Rave 90 E tail gears stripped on spool up :(

[TonyUK]

Hey guys, the maiden of my Rave 90 e went ok, nothing perculiar. 2nd flight came and i spooled up and whizz pop bang, both the gears in the tail case stripped, fortunately it was still on the ground so no damage apart from the offending items.
Just wondered if anyone else has had this problem? There doesnt seem to be any way of setting backlash, its just fit it and its done. It did over rev somewhat before it settled at my 2000 rpm but i dont see why higher head speeds would strip them, ive had my 700e at 2300 and no issues.

Any thoughts appreciated!!!!

[rachel]

is this an ENV or a ballistic ???
I have heard of front gear stripping but thats usually poor frame alignment.

No way the tail blades were over center ?

I really load the tail on my 90 ENV nitro and to date its been bulit proof (touch wood)

X Rachel

[TonyUK]

Hi Rachel, this is the ENV, i bought it 2nd hand over christmas and LOVE how it goes together, especially from a maintenance perspectivem how the bearing blocks pop out so easy, motor etc. Not sure what you mean by over center, do you mean servo centred and pitch slider central?? if so then they were centred. Bit of a head scratcher this one.

[rachel]

Hi Rachel, this is the ENV, i bought it 2nd hand over christmas and LOVE how it goes together, especially from a maintenance perspectivem how the bearing blocks pop out so easy, motor etc. Not sure what you mean by over center, do you mean servo centred and pitch slider central?? if so then they were centred. Bit of a head scratcher this one.

yes thats what I ment,....... I have quite a lot of experiance on the env but its a new one on me.

SH as in flown ???? maybe previous damage ???

as you said no adjustment and the tail gearbox is a work of art so rebuild and just be carefull on the spool up.

Rachel.

[TonyUK]

I'm guessing it was flown, and the only explanation I can. Think of is to prior damage, I agree, rebuild and take it easy.
cheers Rachel.

[jayfrs]

Dude was a lucky one today, it most prob might have been damage before because it looked like a 3 year old dolphin had put it together untill you got your hands on it!! all about next sunday

[TonyUK]

I know mate, just can't believe it held out during the first flight. Not the best days flying, but here's to next weekend.

[steve_b]

I've not seen this problem either and I've got both an electric and nitro ENV.

One thing I have had recently is the torque tube failed in flight on my nitro ENV, where the securing bolt fits through the tube and the splined end, so while you've got the tail gearbox off then it may be worth checking that and replacing if necessary.

[TonyUK]

Have you ever tried a trex 700 torque tube, I've had the raves and the align tt side by side and they look identical.

[steve_b]

I haven't tried the 700 TT as I had a spare ENV TT from an earlier crash so I just used that.

[RSeeG]

Flying buddy of mine had a similar problem with his Rave ENV. Plastic tail gears melted during maiden. Found out that you need to use a reasonable amount of force to press the inserts into each end of the boom. If there is no backlash, they arent in enough.

[TonyUK]

I have a bit of a theory why this happened. the throw on one way (pitch slider all the way right) was so extreme that the tail blades almost flatten out acting almost like an air brake, so the head wanted to do 2000rpm and the tail on spool up wanted to slow them down. worse at spool up because of motor torque and gyro correction.
my theory anyway. I've adjusted the throw limits so ill see what happens at the weekend.

[steve_b]

Not sure about that theory to be honest, I've got both of my Raves set to use the full travel and as you say when the slider is across to the right then the pitch on the blades is quite high. But in over 200 flights on one of the helis and 50 on the other the tail gearbox gears still look fine.

As RSeeG suggested I'd look at the mesh between the gears as if that's too tight then it would cause problems.