450 450 Tip Over Fault

Graham Lawrie

Graham Lawrie

Well-Known Member
Going to make a video to follow tomorrow. I spooled up keeping a close eye on the swash plate. At half throttle I noticed a jerky movement and on closer inspection the swash had tilted forward. I spooled down put throttle hold on checked all movement, everything moved as it should. I spooled up again and left it at half throttle, slowly the swash started to drop forward. I put throttle hold on and it spooled down, swash remained tilted forward until the final few rotations then it levelled ou????
 
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pvolcko

Well-Known Member
Assuming a fbl setup, notice any vibrations? Sounds like the gyro is picking up vibes which is causing it to pitch. Of course, with these flybarless gyros you're not supposed to leave them sitting on the ground at half throttle, near take off like that for exactly this reason. Get it spooled up and get it off the ground.
 
Graham Lawrie

Graham Lawrie

Well-Known Member
Hi Guys, It was going to tip at take off,no signs of vibration, and no trims on TX or mixing. I will put a close up video on at some point this weekend:)
 
Tony

Tony

Staff member
These gyros don't like to be run on the ground. When you do, there may be a slight tip in the swash and it's going to keep adding cyclic until it gets to that point.

This gyro wasn't doing that for the first flights, what did you do different?
 
Graham Lawrie

Graham Lawrie

Well-Known Member
Tony, the only thing different is new links, feather shaft and main, and 3.1. I am going to re-flash it tomorrow. Uploading a video 34 minutes to go then you can see what i mean:)
 
Tony

Tony

Staff member
Hm, that is interesting. I couldn't really see the swash in the beginning of the video though. Um... Yeah, I would set your pots to 12 O'clock and reflash the firmware. Then set the pots to 105 per the computer program and see what it does. As stated before, these things just do not like sitting on the ground running, and they don't like training gear even more.

Have you balanced your blades per the video that I just uploaded this week? If not, have a go at it and see if that doesn't help anything.
 
Westy

Westy

LEGEND
did you do your DIR on flat ground? are you initialising the heli in the same place it is sitting there?... what happens if you do a circle on the cyclic and return beck to centre? does it still go to the same position?

- - - Updated - - -

Take your training gear off and try it (do not take off) up to half throttle..... see if it still does it. If so ... I would say the Gyro is picking up the vibes off the landing gear ... and will settle in the air! you will just have to pull a bit of rear to get it off the ground.

See what the no LG test does!
 
Graham Lawrie

Graham Lawrie

Well-Known Member
Tony, blades are balanced lovely.swash nice and level at start.In the video I stopped it using throttle hold, you can see how far off it was. I set it up on a table in the house Westy that is nice and level. I will try the landing gear off first, then the re flash.
 
Tony

Tony

Staff member
DIR mode doesn't need to be level. The swash just needs to run perpendicular to the main shaft. The Ikon is what needs to be perfectly level with it's auto stability.

I just tipped my 450 over about 10 minutes ago. I needed to see if I had fixed the issues with the tail and if it would fly. Windy as hell and dark, I took it outside and spooled it up. It spooled up just fine, but started tipping to the right. I couldn't save it and the blades hit the ground at about 50% throttle, NOT under power. My issue was the servo plug that goes into the Rx. Just something to check. Make sure the METAL pins are pushed all the way in, and not just the plastic plug.
 
Graham Lawrie

Graham Lawrie

Well-Known Member
I have just flashed the 3gx , pots back to 12, then tweaked them to 105 ail/ele and removed the training gear , same result, but bouncing worse. I removed the main blades and the bounce was not as bad, so need to check them again, but the strange thing was the elevator servo was moving up and down causing what i have seen.

To all intents and purposes it is not an old servo.(DS410M) It came with the kit. But boy was it chattering up and down. My feelings now are that the servo could be faulty?
 
Tony

Tony

Staff member
Either the servos or the gyro. I noticed on the 600 that the elevator servo would twitch every now and then when I was setting up the head. Makes me a little nervous to put it in the air.
 
Westy

Westy

LEGEND
can you change the servo into another position and see if it follows the servo.

Mine Jits up when doing DIR also .... only once every 40 secs to 3 mins ..... not sure what that is ... but holds steady when in the air!
 
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Tony

Tony

Staff member
I couldn't watch that video. Dude need a serious fingernail cut and he is talking about stuff that is not even on the screen lmao. I don't know about anyone else, but I have a screen where I can see what I'm shooting...
 
Graham Lawrie

Graham Lawrie

Well-Known Member
Update: I went to check everything over with the intention of swapping servos. There was a vibration with all blades removed:(
I removed the head and main gear and checked the head. The feathering shaft bolt had started to come undone, like it did before when my blades popped off:(

As this had happened before I know I had been extra cautious on the rebuild.So not sure why this is occuring

As with the last time this happened I have changed the feather shaft and main and bearings for new as a precautionary measure without checking the old set. I think this is good working practise to renew all at the same time, then check over the old parts after, bin what is no use, and mark what is useable spare for emergency use(while waiting for parts).

I then spooled up and watched the servo still twitch but not as bad. The swash stayed level, even though it was twitching on the elev. servo.

I have re-fitted the blades and am waiting for a dry spell to spool up without training gear if there are no issues at this point I will refit the training gear and go for a hover:)
 
Tony

Tony

Staff member
Are you cleaning the bolts and the inside of the feathering shaft with alcohol before putting the bolts in it with thread locker?
 
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