The servos can handle 6v, and if you are using the GP780 gyro, it can also handle 6v. But it looks like we have to look for something else, as the 5v setup was working fine earlier. The added resolution may help, but it looks like the issues is elsewhere !  All the 250s I have seen so far are running 5v setups.

Same with the governor... for basic hovering, these should be any critical factors at all.

In the crash, did you remove and remount the gyro ? 

All motors are a bit notchy in free spin, and it is hard to measure if that is bad enough from descriptions alone.

that's exactly what even am thinking that if the heli was stable before the crash,it should be now also...am baffled anwar bhai...and the gyro took no impact...actually the blades hit a wall and the heli crashed on its head....i changed the shaft and the feathering shaft and there were no other obvious damages! when i took it to hover again the wag started and since the its wagging the hell outta me!!@# unfortunately i dont have a spare gyro with me to swap and check! is there any other way i could see if the gyro is damaged!?
 

anwar bhai i managed to arrange for a hd camera finally....what should be the size of the clip to upload?

HD is fancy, not a must    Any resolution will work (480 or 360 will be easier to upload), the important thing is to illustrate the problem in ample light and at various zoom positions.

BTW, I forgot to ask !  Are you not able to hook up with other Bangalore experts like Rajesh or Adarsh ? Vinay also has lots of experience by now with helis !

i dont kno if you remember i mentioned to you that right now am completing my post grad in a place called davangere about 6 hrs from bangalore... i am in touch with rajesh and vinay but no one here right now to help me...i have bugged them enough over the phone already though i did think of meeting rajesh when i go to b'lore now, i have very less time and moreover i fly mode 1 so i cant send it across to them!

As i said, time to book new electronics for ur 450 GT pro belt. with Christmas arriving expect shipping delays. 

http://diydrones.com/profiles/blogs/phubar-an-open-source-heli

http://code.google.com/p/phubar/

Scrounge up the parts, and build one of your own !

Ya, but would be painfull, more than an FBL i would need a good place to fly 

hi anwarbhai finally i have 2 videos of my heli....camera work is ok...first try...there is a very slight wag after i fixed the gyro plate firmly to the main frame with some epoxy glue today...it was a little breezy so the gyro had some work to do..!delay at about 30%...hope you can figure out something..here are the links

anwar bhai after double padding the gyro and fixing the gyro tray firmly the wag is almost not there!i did some testing my self...if i land a little hard and take off again it vibrates lik crazy and if land it gently and hover it stabilizes!not able to understand what exactly is happening... if vibrations can affect a gyro sensitivity so much then how do these things manage on 700 size helis which vibrate like crazy!?compared to them am sure the 250 is nothing!

Sure i touched the tail boom before the crash and the vibrations were NIL. it was like the machine was off. lol.
Atleast compared to my HKs which vibrate like iam getting a shock  My gyros hold well though. I se slight drift some times, but thats why they are called HK stuff 

For small helis, one layer of GOOD double sided foam tape is enough to damp the frame vibrations.  On bigger helis, some gyro manufacturers insist that they be mounted with a metal plate in between two foam pads. The tail will have very small occasional vibrations, it will never be perfect as in the sims, and that is considered normal.  But yours was more than what can be called normal.


That worries me. If landing hard makes it vibrate, then either the foam padding is coming loose, or something inside the gyro must be getting affected.  We have multiple bad landings on our helis (especially while training for autos), but the tail behavior is consistent.  I remember the motor pinion on Santhosh's 250 came loose mid flight at about 10 feet (it was built with blue loctite as suggested in the manual, fixing again with red loctite worked better), and the heli fell from quite a bit of height and landed on the skids.  Nothing happened to the tail (behavior), or anything else on the heli !

More importantly, if the tail gets better AGAIN when you stop and fly, that means something internal to the gyro must be getting affected ?

Overall, I noted two more things...

1. Do noy fly so close to the ground, fly at 3 feet or above

2. Seems like you can use a bit more throttle, which will give you more tail authority.  I can see the tail struggling to keep up at times.  So increase your throttle curve at your hovering position (and if needed, compensate by lowering the pitch curve).

so you think its the gyro then!? cant afford another gyro now! i think ill have to send the gyro across to vinay or somebody so that they can test it on their helis! what do i do now bhai?and i kept it low coz it was a little breezy! dont need another crash right now

You said it is already a lot better with the foam padding.  Can you try a bit more head speed and see if it is better ?

Please do post some close up pictures of how you have mounted the gyro.  I had my suspicions about the gyro mounting, that is why I asked the question below earlier.


I don't know if it is the gyro... but if a hard landing can induce tail wagging, then we need to check/suspect the gyro mounting, the gyro itself, or some other part of the heli coming loose and inducing added vibrations.

il post some pics asap! i just hope this issue gets sorted out..hurts to seea 25k paper weight

Not at all paper weight   In fact, if you start doing forward flights RIGHT NOW, you will NOT feel any issues with the tail (assuming you got have the right throttle and pitch curves)

If a forward flight is done with a wagging tail, it sounds like "burr burr burr burr burr burr". Ask me how i know  . I used to fly a heli with a damaged ds480 tail servo which was wagging a lot.   But who cares, as long as it stays in air, I dont care if it wags or drifts, of course unless its a 25k investment and Iam learning 3D.  

BTW he has to yet practice nose left and nose right before FFF or just move the heli forward back ward with tail in orientation.

@doc
When u know the heli has already hit the wall, why do u want to hover in the same place?  , that too with a dog running around   LOL  

Exactly my point... that the wag is NOT huge. If it has already got better since the video was shot, that is even better. 

And I am very interested in knowing what additional head-speed does.

I doubt if he can try a FFF at this stage, and he would have used all the gyro foam I gave him. If he was here i would have tried the Align gel pad. But doubt that would solve the issue.

BTW my post number 1131 just vanished  Magic! Lol.

i thought you were talking about a lot of wag... this is not really bad, i think as anwar had stated try to increase the head speed more and the tail will get more authority... and i dont know if i had asked this earlier??... try to use the hole on the tail servo arm which is closed to the centre... this again will give a lot of authority to the servo as it will not have to work hard to find the gyro's centre point.. and pls fly a bit higher to get the right feel of the heli.. at least a mt in height

guys thank you for the response...just pray my heli gets better! and il try to mess around with the throttle and pitch curves again....maybe that might improve the tail...

sujju the arm is located at 5mm from the centre...and the wag seems better with a new outrage battery i got!

...whats the ideal pitch and th curve i need to have for the 250....right now they read like this
th curve-0,55,80,90,100
pitch curve-55(-4deg),75,85,95,100

That might be an indication that you need better head-speed !

Regarding pitch and throttle curve...  Pitch curve is a personal preference, and throttle curve is determined by the desired performance (against battery/run time).

I keep a straight 0-100 linear pitch curve for all modes, on all helis.  For beginners, I go for something like a -4, +4, +10 pitch range initially, and make minor adjustments during test flights. The intention is to get a stable hover a few clicks above mid stick.