Hi Guys ,
I have been supplying motors , props ,spares for college students making QUAD rotors recently .

Any one made it sucessfully in India  ?

I found this thread  and layout on rc groups  thought I will post it but its beyond my understanding  

May be some of the techos might find it interesting

http://www.rcgroups.com/forums/showthread.php?t=614041

Sai

not quad rotor but i use some kind of the same setup for my twin rotor v22

E.V.Subramanian

do we need to use mixers   even if our tx is capable of mixing the channels  

can't we just mix the channels from tx

Tried the combination  of V tail Mixers  and Gyros to see if the concept works with  some Brushless  Motors I had , the elevator throttle  segment works   will shift the same 2 motors to the Aileron rudder side  some day as time permits  and check it out .
I am trying these motors  without an airframe only checking if the system works , if it does then fitting on to an airframe should not be  a major problem.

Hope to keep  the updates coming .

sai

if we create a quadrotor with each arm 25 cm from the centre which is made of balsa and with the following electronics,will it work?

electronics to be used:-

http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=6293&Product_Name=ZIPPY_Flightmax_1800mAh_3S1P_20C x4 for powering the motors

http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=4852&Product_Name=TowerPro_BM2408-21T_/_18A_BEC_/_1047_Prop_Combo x4

http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idproduct=10113 x3 as a gyro

http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=5247 as a prop

http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=5249 -for counter rotating prop

http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=4170 x3 as a v-tail mixer

http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=3735 as bec

http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=6519&Product_Name=ZIPPY_Flightmax_1300mAh_2S1P_15-25C this for powering the bec

and a 6ch reciever

will this work???

can we use 2 mixers and use 1 mixing from the tx?

The previous answer stands.  How will you get the output of the gyros that are on the plane, back into the TX which is in your hands to be mixed ?  Remember that the mixing in the TX is of the stick positions.

ok what abt the stuff that i posted...can it be used.....?

Ankur - Building such an aircraft is all about experimentation.  People will be hesitant to say YES or NO to your question, unless they have built one and flown it themselves.  Even in that case, one person's success may not directly translate to someone else's success due to changes in material used, difference in final AUW etc.

So you have a design that Sai posted, and it is upto the individuals to experiment.  For example, the tricopter I saw on our field was built very light, and all 3 motors were driven from a single lipo, and there was no separate BEC.  So when you post such a "bill of materials" (fancy term for list of items you need to accomplish something ), people will really be worried about getting involved (at least that is what I honestly felt when I initially saw your post).

Think about simplifying everything, and have fun with the experimentation.  The big concern is the main  power system (motor/ESC/prop) selection, and it looks like you are OK on that part.

OK actually i plan to build one in my summer holidays if i gather enough fund for that...
anyways thankx.

have put all the things in one place for quick access.

http://pankajwasv.blogspot.com/

all the GYAN you need to build a quad rotor ,rest here are senior members(VC sir,RAO sir,anwar bhai,sahil bhai),you can always take help.

just wondering how can we counter rotate brushless motors [ like brushed ones can be reversed by reversing the polarity ]
since we need to use 2 conter rotating props then we need to counter rotate the motors too[or the net thrust will be zero as both set of props will swinging in same direction and they will will push/pull air in opposite directions hence cancelling each others thrust]
hence i arrived to this question....

-Ankur

by using CCW/CW propellers.This way they can cancel each others torque and remain stable.

what are ccw/cw props??
secondly as per the mixing diagram posted by mr.sai it is necessary to counter rotate two motors so how can we counter rotate them??

CW-Clockwise
CCW- Counter Clock wise

Quads use props in counter-rotating pairs. Most common normally used props on models are CCW rotation, also called tractor props. When looking at the front of the CCW rotating prop the air is propelled behind it. The common orientation is the front and rear using the CCW props and the left and right using the CW, or pusher props. This may or may not be reversible, i.e., CW props on front and rear and CCW props on left and right, in your setup utility depending on the version of quad you fly. If the front, rear, left right prop orientation is not selectable via the setup application, then the props must be mounted the way the flight control board requires them or the quad will not fly and possibly will flip when throttle is applied. The CCW(tractor)+CW(pusher) prop sets are not commonly available, but online stores do have them.

Recommended props:
--APC1238: ~$8pair. 18.7g.
--APC1365: ~$12pair. 26g.
--APC1447: ~$12pair. 25g.

ok i have already gone through them and  i know it
my question is that is just putting these props on a bl motor sufficient?
i don't think it is
i think we will need to turn the motors also in the opposite direction and this is my question-how to do it[turn it in opp. direction]??

For a brushless motor, just interchange any 2 of the 3 wires. But to get the desired effect, you will also have to mount two of the motors upside down, I think.

I dont think you would need turn the motor in opp direction.The CW/CCW props would do the work i guess..

if you mount the the 2 motor upside down then you will get longer battery life.If you rotate the motor in opposite of its natural roation (CW/CCW) your battery life would suffer.Some member of rcgroup posted it a while back.Cant find the thread.
But i still think if we use CW/CCW props we wont need to rotate the motors in opposite direction.Correct me if am wrong.

I was talking about achieving the same results using the same type of props (instead of having both CW/CCW).

If we use same props for all the motors and rotate 2 motors in opposite direction.Then battery life might suffer.Read it in rcgroups.
So the best way would be to put 2 motors in upside down as you pointed already.

Let us say we use same type of props with all motors pointing upwards (so they are all pushing air downwards).  Now if we rotate the props on two of them in the opposite direction, those two will push air in the opposite direction (which is upwards), which defeats the design ! This is what drives the "two motors mounted upside down" setup

You can see it in action here, in the link Sai posted initially itself : http://www.rcgroups.com/forums/showpost.php?p=6596903&postcount=4

I am planning to build one soon, will know better after that !  Got all the parts today, it is only a matter of time now (so many things to build)

Brushed motors have a preferred direction because the commutation timing is set mechanically. I don't see how brushless motors have this issue. Will be interested in the link if you can find it again.

Hi
  For the quadrotor we need 2 tractor and 2 pusher propellers. rotor.co.in is good source to get them, but they also have low stock. So i'm not getting 8*6 or 9 inch pusher propellers there.. Any other sources in India?