Logo 700 14t pinion failed

My 14t pinion separated today and stripped my main gear. Luckily there is no other damage.

Hi Ben,

I just saw your RMA and answered accordingly. Quickest way to get you going again would be to contact your dealer for a replacement of the damaged parts, then we can settle things with them afterwards.

Kind regards

Eddi

Born to fly ...
forced to work.

Hi guys. Just noticed this. ( please see pics bellow) Should i be concern? Done only around 20 starts with new Logo 700.
Can’t remember whether the slight shift of the herringbone has alway been there since new on whether the pinion is going to fail. I’m NOT a smack down hard core flyer. So no huge stresses on the gear.
Thank you for your thoughts.
R



Edited 2 time(s). Last edit at 07/12/2020 06:31PM by Radek.

Hi Radio,

in my opinion, all looks well. The pinion consists of two helical-cut half-pinions, one slides onto a sleeve of the other, and is a press fit secured with laser welding. At the tip of the V, there can be a tiny bit of an offset or shift, so the plastic main gear will wear in a bit, and this is what you see.

The issue above you see if the laser welding fails. This happened a couple of times, with one of the original batches of pinions manufactured and sold back in 2017. Problem is, you can't see inside, in QC, if the weld looks good you must assume it's good.

Basically, if you would mount the herring bone gears with an axial offset, they would also try to center, with the forces in play. This could cause the main gear to warp ever so slightly, causing extra wear, and possibly put strain on the pinion as well as the motor shaft and bearings, if there was no axial play on the bell to compensate for slight offsets.

I'd eyeball it every flight, to see if it becomes any worse.

Kind regards

Eddi

Born to fly ...
forced to work.

Hi Eddi
Many thanks for your response . I think exactly the same. I just had quite a long break between building the heli and properly flying it. So that’s why i can’t recall the exact look of the pinion while fitting it. I don’t mind little marking on the big wheel. The wheel always adjust itself against the pinion in time anyway. I’m watching it after every flight but it’s not getting any worse. So i hope it’ll be fine. I’m aware that the splitting issue is relatively old just wanted some little assurance
Thank you Eddi, what would we all do without you

Radek



Edited 2 time(s). Last edit at 07/13/2020 11:27PM by Radek.