Sirius35
Posts: 8
Joined: 1/5/2004
From: n,
FL, USA
Status: offline
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Here are some notes about what I know or think I know after about a month of trying to fly the Smartech Aerohawk micro RC helicopter as a total newbie. From my experience it is unlikely many people will be able to fly the Aerohawk very well “right out of the box”.
The Smartech Aerohawk by Perfect Toys International is similar to the Ikarus Fun Piccolo or the FEDA Dragonfly and is the new version of the Skylark. The Cupid helicopter seems to be very similar to the Aerohawk.
The helicopter has a main motor, separate tail motor, two servos with no nameplates, a 750 mAhr 8.4 volt NiMH battery and an integrated electronics module. The four-channel FM receiver is a small 25mm PC board attached to the gyro/mixer and motor controller board. There is no separate gyro and there is no case on either the mixer board or the receiver thus saving weight. The design of the rotor head is different from the Piccolo or Dragonfly. The Aerohawk instruction manual is in English so broken you need a broken English to English dictionary (e.g. landing skid is “sliding pry”). The dragonfly has better, mostly applicable, manuals that you can download:
FEDA Dragonfly manual with details of cyclic mechanism: http://www.tedani.com/dragonfly.html
Another Dragonfly manual with better flight training procedures: http://www.rcmart.com/catalog/manual/dragonfly_manual.pdf
The gyro, mixer, and motor controller electronics board on the Aerohawk appears to be a "Chinese copy" of the Ikarus Piccolo piccoboard. Mine reads PTI V 1.33 and has a piezoelectric gyro 03JA by Murata. PTI is Perfect Toys International of Hong Kong.
has a long description regarding setting up the mixer and gyro on the Piccolo that is applicable to Aerohawk.
Looking at the left side of the helicopter, there are two screwdriver adjustments. They can be turned about 270 degrees from stop to stop. They are not hard to turn - don't break them by trying to turn beyond the stops.
The left control, marked 204, is the gyro gain and the right, marked 103, is the tail rotor mixer gain. Both increase clockwise. The mixer gain is very sensitive. Mine was set to about 80%, which was about right. Adjust more CW if heli tends to yaw left as main motor power is increased. The gyro adjustment was set at 100% and doesn’t seem to be very sensitive.
When you power up, the electronics sets the "zero" for rudder (tail motor) at whatever it is getting from the transmitter during the http://www.pgoelz.com/calibration interval so the transmitter rudder trim has no effect unless you move it after the electronics sets the zero (after the LED turns on). If you want to trim left you could set transmitter trim all the way to right for power up and then move to left after LED on, etc.
Problem with Aerohawk Rotary Head
The servos and swash plate control the cyclic angle of the side wings (also known as fly bar paddles) which in turn fly up and down to rotate the main wings around their axis. The main wings are in a ball bearing arrangement designed to let them freely change their angle of attack about plus or minus 20 degrees. In my unit parts 25 and 29 were rubbing and hanging up the wing rotation. Part 29 and 25 should be so free that any little breeze should be able to move the side wings up and down when the helicopter is parked. If not, cyclic response will be sluggish and/or the helicopter will go in the wrong direction in response to the cyclic. I disassembled 25 from 29 and filed down some mold lines on the inside of 29 and outside of 25. Also the ball joints at 24/31 needed to be loosened and the bottom ends of 24 needed to be filed down to avoid their rubbing on part 4. This kind of tweaking is apparently pretty common to all the small electric helicopters. Use following procedure at your own risk. It worked for me. To disassemble rotor head carefully pop parts 24 off of part 20. Then gently pull up on one end of part 29 while using a small screwdriver to push down on part 25 until one of the ball bearings (26) snaps out of part 25. The other bearing can then be slid longitudinally out of part 25.
There is a lot of discussion about how tight to attach the main wings to part 29. If they are fairly loose, they are supposed to set themselves to the right angle as you spin up such that both blades have the same angle relative to part 29. If you tightly attach them then you have to frequently make sure that they are exactly set at the same angle each time before you spin up or there will be major vibration probably resulting in “death wobble”. If the lift and therefore drag of one of the blades is different from the other and the blades are loose then they will not set at the same angle so “tracking” of the blades is critical especially if the blades are loose. If you mark the blades 1, and 2, remove the blades, and stack blade 1 on top of blade 2 you should be able to see if blade 2 has more curl and therefore more lift. Repeat with blade 2 on top of blade 1. If one blade is curled more than the other, one will have to be carefully twisted to adjust them. My blades had significantly different curl. See Goelz Piccolo site for more on testing and setting tracking. If you tighten the blades too much the threads will strip and you will need to add nuts to part 30. Actual balance (weight and center of gravity) of my blades seemed to be good as received. Raidentech (http://www.raidentech.com/) is a good U.S. source for Aerohawk parts. ( I found that for some reason it is extremely easy to bend the shaft on the tail rotor motor.)
Aerohawk transmitters are either mode 1 or mode 2. In mode 2 the right stick controls elevator (stick up/dn) and aileron (stick left/right). The left stick is for throttle (collective) (stick up) and rudder (stick left/right). The Aerohawk manual is written assuming mode 1 which is apparently used in Asia (left stick up/dn elevator, left/right rudder; right stick up/dn throttle, left/right aileron). There is no obvious way to change a transmitter from mode 1 to mode 2. The Aerohawk transmitter, probably actually made by GWS, does not have a training connector and can’t be used with simulators. Channel 1 and 2 servos are reversed at the transmitter.
I have both the G2 and Piccofly simulator software for PC. The Great Planes Realflight G2 Lite simulator (simulated transmitter connects to USB port) has great graphics and what is said to be a very realistic simulation of a 30 size glow helicopter. However, the Aerohawk is about ten times lighter than the 30 size, responds somewhat differently, and is more difficult to fly so G2 training is only approximate. The Ikarus IPACS Piccofly simulator (“Game Commander” simulated transmitter connects to game port) is said to be a very good simulation of a Piccolo. I found it to be very similar to actually flying the Aerohawk. If you can fly Piccofly you should be able to fly the Aerohawk, if not, your Aerohawk probably needs tweaking. The Piccofly Game Commander box (but not the G2 USB box) also works with the free Flying Model Simulator (FMS) software. The stock FMS helicopter models are very (unrealistically) easy to fly and I was unable to find a Piccolo model that works with the current version of FMS.
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All Forums >> RC Helicopters >> Electric RC Helis >> Aerohawk Setup Saga 
Aerohawk Setup Saga - 
LOTS of info! 
One question -- did you use any fluid lube on any of these parts during reassembly? At this time, I have just used a bit of dry graphite in the ball sockets, worked in, then blown off with compressed air. I'm worried about using a heavier grease/oil and attracting grit...