ONE WAY BEARING FAILURES

[fusionsx00]

Its a touchy subject to a gaui vendore, at the local hobby shop I go to
I mention this, and they say they never have problems. Now I hear they
do think the owb are junk, and the newer ones are better.
and now I hear the newer ones gaui is using are not reliable either
I met a guy that had his gaui built there and 2 new stlye owb went out in under 3 flights
.
I been fighting this problem too, 3 owb. And other bearings failing too one day one thing next day
another, it could be bearings back out of there blocks, or owb going bad, no way to tell.
I don't know what to think
im not buying gaui owb anymore, they only come with the gear
so im giving vxb one more try, and boca is next

I don't know if I am to blame, I went a ton of flights no problems
I have flight logs to back it up, and I have no reason to bash the only brand heli I fly
besides th mcpx, if gaui made a ultra micro I would have it

[hfenn]

Got my VBX bearings in the mail this morning and when I was pressing the old bearing out of the gear, I found the gear had cracked between a couple of the teeth. I put the VBX in with some green loctite and will clamp it together with light pressure for a few hours before trying it. When I ordered the bearings from VBX, I also placed an order with Heli Flight Center for a new gear and one-way shaft in anticipation of some other problem. That order is due here Saturday, so if the loctite fix doesn't hold, maybe I'll get my bird ready to fly early next week.

[Stoats]

Originally Posted by hfenn

Got my VBX bearings in the mail this morning and when I was pressing the old bearing out of the gear, I found the gear had cracked between a couple of the teeth. I put the VBX in with some green loctite and will clamp it together with light pressure for a few hours before trying it. When I ordered the bearings from VBX, I also placed an order with Heli Flight Center for a new gear and one-way shaft in anticipation of some other problem. That order is due here Saturday, so if the loctite fix doesn't hold, maybe I'll get my bird ready to fly early next week.

If it is cracked at all, throw it away immediately! Saving $10 now will result in a crash and then you'll need to buy a new OWB anyways. The loctite will not hold the pinion together and keep the OWB from spinning inside it given the forces it experiences in flight. Also, the OWB pinion probably won't mesh as well with the 61T main gear which will cause premature wear and vibrations.

On my original 550, I stripped a few 61T gears which apparently cause the OWB pinion to crack. Within a flight or two, the OWB started spinning inside the pinion causing the heli to lose power from about 30ft up ... that was all she wrote for the plastic hurricane.

[hfenn]

Thanks for the heads up!

[sp00fman]

beenflying, thanks for the e-bay link for thew VXB one way bearing. I ordered one this evening, one hour later got a message it was shipped
Its just for backup. my stock OWB seems to hold the initial test flights.


The other OWB (abec3) seems to have a smaller amount of roller needles, judging from the picture. My gut tells me more = better, but who knows

[beenflying]

Originally Posted by sp00fman

beenflying, thanks for the e-bay link for thew VXB one way bearing. I ordered one this evening, one hour later got a message it was shipped
Its just for backup. my stock OWB seems to hold the initial test flights.

You're welcome. I'd still suggest you replace it, unless you're good at auto landings. I think our kits came from the same HK batch.

The other OWB (abec3) seems to have a smaller amount of roller needles, judging from the picture. My gut tells me more = better, but who knows

The picture is another size bearing (HF1012), and I'm not sure if the VXB picture shown is the correct bearing either. I'll let everyone know when they arrive.

I'm guessing the problem with the kit OWB is the roller springs are too light. Possibly not hardened enough. Centrifugal force is pushing the rollers back from the locked position.

[fusionsx00]

I just got my vxb owb, and they don't "coast"
I read that they should coast when you flick them on the shaft.

Hmm???

They are smooth, I haven't installed them on the gear, but there not a press fit anyways
so are these bad?

I asked for help today at the hobby shop, the guy gave me a go f ur self look and then ignored me after he said he would help me??

Its gona be hard but im not going back to that store period, this was the store manager
he flys helis, and the other employee that did do his best to help me, was not a heli guy
so his help was limited, he did help as much as he could.

I don't know what I did wrong, I spent 350 there last month, over 1500$ last year
guess he doesn't need my business

[beenflying]

No offense to nexgen, but I'd be amazed if a OWB would coast without a big flywheel.

I ordered the ABEC 3 OWB because of the issue with the VXB OWB not being a press fit, but others appear to be having no issues with the VXB part thread locked in. The Align 250 relies on the pinion being held with thread lock only (no set screw). Even though the torque would be higher with the 425, the thread locked area is much larger.

[hfenn]

I agree that the owb won't coast, but should feel smooth and free in the unlocked direction. The VBX feels much better in that regard than the Gaui owb did. It sucks that my gear cracked and I'm now waiting on a new one to get going again. BTW, you don't want to use thread lock in this application, but rather sleeve retainer. This is what I'll use:
http://www.permatex.com/products/aut...e_Retainer.htm

[spootman]

I'll agree with the others, never had a OWB that would coast on its own. My VXB bearing was not as tight as a fit as the original Gaui bearing but still needed to be pressed in. I used green loctite on it. I put the loctite on the outside of the bearing with a toothpick and then pressed it in, I then wiped off any excess to make sure none got into the bearing. It has been good ever since (about a year maybe).

[gpraceman]

Are these OWB issues with the CF frames only or does it also affect those with plastic frames? I have yet to fly my 425, as I am finishing my build up, but after reading several threads about OWB issues I am a bit nervous to fly it now.

[beenflying]

Plastic frames, in my case.

[fusionsx00]

I have green loctite on the way
Thanks for the heads up

No telling maybee we need a poll?

Lube or no lube
vxb or boca or stock
plastic or cf frame
How many flights before a failure

[gpraceman]

Originally Posted by fusionsx00

No telling maybee we need a poll?

Lube or no lube
vxb or boca or stock
plastic or cf frame
How many flights before a failure

Maybe so. I wonder if there is any commonality in these failures.

[KRYPTO316]

Plastic frame here.

[Brick]

i know Gaui has a funky gear ratio system, i wonder has anyone looked for a compatable main gear/owb from another heli source?

[fusionsx00]

Well that makes sense, the 550 guys have a lower kv motor
and there first stage is spinning way slower

My conclusion is the owb cant handle 425 high rpms
1400 kv vs 960? Or close to that

My calculation is a 425. 1400 kv motor the owb shaft is at 8441 rpm
Vs a 550 on a 960kv the shaft is spinning 5700 rpm
close to 3000 rpm diffrence

Im not saying that's it, but I don't see that many posts of 550 owb failures

The gaui owb are no good period, the vxb should be lasting a while

I wish a gaui rep or distributor could help us out, I get the feeling that we are on our own
here,

[fusionsx00]

I was just thinking that it would be cool if I lived close to a hobby store
that sold gaui, and that had team pilots working there, and at one store they have a manager that inspected the first x5 helis that went out to the team pilots and has extensive helicopter knowledge ,
yeah that would be nice, oh wait I do, and yet im here getting help which I greatly appreciate from fellow helifreaks, instead of the support I should be getting from the place I bought my 425 kit from, or 90% of my parts
come to think of it I kinda remember being told I would have experts able to help me with any problem I have.

If it wasn't for this website I would of done sold all my gauis

[papa38]

Is the gear that the OWB is in plastic or metal? Loctite should not be used on plastic as it will break it down.

[fusionsx00]

The gear is metal, the vxb owb has delrin or similar inside
But it has a metal housing

So its metal on metal

The main gear is plastic, owb gear metal

I'm looking at diffrent gears, but my first stage shaft is still at
7500 rpm, I'm gona email vxb and see what they think the max rpm of the owb is