Overspeed problem?

[TomCarey]

Good afternoon all.

My first post on here so go easy on me, my technical knowledge is not that great!


Basically i have 2 trex 700n both with 105 hzr and both with 7300bx one runs hv servos the other are standard
the problem is the model with the standard servos when putting load on is fine but coming off load i get like
a drop with the heli like it will drop down to one side when coming off load. If its on load off load like a tick tock its ok
just the problem stated above. I know its a bit vague.. some have said putting more padding under the beast x, when it does
drop down with no load on it, its uncontrolable for 1-2 seconds which make for a squeeky bum moment.

anyone experienced this or could provide an insight?
Would be much appreciated for a cure



thanks

[Boggy]

Welcome to the forum Tom.

[waveydavey]

Welcome Tom, I'd suspect bearings and vibration. I wouldn't put more padding under the BeastX it will make it worse. I'd suspect the clutch stack, the bearings take a hammering on the 700n, either those or the mainsaft ones top and bottom. When was the last time these were changed

[trillian]

Sounds like the usual BeastX vibration thing. When it gets a certain amount / frequency vibration it will do an uncommanded roll. I had a Beast X on a Trex 500 and it would be fine and then when I flipped to idle-1 it would suddenly try to roll hard to the right and It took full left stick to regain control, then it would be fine for a while. The solution in this case was to actually mount it more firmly so I added a strap over the top and this cured the problem imediately.

[TomCarey]

Its just had new main shaft, feathering shaft and dampners in head...

[TomCarey]

Sounds like the usual BeastX vibration thing. When it gets a certain amount / frequency vibration it will do an uncommanded roll. I had a Beast X on a Trex 500 and it would be fine and then when I flipped to idle-1 it would suddenly try to roll hard to the right and It took full left stick to regain control, then it would be fine for a while. The solution in this case was to actually mount it more firmly so I added a strap over the top and this cured the problem imediately.

Its not doing an uncommanded role just flying around its only when head is put under load then off load i get the uncontrolable 1-2 sec wobble / drop which will end up
in curtains

[waveydavey]

It's as Sheryl said vibration, please don't add more foam and find the vibe. My bet is bearings

[electricsceadu]

I wouldn't beleave for a minute
that any align bearing was any good in a 700n
start with changing the clutch stack and mainshaft bearings with a quality bearing
and not with align junk bearings

[brin]

tom flys at my club and from what i know both helis have had the main shafts and bearnings changed and one has had a new clutch and liner and one is a brand new built kit.May be that remounting the ar7300 could cure the issue .Worth a try.

I wouldn't beleave for a minute
that any align bearing was any good in a 700n
start with changing the clutch stack and mainshaft bearings with a quality bearing
and not with align junk bearings

[waveydavey]

Brian the BeastX needs to be hard mounted, 1 layer of Maplins double sided and if it still craps out then theres something seriously out of whack

[trillian]

Where do you have the 7300 mounted Tom? Are they in the same place on both helis? If it's in front then I'd suspect engine vibes, if it's over the boom then it could be tail blades, tail shaft, TT etc. These things can work in mysterious ways, sometimes it can be counter-intuitive.

[brin]

Hi Dave. i have mounted all mine with the 3m equivalent and they seem rock solid although his 700's are nitro and more prone to vibes.Not both have the problem and yet they have been setup the same.I will give Tom some of the 3m tape to try.

[TomCarey]

I have noticed that the mounting pad on the one with the problem is quite a bit thinner than the one without the problem

[electricsceadu]

if its had align bearings fitted they can fail with very few flights on them
has the cltch stack bearings been replaced? is it using the plastic clutch stack? if so are the bearings secure in the plastic
if they are still about the metal clutch stack is a better option

tom flys at my club and from what i know both helis have had the main shafts and bearnings changed and one has had a new clutch and liner and one is a brand new built kit.May be that remounting the ar7300 could cure the issue .Worth a try.

[brin]

thats one for tom to answer.

if its had align bearings fitted they can fail with very few flights on them
has the cltch stack bearings been replaced? is it using the plastic clutch stack? if so are the bearings secure in the plastic
if they are still about the metal clutch stack is a better option