Gp790 shuts down

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Hi.

Rebuild my 450 plus today after a small crash, changed mainshaft and blades. Also
changed rotorblades cause they were looking bit bad after strifing sand on the field i fly.
They didnt have 59.6mm blades so i put a couple of 61mm blades on it.

So to the real problem, out of no where in a hover i notice the tail gives me a wiggle and when i give it more power the heli starts spinning. Turns out the gyro-light is out and the servo dont react. So i land it, power it down and unplug the battery, and when i replug the battery the gyro fires back up and all seem normal til it happens again a few mins later.
Unplugging and replugging the battery rearms it. Even unplugging and replugging the servo seem to rearm it. Had 3 packs with me, so i hovered all 3. For 2 of the packs so a total of 15-20 mins of hover i had 4 cases of the gyro shutting down. Only on 3rd and final pack could i hover the whole pack without the gyro shutting down. All this made me lose confidence in that the heli is flyworthy. Using the bogstandard DS425 as tailservo is this matters.

Any ideas on why? or is it as simple as a faulty Gyro? Had the Gyro not arm when plugging in the battery on 2 occasions in like 30ish flights but never had it shutdown inflight.

[MattD7]

That to me sounds like it might be a low voltage cutoff. The LVC will give a warning, I believe a tail wag and reduced power and once it hits another voltage shuts off power completely. If you give it the gas during at low voltage you could drop the voltage of the pack below the cutoff voltage.

Were you getting 15-20 minutes out of 2 packs are all three? The longest flight I get out of a pack is 4.5-5 minutes of hovering. Granted that is with the scorpion 2221-6 motor, which is a battery hog.

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Im getting about 7-8 mins per pack for a total of 20ish minutes. Im only using training mode so low power hovering and some back and forth.

Noticed last night that spinning the blades freely there was much resistance, turns out
the bearings in the tailrotor is worn out causing unnecessary friction so i was pondering if
that might put extra strain on the esc to the point where i get unstable power which in turn knocks out the gyro?

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getting 7-8 minutes out of each pack doing mainly hovering and some back and forth flying.
Discovered last night whilst spinning the rotorblades freely that something wasnt right, so i took the tail apart and found that the bearings in there was not good at all making it bit harder to rotate the mainblades around withouth the motor engaged.

So the question is if its possible that the amp draw will be higher on the esc causing unstable current for the electronics since i use the built in bec. Is it possible that this could knock the gyro out? As said before ive never had the Gyro cut out on me mid-air before, only once or twice when plugging in the battery have it not armed but all i had to do was reconnect the battery.. and from what ive read from other ppls posts this aint unnormal?

Or could vibrations cause the gyro to to bananas? bought myself a new training get to get some nose-in hover practice and the legs on it is kinda long so i notice that it sometimes picks up small vibrations from the heli atleast if i touch ground it will pick up vibrations and make the tail shake so i have to land to get the legs settled in and then i can take-off again?

[pinguin]

Did you check the battery voltage afterwards?
It might also a loose wire/solder on the gyro.

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Already recharged the batteries so i forgot to check, flew 3 packs yesterday no problem at all. All ive done was change positions on the bearings in the tail whilst waiting for new ones and not tighten the tail down too hard so that the drivetrain was smoother. Not sure if thats what made it but as said i flew 3 packs yesterday without any problem. Only time will tell i guess