Maiden flight on new 700 piro issue

[Wbird]

I went to maiden my new 700 yesterday and 1/4 tank through, tried some rolls, flips slow rainbows. Everything seemed fine. Went to do a piro to check the piro rate (1st time on spartan gyro) had it in a stationary hover and gave full right rudder, just when I did I heard a snap, almost like plastic breaking, not that loud but could hear it over the heli. I came out of the piro fine, landed and everything looks fine. Gear mesh from tail drive to auto rotation gear looks good, all teeth everywhere are perfect. I have the alum clutch bearing block. Is it possible that the clunk (stock Align) in the tank hit the side of the tank hard enough to be heard? That is all I can come up with.

Any Suggestions before I fly again?
Thanks,
Conway

[lowflyer101]

tail blades farted :YeaBaby:

[Auto180]

tail blades farted :YeaBaby:
:badair::badair::badair::whip:whip:dance:dance:woo t

[Ludde]

Id say check that the bom didnt slip.. this gives a sound like that..
or TT gear going to stripp

[stevehonn]

I used to get a similar sound on fast stops, definitely something in the tail gear train although there's no sign of damage. I've turned down the acceleration & deceleration on the Spartan gyro using the USB link, if you leave it set to the default of 100% then there's a chance of stripping a gear.

[GenReaper]

Fuel Block off may have hit the side frame.

Do you have an alloy plug in your fill line?

[Tom Burgess]

I would say there is almost enough backlash in the TT gears to skip a tooth ;)

[Wbird]

tail blades farted :YeaBaby:

I wish it were so, LOL Good one! Could just leave it alone and keep flying.

Thanks for all the input guys, How should the backlash be set on the TT gears? Everything looks fine to me but I will definitely go over it again. Is there a way to adjust or should I get some shims made for somewhere?

Fuel tubing and Filter, etc is all stock except a plastic pinch valve next to the carb.
Spartan is set to 80% on acceleration and deceleration, what should I set it to, BLS251 servo What spacing on servo horn? The sound I heard was at the start of the piro, not the end.

Thanks again,
Conway

[Wa11banger]

Tommy and Troy discovered the same problem when doing hard maneuvers. The solution was to remove the boom support/horizontal fin mount and put crosshatch score lines in it and lightly sand the shine off the boom where the two meet.. The noise went away so more than likely that small crack noise you here is the boom flexing enough to slightly slip the boom support mount. I took the half way route I just scored the clamp and did not sand the boom. I do not have enough flight times to state if this was adequate enough or not.

Rick

[j2m]

Interesting thread! I recently completed a second 700N fitted with a Spartan gyro and I have the same issue. If I stop rapidly from a left hand piro I get a sort of "braap" noise for a fraction of a second while the tail is coming to a stop. I checked the mesh on the front and rear tail gears and couldn't see any obvious problems. The mesh seemed only slightly looser than my first 700 (which doesn't have the issue) and there's no damage to the gear teeth. I have tried reducing the stop gain from 100% to 655 and this seems to help but I can still create the noise if I'm hard on the stick.

It really sounds like gear teeth somehwere in the drive train are skipping under load. I have tried holding the main rotor head and trying to force the tail around with my other hand. When I applied a lot of torque i got a really loud series of clicks and the tail moved around a 1/4 turn so something is definitely giving under heavy load. The really odd thing is that there is still no sign of any damage to the tips of the gear teeth

[lowflyer101]

BTW, there r little play on tube shaft and innner front / rear tube gear, it could cause sound also.