AnnihilaT

I just converted to the beveled gears for the zoom 400 tail. On the first flight of the day the gear which normally doesnt have problems ( the one which meshes with the motor pinion to drive the tail rotor shaft ) completely stripped within 3 minutes of hovering sending the heli into a wild pirouette (was able to get it down without damage). I figured i might have had the gear mesh too tight and thought that it had to be some kind of fluke so i threw on a replacement and took it up again only this time a bit lower. Same thing happened again. Once on the ground i noticed that this time the gear itself was toasted again but not only that. Also the tail drive shaft itself had broken where it connects to the gear which meets the motor pinion. The shaft at that end is ground down to a hexagon shape to fit the inside of the gear and therefor is less strong at that point. Its precisely at this point of the shaft where it has broken. Looks like the torque simply twisted that part of the shaft right off. Its left hanging there by strands of carbon fiber or whatever.

Anyone had similar problems before? It seems to me i only hear of ppl having problems with the OTHER end of the tail rotor gearing.

I know these tail gears are poorly designed but 3-5 minutes of flight is not right and something else must be wrong here besides just poor design.

Anyone have an idea?

heloman25

I've been through the shogun tail gear nightmare but I believe that I've finally woke up to better days (thanks to beval gears). You should not be having problems at the tail rotor anymore unless there is a reason (like a good tail strike than either the input or all tail gears go). However, now the tail input gear (at the motor pinion) is the week link, I've stripped it out a couple times since changing to beval gears but each time there was a good reason. I've also had a few landings where I thought the input gear would be stripped for sure but found no damage, with beval gears it now seems to be adaquete . Here are some things to check: make sure the tail boom bearings (on both ends) are flush with the ends of tail boom so if there is any slop in the gear clearence it can't bounce the shaft for and aft. Morover, is the crown gear at the motor pinion contacting at 2 pionts (top and bottom),I once stripped an input gear pretty fast with that problem and broke off the end of the drive shaft. Also, do not ever try the alum gears they suck(will eat the motor pinion) and the blue gear witht the set screw does not have enough matirial to hold the set screw (and you dont need it anyway)...beval tail gears work the best, I've had the best luck with all regular (beval) nylon gears.

AnnihilaT

Thanks helo... all good info to have

ChopperMike

Hey heloman25, how's the weather down south (everything's relative, I'm up here in central WI). What bevel gears are you using? I've seen several posts relating to bevel gears for the Shogun, right now I'm using the stock gears. Thanks


Mike

*Crash*Johnson*

My Feedback: (7)

I contacted the people at Hobby People (www.hobbypeople.net) since they are the distributor of the heli. They sent the request over to Global and Global sent me an email and took care of the problem.

The original gears (90* from each other) were a bad design, and the new heli's are shipping with the 45* bevel gears. If ya have issues shoot Hobby people an email and they should take care of ya!
I can take pic's of the old and new gears for ya if ya need.