Stripping main gear 2 in one day!!!

[Deano]

I have had this Gohbee 90 for 2 days and have stripped the main gear twice. I am running a OS 90 c spec engine. As far as I can tell you can't adjust them in and I was using the supposedly upgraded gear. How can I fix this?? :arggg: :arggg: :arggg:

[Deano]

Will the Raptor main gears fit on this Gohbee 90?? It seems that if you give the heli quick throttle, it will strip the gears right out. I noticed that the screws that hold the starter shaft casing do slide some but not really enough to even noticed you moved it. Has anyone had this problem??

[WJackson]

A rapor gear will fit i do believe, I think it needs holes drilled to match the gohbee autohub, but that might be inaccurate. Its a direct swap on the 30-50 . Hopefuly Flyinfool or someone whos really familiar with the 90 will chime in.

[kjfaulkjr]

I have a Stinger 50 that is new, that on Friday, just after break in on the engine, I raised the head speed, and we where really throwing the pitch around alot and stripped the main gear. This is the first for me though.
I took the main gear off the Raptor 50 and kept flying.

[WJackson]

Dave is aware of the problem with the main gears on the 30-50. Newer ones are being made after this was supposedly addressed already. The new ones that are not in yet are going to be coming in an air shipment. the rappy gear will solve the problem for the meantime.

[Deano]

The Raptor gear will fit the 30-50 but will the 90 also fit the 90 Stinger??

[flyinfool]

The raptor 90 main gear will not fit the Stinger 90.
The center hole is to small on the raptor gear and the mounting hole pattern is different.
If you have access to a lathe you could modify a raptor gear to work. I did this several times during development before the full range of gears was available.

As far as I can tell you can't adjust them in
The gear mesh IS fully adjustable on the Stinger 90.
I always remove the engine to set the gear mesh just because it is easier to feel the gears. You have to loosen all 8 screws that hold in the start shaft bearing block. I use a big flat screwdriver through the big hole in the side frame, to slide the bearing block forward and back to get the mesh right. The block is a tight fit and does not move easy.
You also want to be sure that the pinion is parallel to the main shaft. It is possible to have the pinion cocked a little and that would cause the teeth to be unevenly loaded.

I do realize that there have been some people that have had issues with stripping gears but in the 1.5 years that I have had a 90, I have not stripped a gear other than when landing inverted.
It was only today that Bill told me that I am not supposed to be landing inverted, I hate when I miss a memo.

I hope that this helps.

[Deano]

I appreciate the help. I'll have to wait to get new gears in (bought extra) to get it all lined out.

[portblock]

I had stripped a couple, and now it seams ok, one thing to check is the height mesh.

Turns out, on my main gear, it would sit higher or lower depending on if I flipped it over or not. So, I flipped it to where it sat the highest, and I also used 6 washers bewteen the one way and the main gear, to add spacing. now my main gear sits better in the pinion.

[Mosco]

One thing to look at is the height of the main gear on the pinion. The pinion has a 45 degree chamfer at the top and bottm, this will allow a bit of bite into the main gear.

On mine, I spaced the main gear higher for a better fit. Also check if you flip the main gear over that it sits higher.

[vanguard]

My first Stinger 50 stripped 3 main gears last year. The last one cost me the entire heli. I bought another Stinger 50 recently and changed the main gear to a Raptor part just in case. There is no adjustment on the 50. Although I thought the mesh looked good to start with on all of the ones I had problems with. Dave was helpful and did give me a couple of gears but it still ended up costing me a heli that really performed well except for that one item.