One-Way bearing problems

[marcosp]

Ok, I might as well open a thread about this problem since I've had my second one-way bearing torn to pieces last weekend. This time at least I managed to land safely.

I am wondering what's going on with my one-ways, I replaced the first one with the whole metal part, not just the one-way. I checked that it was properly greased, and I tried to fly a little more gently. As I found out later the one-way started slipping, the motor turning faster to maintain head speed, and finally I had a thermal shutdown because of the extra power being used. I autoed and as soon as I landed I checked the one-way and it made a crack instantly, almost with no pressure from my part.

I am using the Scorpion 4020-1390, Castle HV110 (my HV85 was killed in the first crash, I mean like transistors falling apart killed), and 35C/40C 5000ma batts. Had a plastic main gear loose a teeth and am using the delrin gear now. Oh, and FBL Skookum unit, guys at the club say it has a lot to do with how I am pushing the heli past it's limit. I am no 3D expert and I consider my flight style though fast and with hard turns should not be so demanding so I am really worried how the machine will stand the rigors of harder 3D. I know people kick the sh** out of this heli so I am wondering what's going on.

So: Has anyone had recurring trouble with one-ways breaking?

I heard in another thread this bearing is identical to the Align one on the 600? I am trying that next.

Marcos

[LITHIUMSTATIC]

That's pretty crazy stuff.... I'm running 8s and pitch pump the hell out of mine without a problem. I do know I'm on the first one-way from the second batch of kits. In other words it's been abused a long time. I'd like to know why yours is doing this. Are you using a light oil in the one-way or thick grease?

[marcosp]

The first one I was in doubt if I had to grease or oil it prior to assembly. In the forums they told me it came oiles from factory which I confirmed on the replacement bearing, and used it as it came out of the bag. Now I am doubting if that oil is good for use or only to prevent rusting. I have both a medium grease like the one that comes for thrust bearings on blade holders, and a light bearing oil. Do you recommend I use one of those?

[LITHIUMSTATIC]

Use grease that's thick enough to not be thrown out, BUT not so thick it keeps the needles from moving freely in the bearing. Usually thin or medium is fine. I use a medium grease I found at my Auto Parts Store. Some cheap stuff. Tri-Flow oil is great!

[marcosp]

I am replacing with an Align 600 owb and will be trying out this weekend. I do not have Tri-Flow here in Argentina, we usually have to guess what replacement product to use that is equivalent. I'll use the medium grease that I use for thrust bearings, it's light enough I think. Thanks!

[DominicD]

I wouldn't use any grease, just flush it out and leave it bare.

[marcosp]

Bold suggestion but I'll take it. The Align owb comes pretty dry.

[DominicD]

The bearing doesnt really move much, just a few times a flight. Its not like a radial bearing that does a few thousand RPM during the flight. The OWB has been flawless on the 550 by all reports, this is why the problem you have is alittle confusing. The only thing i could think of is you are using a stiff grease, which doesnt allow the teeth on the OWB to move properly. Personally i always flush my OWB bearings out from the junk they always arrive with. I then either leave it or flood it with triflow. Triflow is really just a light machine oil with small teflon particals, nothing fancy.

[LITHIUMSTATIC]

I agree with HFG but Tri-Flow makes heavy grease too. I have it and the Tri-Flow oil. I wouldn't do dry... Just don't get confused and reach for the Astro-Glide!

[DominicD]

I use the triflow grease on my thrust bearings, i think its rather on the heavy side for the OWB.

[LITHIUMSTATIC]

I use the triflow grease on my thrust bearings, i think its rather on the heavy side for the OWB.

It is and I'm not suggesting to use it on the own.

[marcosp]

I installed an Align 600 one-way, which is by all accounts identical, same code number as the Outrage one. However it fits loose in the bearing holder so I had to use loctite for bearings to lock it in. This is regarding the contact of the bearing with the aluminum piece it's held in. On the inside, where the shaft sleeve goes, I cleaned the grease it came with with alcohol and put just a tad of bearing oil, one I've had for years branded Trinity, like the buggy motors. First flight (one minute and a loop later...) the bearing came loose in it's fitting. I pulled it out, cleaned the whole thing and started over Saturday night. This time I scraped the inside of the bearing holder and the outer surface of the bearing (quite hard since it's steel) so that the loctite would grip better. After a whole night of drying I put small drops of cyano glue all around the joint. Today I put 6 flights on the heli, from scared to use full collective to "almost" as hard as I can push it, fast turns, tic-tocs, etc, at all times doing the most collective management I have done ever. 2100 rpm on the first 2, 2250 on the last 3. Still not flying it unconcerned and pushing it to its limit.
A fellow pilot also recommended I loosen the tail belt a tad. His theory is too much pressure can make the bearing work unevenly and heat up and/or fail. I disagree, there are too many bearings around that area for the belt pressure to have any effect. I loosened it a bit anyway, paying attention to well known tail belt tension precautions. I don't know if the success so far has anything to do with the belt tension, the new brand owb or the lighter oil. For now, it seems to have been solved. I just hope it lasts and would have really liked to not have dealt with all of this. Cheers! Marcos

[marcosp]

I've been mulling the las couple of days if the owb breakage can be caused by a too aggressive governor on the CC. I use medium setting on 3.20 firmware. It's like 15 and many people mention prior to the update the medium sensitivity was around 5 to 8. I never questioned before that the medium setting might harm the system, but I am doubting now. Will try the low setting next weekend and see if it holds rpm well enough I'll leave it there.

[wolfdown]

There was a video posted by CC about this recently. As long as you don't hear chatter between the pinion and main gear, then its probably low enough. I have mine at 30 and the CC rep said he was using 25.