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8/3/2019 In Detiail Making of Rc Helicopter
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MAIN BODY:
The material that I uThe material that I use to make the main body of the helicopter
would make you feel surprise. It is the circuit board ( after removing the copper layer
) that purchased from electronic shops. It is made of a kind of fiber which gives
abnormal strength to it
The circuit board is cut to the rectangular shape as above( 98mm*12mm). As you can
see, there is a hole on it which is used to house the main shaft holding tube as below:
The main shaft holding tube is made from a white plastic tube (5.4mm*6.8mm) and
two bearing (3*6) are installed at both ends of the tube. Of course, the ending of the
tube are first enlarged in order to house the bearing firmly.
Up to now, the basic structure of the helicopter is completed. The next step is to install
the gear as well as the motor. You can take a look at thespecificationfirst. The gear I
used is from Tamiya gear set that I bought long long time ago. I drill some hole on the
gear in order to make it lighter and have a better look..
http://www.angelfire.com/blues/heli_project/spec.htmhttp://www.angelfire.com/blues/heli_project/spec.htmhttp://www.angelfire.com/blues/heli_project/spec.htmhttp://www.angelfire.com/blues/heli_project/spec.htm8/3/2019 In Detiail Making of Rc Helicopter
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Would you think it is just too simple? Well, it is really a very simple design as the tail
rotor is powered by a separate motor. This eliminates the needs not to construct a
complicated power transfer unit from the main motor to the tail. The tail boom is
simply fixed on the main body by 2 screws together with some epoxy adhesive:
For the landing gear, 2mm carbon robs are used. Totally 4 holes are drilled on the
main body ( each end 2 holes ).
All the robs are glued together by instant glue first and then by
epoxy adhesive.
The skid set is made from balsa. They are very light and can be
shaped easily.
Swashplate is the most sophisticated part of a RC helicopter. It seems to be a simple unit of a factory on
However, it is a whole new thing of making one by yourself. Here is my design based on my own little
knowledge about the swashplate. What you need includes:
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1 ball bearing ( 8*12) 1 plastic spacer (8*12) rod end set ( for holding of the aluminum ball in the swashplate ) aluminum ball ( from ball linkage set 3*5.8 ) aluminum ring
epoxy adhesive
The rod end set has first been cut into a round shape. It is then inserted into the plastic spacer as shown
below:
Make sure that the aluminum ball placed in the rod end can be
moved freely. 2 holes were drilled on the plastic spacer in order to
house two screws that used to hold the ball linkage.
The back of the swashplate In my design, the swashplate is fixed on the main shaft. Thiis simply done by applying some glue between the aluminu
ball and the shaft
# be careful when applying epoxy to this tiny unit or you would get every part being
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glued together.
My instructions are too confusing? Here ismy draftof the swashplate which might help you. I still find
that my design is a little bit too complex. If you have a better design, please let me know!
For the rotor head, I choose the same material as the main body - the circuit board.
First of all, I have to claim that the rotor head must be sturdy enough to withstand any
vibration or it could be very dangerous.
The control system I used here is the Hiller system. In this simple control system, the
cyclic controls are transmitted from the servos to the flybar only and the main blade
cyclic pitch is controlled by the flybar tilt only.
The first step is to make the middle part:
It is actually a 3mm collar which can be fit into the main shaft. A 1.6mm bar is
inserted horizontally into the collar. The above unit makes the rotor head movable in
one direction.
http://www.angelfire.com/blues/heli_project/swashplate_hand.jpghttp://www.angelfire.com/blues/heli_project/swashplate_hand.jpghttp://www.angelfire.com/blues/heli_project/swashplate_hand.jpghttp://www.angelfire.com/blues/heli_project/main_body.htmhttp://www.angelfire.com/blues/heli_project/main_body.htmhttp://www.angelfire.com/blues/heli_project/swashplate_hand.jpg8/3/2019 In Detiail Making of Rc Helicopter
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There are two holes just above the collar which is used to, as you can see, house the
flybar. All the parts that I used was first fixed together by instant glue. They are then
fixed firmly by tiny screws (1mm*4mm) as shown below. In addition, I add epoxy
adhesive. The rotor head will spinning at very high speed. Never overlook the
potential for causing injury this little machine has if anything got loose. Safety is
paramount!
As I mentioned before, the Hiller control system is used in my design. All the cyclic
controls are transmitted to the flybar directly.
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There is a metal bar ironed perpendicularly to the flybar. It holds the metal ball of the
ball link in position. Here is how the ball link is made:
The rob ends are shortened and a metal bar is used to connected them together. the
metal bar should be inserted deep into the rob ends and fixed with epoxy adhesive.
In addition to the ball link, an "H" shaped anti-rotating unit is a must for the control
system. It helps to keep the ball link in position. The materials needed are showed inthe above photo.
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In order to stop the lower part of the
swashplate from moving, an anti-rotation
unit is also needed here. It is simple asmall board with two pins inserted on it.
The tail rotor consists of a motor, tail blades, tail shaft holding tube and a blade
holder. The tail control is managed by changing the RPM of the tail motor. The
drawback of this kind of control system is its sluggish response as the rotor pitch is
fixed. However, it makes the whole design much more simpler and reduces a lot of
weight.
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In an ordinary R/C helicopter, the gyro work together with the tail servo. However, in
this design, the gyro has to work together with the ESC (electronic speed controller).
Will this work??? At the beginning, I try this with an ordinary gyro ( the large one for
the gas helicopter). The result is really bad that the RPM of the tail rotor changes fromtime to time despite the helicopter is standing on the table. I buy a micro-gyro later
which is specially designed for small electric helicopters and to my surprise this
works great.
Here is the measurement of the tail blade. It can be shaped easily
from a 2mm thick balsa. the tail blades make an angle of ~9on the
blade holder
The photo shows all the things that the tail part consists. The two
balsa blades are hold by a hardwood holder which helps to give afixed tail pitch. It is then secured on the gearwheel by 2 screws.
The motor is simply glued on the tail boom by epoxy adhesive
and the tail shaft holding tube with the same way on the motor.
The tail blade is made of balsa. They are covered with heat
shrink tube in order to reduce the friction between the blade and
the air.
The pitch and the weight of the two blades must be exactly the
same. Tests must be performed to ensure that no vibration occur.
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Only two servos are used in my design. One is for the elevator and the other one is for
aileron. In my design, the aileron servo is installed between the motor and the main
shift holding tube. In this way, the tube has made use of the sturdy plastic case of the
servo as one of its supporting medium.
This arrangement gives extra strength to the
main shift holding tube as one side of the
servo is glued to the motor while the other
side is glued to the tube. However, the
mobility of the servo as well as the motor is
lost.
In order to make the whole structure sturdier, an additional support is added to the
main shift holding tube. It is also made from circuit board with some holes drill on it.
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Receiver
The receiver I use is GWS R-4p 4 channel receiver. Originally, it is used with micro crystal.However, I can't find one which fit with my TX's band. So, I give my try to use the large one from
RX. It eventually works great and no problems have occurred up to now. As you can see in the abo
picture, it's really big when compared with the micro receiver. The receiver is only 3.8g ( extremelight weight ) which is very suitable for indoor helicopter.
#Although the receiver has only four channels, it can bemodifiedto a five channel RX.
The tail Esc
Here you can see the speed controller that is used in my helicopter. It is placed at the bottom of the
gyro (see the photo below). Woo!! Really small size with only 0.7g. It is a JMP-7 Esc that I bougfromeheli. I really can't buy one from local hobby shops here in Hong Kong. Also, this tiny Esc
works great with the gyro. I just simply connect the signal output of the gyro to the signal input of
Esc.
The micro-gyro
http://www.angelfire.com/blues/heli_project/collective.htmhttp://www.angelfire.com/blues/heli_project/collective.htmhttp://www.angelfire.com/blues/heli_project/collective.htmhttp://www.eheli.at/http://www.eheli.at/http://www.eheli.at/http://www.eheli.at/http://www.angelfire.com/blues/heli_project/collective.htm8/3/2019 In Detiail Making of Rc Helicopter
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This perfect micro-gyro is made by GWS. It is temporarily the lightest gyro that I can find in the
world. Unlike the previous GWS gyro that I used in my gas helicopter, it is very stable and the cenpoint is very accurate. If you plan to buy a micro gyro, it would certainly be a good choice for you
The tail motor
The motors in the above photo are 5v DC motor,micro DC 4.5-0.6, andmicro DC 1.3-0.02 ( fromleft to right ) In my first attempt, the micro4.6-0.6 is used. The motor burns out quickly ( or I shousay that the plastic component in the motor melts) as the power demand of the tail rotor is much la
than that I expected. At the moment, the 5v motor is being used in my helicopter which is still in v
good condition.
The current tail motor is a 16g GWS motor which provide much more power. For more informatio
http://www.wes-technik.de/English/Motors3.htmhttp://www.wes-technik.de/English/Motors3.htmhttp://www.wes-technik.de/English/Motors3.htmhttp://www.wes-technik.de/English/Motors-submin.htmhttp://www.wes-technik.de/English/Motors-submin.htmhttp://www.wes-technik.de/English/Motors-submin.htmhttp://www.wes-technik.de/English/Motors-submin.htmhttp://www.wes-technik.de/English/Motors3.htm8/3/2019 In Detiail Making of Rc Helicopter
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please go to the page "flybarless CP modification II"
The main ESC:
The first photo shown above is a Jeti 050 5A brushed electronic speed controller. It was used tocontrol the speed 300 motor in my helicopter before. As the speed 300 motor is now replaced byaCD-Rom brushless motor, the Jeti 050 had been replaced by a Castle Creation Phoenix 10 brushl
ESC.
The following diagram shows how the components are connected to each other. The connections at the
receiver is not in order. The GWS R-4p is originally a 4-channel Rx. It is modified in order to provide an
extra channel for the pitch servo.
In a fixed pitch design, only 2 servos are needed. A computerized Tx is needed as the the tail control must be mixed with the throttle control. For a
http://www.angelfire.com/blues/heli_project/collective_2.htmhttp://www.angelfire.com/blues/heli_project/collective_2.htmhttp://www.angelfire.com/blues/heli_project/collective_2.htmhttp://www.angelfire.com/blues/heli_project/brushless.htmhttp://www.angelfire.com/blues/heli_project/brushless.htmhttp://www.angelfire.com/blues/heli_project/brushless.htmhttp://www.angelfire.com/blues/heli_project/brushless.htmhttp://www.angelfire.com/blues/heli_project/collective_2.htm8/3/2019 In Detiail Making of Rc Helicopter
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Piccolo micro helicopter, this task is performed by the Piccoboard. For my design, this is done by
function "Revo-Mixing" in the Tx.
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