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cheap built pusher

Started by azhaguvel, February 08, 2011, 02:58:44 AM

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azhaguvel

I am new to this hobby & this is my first built so dont mind about the poor build  8-)

I built this frame with all the cheap materials i found.

plane plan:
http://www.mikeysrc.com/FPV-Pusher-Plane.html

body is made of coro, actually these pieces are cut out of three aircel coro boards  :giggle:
For support instead of carbon fibre rods i used cycle wheel spokes. Control horns are made of plastic card of sim.
the total airframe costed me only around 50RS(hot glue,spokes)

electronic components
motor : http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=8621
prop : 5*5 which came with my AXN floater
ESC : 20 amps ESC which i salvaged from my AXN floater.
servos : 3 * 9gms hxt 900
battery : have 2200mah & 650 mah 3S(confused of which to use)

Weight without battery around: 500-600 gms (haven't weighed it, just a guess)


problem:
           The suggested prop in the plan is 10*6.But i have only 5*5.
           The CG is way back.  planning to add some weight in the front to make the CG at the point as per the plan. Any suggestions ??? :help:

azhaguvel

I would be very happy if experts in this form put a cheap built like this, with common available materials.

speedracer

i cant help you but i can sirely appriciate your work
nicely done.
Ideas Are Bulletproof.....

azhaguvel


azhaguvel

About the spokes. I have 4 four for the wing support which can be clearly seen. 2 in each of the tail piece(Inserted into the flutes after using hot glue on the tips). 1 in the fuselage. Since the aircel boards were little short i couldn't make the full wings with one piece so i cutted two identical piece & joined both with 3*10cm spokes at the top, middle & lower part. Then placed a piece of coro above it(the red strip in the middle of the wing). The servo for the elevator is placed close to the spoke in the tail.

avijit17basu


azhaguvel

haven't made a maiden. Think that the 5*5 prop are not enough. Ordered some 10*6 props from rcdhamaka, waiting for the prop.

prateek13

Award | OFNA Nexx8 | Art-Tech Edge 540T | Glidiator V2 | Hawker Tempest | Cessna Citation Jet
Turnigy 9X
FPV Platforms : CF Tricopter| HK EPP FPV | Bixler 1 | Bixler 2 | DJI Phantom 2 +H3 3D

medicineman1987

Hey, sweet model.. Love the super simple design.. I'm sure the Aircel people will be happy with you for all the free publicity.. :) Wish you best of luck with your test flight.. :thumbsup:
"The day you stop playing with your toys is the day you start getting ready to die.."

FlySky 9x (with ER9x,  backlight mod &  dual module hack) | Futaba SkySport 4VF (with 5th channel hack) | Glidiator - scratchbuilt 60" electric glider | SkySurfer | Scratchbuilt Tricopter | FT Nutball |  .46 Glow trainer (electric conversion in progress)

KALYANPRODHAN

I have a silly question.

Can anyone please tell about the rudder set-up of this model! I cannot understand from the pics.
The two servos are used for Aleron and one for elevator possibly.

Moreover, wothout battery positioning, how the CG can be achieved?
We have to unite and to prove ourself to make indigenous products as well as marketing / Canvasing them. I'm sure we must achieve success if we try unitedly.

azhaguvel

Thanks prateek & medicineman.

@ Kalyan

            This model doesn't have a rudder ;). check out the plans which i have posted at the start of this thread. About the CG i placed the 2200 mah battery in the battery slot(the small horizontal shelf in the fuselage) & checked the CG. reciever & ESC will be fitter to the side of the fuselage on the sides which they have been placed in the pic. Also before trying for the CG i used a double side tape to fix them on the side of the fuselage(In the pic the tape is removed).

azhaguvel

One of the member suggested me to use 'direct drive props(DD) dont use reduction drives (RD) props'

I dont know what exactly they are. Can some one explain

SunLikeStar

RD props are similar to SF prop (they might be same aswell 8-)), these work best on low kv motor, DD are suitable for high kv motor.

ujjwaana

Quote from: SunLikeStar on February 10, 2011, 02:18:32 PM
RD props are similar to SF prop (they might be same aswell 8-)), these work best on low kv motor, DD are suitable for high kv motor.

Ditto. RD=SF. Use motor in the 1800-2400kv range and put a 7x3 or 6x4 DD/Sports prop. Use a Prop Saver (rubber band) and not the Screw-in Prop Adapter and you would save lots of props on landings.
Futaba 8FG Super | HK-450v2 | FA-22 Raptor |AXN Floater-Jet | FunJet | Black Horse Edge 540 | Amp Master 015 | 2.3M Big Brother

azhaguvel

Please correct me, i might be wrong  8-).

yes i am using a prop saver  :P
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=10908

The holes were little small. I drilled it using a 1/8 inch drill bit

For the motor, the plan says i need 1000kv motor & mickey had a video for this plane, In that he specified this plane can carry 1 pound of equipments. That's why i decided to build this using coro since it still can handle the extra weight.

Also the prop from the plan is 10*6 so i have made an order from rcdhamaka(also have ordered 6*4 & 8*6).

Between i removed the reciever, ESC & battery. fixed a steel scale in the tip so that the CG came close to the point in the plan. Throwed it to test how it flies. It glided like a paper plane & landed with its tail first(tilted up).

Is this how it behaves or its the CG issue which is making it to land the tail first.

azhaguvel

Shifted the battery to top of the plane near to the CG point. now the plane glides & lands with its belly. Recieved the props today. 10*6 was gigantic & heavy. when i used it the thrust was too much, so i used 8*6 & feel that the thrust is enough to push the plane. Will do a maiden this week end.

azhaguvel

 :help: :help: :help:
To overcome the torque should the motor be projected up->right or up->left?
looking from behind the prop is rotating clockwise. currently i have made it up->left.

anwar

Looking from behind the prop, certainly a bit to the right, and a small bit down. The right is the most important aspect.
Hangar : Please see my introduction.
RC India forum and me : About this forum.

azhaguvel

anwar can you elabrate more on why i should make it down->right.

what i thought was, looking from behind
The propellor is rotating clockwise. The torque will try to rotate the plane anti-clockwise. so if i make it up->left since it is a pusher the force will be at an angle 45 deg which in turn tries to bring the plane back to its horizontal position.

anwar

Hangar : Please see my introduction.
RC India forum and me : About this forum.

azhaguvel


anwar

For pushers, what I remembered was that it is dependent on the position of the motor in relation to the wing (above or below).  If the motor is above the wing, you need to tilt the prop side of the motor up so that the thrust line of the motor falls in front of the wing (and vice versa). 

In your model, it seems like the motor is pretty much flush with the wing, so you may not need much of anything.  Please wait for more experienced folks to answer, as my experience on this is limited ;)

With the motor a bit below the wing, I think you may need to point it a tiny bit down, or just leave it alone !
Hangar : Please see my introduction.
RC India forum and me : About this forum.

anwar

BTW, you said your prop is rotating clockwise, looking from behind. Not sure that sounds right, if you are using a true pusher prop.
Hangar : Please see my introduction.
RC India forum and me : About this forum.

VC

Azha, wish you all the very best for the maiden. We are all rooting for you. Well done!
Growing old is mandatory, growing up is optional!

azhaguvel

chees.. thanks VC  ;D

@anwar
I only have seen an AXN floater blades which i have. i took it out & checked. :headscratch: but that also rotates clockwise looking from behind.