hey jeevan ... i can help with tricopters.. but quads are a bit different... well.. still lemme know throgh pm if u need help

Hi. this is Pritam final year be student. I'm doing project on tc helicopter. so can someone help me in building helicopter. thank you.

[Moderator Edit] Topic merged. Please take a look at existing topics and they will help.

sorry.typo.I meant rc helicopter.

Hi...........
everyone
i want to buy a rc helicopter as me a beginner so pretty confused which one to prefre......
pls help me select one....
and what is the difference b/w 3 channel and 4 channel helicopter..............

Jok..choosing an Rc helicopter is, based on the money, and interest that you have..a simple little heli with gyro is a best machine, for beginners..but yes by flying this little machine, means, you may not become a best RC professinal machine pilot..a two channel heli means, that you can lift it up, and hover, while can control in to left and right, with altering its tail rotor speed to high and low..in a simple three channel heli, you can lift it up, hover, can turn left and right, and can also go foreward and reverse..and the channel use varies when we enters in to big machines..these big machines employs complicated swash plate controls, mixing, alomg with throttle ratios and gyro, all are employed..its all complicated..
so, as a beginner, you can choose a micro heli, at first, with a gyro, that helps you in flying a lots..most of the time, these types of machine came with twin contra rotating props, as main rotor discs, while a little one at rear end for foreward and reverse motions..the left and right turn controls are attained by altering the rotational speeds of main rotors..so, at first go for a micro heli..with gyro..this costa about a 650 to 1200 Rs /- around..and please check while purchasing, for any gear problems, and make sure this one is hovering well..

4 channel Fixed Pitch helicopters are very good for learning

Roopesh sir I completely agree with what you've mentioned.. I as a beginner have tried these micro heli's and believe me even they seem complicated to fly. I have already messed up 2 of them while trying to fly them indoors and now looking to get a third one...

Punty..if so, because of these things.. at first make sure the purchased heli is one equipped with a GYRO.. you can make sure that the gyro is working, by holding it in palm, while locking its landing skid by fingers, while main rotor rotaes, by shaking it left and right in a fast manner.. in these movements, speed of the main rotors must changed, and you can hear the variation of speed by ear.. if so, we can decide that the gyro is responding.. and in some good heli, there must be a potentiometer to adjust the sensitivity of gyro.. if all are ok, try like this..

place the heli in your palm.. hold it about your chest height.. make sure an eye protection.. make sure no fans are switched on..and look for any wind.. slowly increases the throttle.. now it must hover just over your palm.. if it tends to turn any direction, you can make it straight by turning the trimmer potentiometer, on Tx.. now watch the hovering.. and gently increase the throttle.. practise hovering.. and then can go for directional flights.. wind and the stronger lights are the good enemy of these crafts.. and cut throttle instantly, that if you feel it as crash..  falling ground will not hurt much these tiny machines.. go for a good heli.. 

@ Roopesh sir.. Thanks a lot for the valuable advice.

try with patience..

what are the good heli kits avilable in india. what does it need addition to body. i think motor,esc,servo and rx/tx. anything more? and what is this 450 and 500 nos.

My heli has been sold. I received another ModelArt 3ch heli for repairs.
Here are a few pics :

Few more :

The heli is fixed
I faces two problems. I will log these problems and the solution here. I hope it helps

Issue 1:
Observation - The lower blades rotate as expected but the upper blades do not. The upper blades rotate slowly. The speed of rotation is not proportional to throttle input. The heli would rotate uncontrollably about the axis passing through the rotor shaft.

Problem : The upper blades are attached to a plastic "blade holder , flybar, links" assembly. This assembly had become loose i.e. it did not fit snugly on the shaft. The blades can be held stationary while the shaft rotates as expected.

Solution: I glued the assembly to the shaft using quickfix. The shaft which rotates the upper blades passes through another hollow shaft which rotates the lower blades. I applied oil at the opening of the hollow shaft where the upper blade shaft enters to avoid gluing the two counter-rotating shafts together.

Issue 2:
Observation: The heli would take off as expected but suffers from severe toilet bowl effect. It flies around in circles uncontrollably and eventually crash.

Problem : The flybar was not free to move. The links connecting the upper blade holder to the flybar had moved past the ball ends. The heli was unable to stabilize in flight.

Solution: I moved the links back onto the ball ends. The pic named ball_links shows where the link should ideally be (blue circle) and where the incorrect position where link was (red circle). The links were in the incorrect positions at locations A, B, C and D causing the flybar to be stiff and perpendicular to the heli at all times.

Pic two shows the ideal flybar position (or angle). With the ball links placed incorrectly, the flybar stays perpendicular to the heli.

Thanks for this detailed post Rajath.

I had a very similar helicopter one year back which had the same "toilet bowl" issue. I was too damn ignorant those days, I gave the heli to my friend and he ripped it apart beyond recognition !

Wish I had the heli with me now so I could check what has mentioned in you post.

Welcome Ebin
The heli is not fixed yet. It does not have power to fly higher than few inches off the ground. The lipo voltage looks OK. I will drain the battery, charge it to full and check again. Any thoughts on what the problem could be welcome