I just bought walkera 5g4 Heli,
I need a training gear for it.
where can i buy it?? in Delhi or online

Not sure if you need further training gears on these small coaxial ones. 

If you insist, these should work.

http://rotor.co.in/show-detail.asp?prodid={4B9B0D8E-7C72-433A-8287-2393019EDF09}&pn=1
http://rotor.co.in/show-detail.asp?prodid={80179B9D-2F24-4878-96EA-D11274F616AF}&pn=1

Quote from: tiwari on May 26, 2010, 01:29:39 AM
I just bought walkera 5g4 Heli,
I need a training gear for it.
where can i buy it?? in Delhi or online

why dont you make on your self with ping pong balls (table tennis balls and wood or wire).. just google and you will find out..

Absolutely ! It is a shame that I did not suggest that

Thanks, friends
I have already made one with thermocol and cheep thin chop-sticks.

but I had broken my landing gear before making this one,  ,  walkera 5g4 has a plastic, cheep looking, fragile landing gear.

Asked delhi model craft, he has a spare landing gear for Rs 280/-

Wish would have asked u guys before investing.

HI GUYS--- food for thought
a zero cost training kit for rc reli-- 3/4 rotor dia of ur heli in cross shape from thin bamboo. stick one inch foam ( thermocole or EPP) balls- insert them with glue. fix with ordinary rubber bands on the skids, less flying time, but very safe. i ve used it on the electric rc Alloy shark. Fly for 4-5 days with the kit, then off with it, see the picture. happy landings......

Do you have pictures of the actual skids you made ?

If you ever doubted Telepathy, here it is Once and For All!!! I just thought about posting some pictures of a Training Gear that I just constructed about an hour ago. I see this post and am absolutely speechless. This is what I made BEFORE I saw this post. Please check the colour of the foam balls!!!!!

Materials - Bamboo sticks strengthened with cello tape, foam balls and rubber band.

Foamy, my friend - let's keep in touch........

Cheers!

VC

Anwar shab, I dismantelled the training gear, however i'll make them again, but need some time. Yes, a woed about the foam balls- for the novice-don't use pingpong balls-they only give shape, no advantage. Just cut a 1 inch/1 inch block of high density thermocole, draw 1 inch dia circles on 2 sides (90 Deg), take a medium sand paper and just appx shape it spherical- thats all. VERY EASY.... PRABHAT 

HI TIWARI,
get in touch with me in delhi after 04 Jul. My contact no 9810316595,25674257 & if u ve not flown ur bird yet, hang on, we will discuss before u go solo at delhi.....prabhat

Why is a training gear required for a co axial heli? Are they so twitchy? Can the blades get enough elevator/ailerons so as to topple over?  

But that sure is one big size for a co axial.

Yes it is a big co axial. Lucky to have got her. Maidened her today and needed a lot of trimming to get her going right. I am a novice pilot and need a lot of practice to get it right.

Yes you are right, she kept toppling over.

Regards,

VC

hi vinay,
the problem with these chinese electric rc helies is that they dont have any servos, so no cyclic and collective control. Smart way to tackle the torque effect ( newtons 3rd law) is with a coaxial rotor. By differentially varying the fixed pitch rotor speed u achieve yaw control. Pitching is using a small fan at the end of the tail boom (small force X long distance= change in force at the CG). Now the problem with these helies is that as the batt gets drained the rotor rpm keeps dropping, thus the differential trim on the TX needs constant adjust ment and the chopper keeps going round and round if u've wondered. That my friend can casue a prang -by not appriciating the situation and breaking  the rotors. But , a novice must use a trg kit before starting to fly.

prabhat

OK, that means, these helis can only move forward/backward using the motor at the tail(fan facing upwards), but cant move to the left/right (like left/right aileron of CCPM.) right? BTW, if there is no fan at the tail end, how do these helis move forward/backwards, w/o cyclic servos?

The left/right is by differential rotational. If u've noticed, the coaxial rotors rotate in opposite direction. Ideal steady flight condition means that both the rotors are maintaining steady RPM,therefore at zero differential. When u enable a right/ left movement, the reciever electronically, reduces the corresponding rotor RPM, thereby due to the Torque effect( equal and opposite reaction) achieves the desiredinput result or by itself due to depleting current in the batt pack which needs to be controlled by u via the TX. Just as an input, in a conventional singal rotor heli, the vertical fan at the tailboom is an antitorque device as well as a yaw(directional control). The steadiness of the yaw is governed by the gyroscopic rigidity that the tail rotorprovides which is dependent on the distance from the main rotor axis, tail rotor RPM and the mass of the tail rotor. This torque has been compensated in the chinese electric helies by simply having another coaxial rotor.  Another important point to notice is a fly bar ( a rod centrally mounted above the coaxial rotor heads holding some heavy metal cylinders). This device acts as gyroscope, ie, it is rigid rotating mass. If u notice this has been linked to the upper rotor head at an angle and if u move the flybar, the upper rotor axis also tilts. In a dynamic state(while rotating) the flybar and the upper rotor form two dependent discs. What it means is that any disturbance that woud cause th rotor plane to tilt( causing change of flight condition) is prevented by the fly bar as it is a rigid gyro ( just like ur bicycle wheel,so steady that u can ride it with ur hands off). But if the distubance is for a while steady, tilting the fly bar disc, te rotor will drift to that direction till u correct it(Check). If not checked on the TX, the heli can rool over and prang. I hopre this input will improve understanding the heli dynamics.......prabhat

Just added a desi training gear(made of bamboo sticks) to my 5889 4ch heli as instructed by VC bhaiya. I found out that there's another advantage of this training gear.

Due to these long bamboo sticks, the moment of Inertia about an axis parallel to the ground passing through the rotor blades is increased and hence, it becomes difficult for the heli to tilt sideways and/or forwards and backwords, thereby increasing the stability in the roll and the pitch.

In simpler terms, the heli now has to move the long sticks to tilt which it finds difficult to do so, and guess what now I can hover my heli at a single place and I'm loving it whereas for the past few days, I was having difficulty doing so. I really recommend it to the beginners, it makes the heli much easier to fly and easier to learn and once hovering under these circumstances is mastered, then the training gear can be removed.

Now, there's another point to this; I think there is a fine line for the length of the training gear(which also depends upon the mass of the sticks you use), if it is made too big, then the heli will become overstable, in other words, the heli will not move even if you want it to move, which is not what is desired and secondly if it is too small then it wont serve the purpose. So, for a particular length the outcome is the most favourable, now that can be calculated by calculating the torque about the axis of rotation passing through the cg of the heli, parallel to the ground(those sorts of things which i used to do before my iitjee  ), it can also be found experimentally(by trial and error). I luckily seem to have found the sweet spot(or close to it) in the first time. As suggested by VC bhaiya, I made the stick 2inches longer than the diameter of the rotor blades. It is working like charm for me. 

Thank You so much VC bhaiya, you made my day 

Despte providing a good resistance to crash, does it provide any additional stability as well??