head speed increases cyclic control and reduce pitch-up at speed, but maximum lift is reduced (unless you use a higher voltage battery) and you could exceed the maximum recommended headspeed (2000rpm)
If you have the lower degree grips, you have to keep in mind the lower climb rates especially when coming in for a landing!!!!
Mods
Many of the old Corona mods can be used on the funcopter, although some parts have changed from imperial sizes to metric.
- Belt driven tail.
- Carbon fiber, zero pitch flybar.
- CNC rotor head.
- 500 class tail pitch slider.
There are many more (aftermarket and DIY) at funcoptermods
