White Front bevel gear complete lose in flight

[omerco]

recently I have changed my tail servo to MKS X8 HBL880. its a very strong and fast one goes up to 11kg. tail behavior is superb - the tail just never gives up.
but a few weeks ago I started to have some weird noises. after some elimination I found that the front bevel was worn (it was roughly 1.5 years old). I replaced both the main crown and the bevel.

and than... well look what happened to me a week ago:




it looks like it just melted...miraculously I managed to save the bird

But now I wonder - I did find some worn bearings in the torque tube/ tail mechanics. that might had put some stress on the bevel but nothing was too dramatic. replaced all of them.

Another reason might be the meshing was wrong. I would be happy to hear some advises here. I do set it up tight since the days of the black ones. maybe too tight?

Or maybe it is just not up to the stress with new strong motor and tail servo?

omer

P.S
Setup is:
Xnove 4530 525kv. 60c batteries. scorpion 160HV
governed by Skookum governor to 2100 rpm with 713 main blades. hard 3D.

[lucidchaos]

I am interested in hearing the result as I am rebuilding mine with the same motor and ESC. My servos are Xpert R2's so also very strong. I replaced all gears with the white versions.

Haven't gotten it airborne yet with the new parts but that's probably coming in the next couple of weeks. Seeing as I am decking it out with the Formula canopy and CF boom, I don't want to take unnecessary risks from a financial standpoint...

[omerco]

for now I have reset both my X7s with a minimal mesh. I did find out something interesting:
I have one x7 with formula head and another with "old" head. The main shaft is just a little bit nerrower on the formula. When assembling I found out the OWB hub - the one the big crown gear is screwed to - has different sizes: one fits the regular and one is nerrower and fits only the formula.

When my crown gear died I had the regular one in the formula, which gives more slack because it can " play" on the shaft and might change the mesh. Although it's minimal.

I didn't have a chance to test fly the formula with the X8 tail servo yet though.

[victor gomez07]

To me I had worn that gear 2 times until I corrected the washers that go from the top of the main gear only leave the thickest and so far everything well also ran the tail pipe to the maximum that gives to fit well lso gears

[omerco]

The thing is that my mesh was tight with this one, and it was almost new. I still don't have a good explanation for it. I now have a black crown which is more brittle but harder, with zero mesh. Hope it will hold.

[DanMcN]

I'm not sure what thickness my washer is above the main gear but I'm real close to the main gear hitting the frame. Still seams like a lot of gear lash.

I get a lot of white gear dust.

[omerco]

That's off topic, but you can add washers between the OWB assembly and the hub (the part with the flat big crown gear) and lower the main gear by that.
Dust usually comes from the pinion - main gear area.