one way bearing

[liam-b]

i need to replace the 2 bearings that go above and below the one way i forgot to check them when i ordered all my parts as i can hear a noise when its spinning like theres abit of dirt in there so how do i get the one way out is it a case of putting it in the oven as i dont want to ruin the existing one way as i think its fine

but in the parts manual the one way part number is 63-61245 but that comes up as thrust bearings on the online store :S and i am unsure of the part number of the lower bearing is it 60-15245 and then the bigger one at the top but i carnt seem to find what that one is :S does any one know
thanks liam

[Rob43]

The assembly has the one-way hub spinning inside the bore of the plastic main gear when autorotation or spooling down. I bet this is the noise you hear. At least check it before bothering with the bearings. I have found it to be a tight clearance. As in, if cold, it's got no clearance. It's much better if lubricated and warm. Just a thought.


Rob

[liam-b]

Originally Posted by Rob43

The assembly has the one-way hub spinning inside the bore of the plastic main gear when autorotation or spooling down. I bet this is the noise you hear. At least check it before bothering with the bearings. I have found it to be a tight clearance. As in, if cold, it's got no clearance. It's much better if lubricated and warm. Just a thought.


Rob

it was while i was rebuilding it and i could hear like a clicking sound it so i took the bottom bearing out and i could feel something when it span round its not notchy but i can feel it it does it once for nearly every full turn

[Rob43]

Was it damaged in your mishap?

[liam-b]

yeh i dint think to check it before so just need to find the part numbers now and should be all good

[njs77]

Originally Posted by liam-b

it was while i was rebuilding it and i could hear like a clicking sound it so i took the bottom bearing out and i could feel something when it span round its not notchy but i can feel it it does it once for nearly every full turn

Did you solve this issue? What parts did you have to replace? I'm having same clicking sound from main gear assembly..

[liam-b]

Yeh all I had to do was replace the bearing above the oneway and the one below it.
Bering Hub.
But note they are both different sizes the top one is bigger and the one below al try get the part numbers when I get home

[alexmit]

I have had 2 one way bearings in my 7HV. Both either squeaked or make some sort of scrape noise. I just thought it was normal. Is everyone else's one way silent?

[heathy]

When i walk over to my heli as it spools down i can hear a click, maybe the same problem?? I'm not too bothered at the moment though as it spins very freely and has been recently lubed up.

[liam-b]

Mine spun freely aswell if I remember rightly. The sound just annoyed me. And dint p want it to make a vibe. So did it while it was appart All it turned out to be was them2 breaings clicking once per rotation

[heathy]

Next time i crash i will be sure to replace them, usually not long

[liam-b]

Ahha av only flown mine twice after that crash dropped my lipo and t split and have not been able to afford another set or it. Wanted to take it down to air at Weston park for the fun fly =[

[Rob43]

I have been learning about lubrication from a specialist at Molykote (Dow Corning, owned by my company, The Dow Chemical Company). He tells me he has an ideal formulation for our special metal to plastic points, such as one way hub to main pulley (I was inaccurate saying the hub spins in side the main gear - it's really inside the pulley since the main gear stops and the pulley keeps rotating). A solid plate lubricant will be perhaps better here. Not a big deal without, but I like how quiet mine is compared to others with whom I've flown. Once I learn of the product that Molykote recommends, I will share the details. It will be used for main gear to pinion mesh, and for one-way hub to pulley contact.

[heathy]

Originally Posted by liam-b

Ahha av only flown mine twice after that crash dropped my lipo and t split and have not been able to afford another set or it. Wanted to take it down to air at Weston park for the fun fly =[

Liam, what day are you going to "Air"?? I'm going on the sat

[alexmit]

Originally Posted by Rob43

I have been learning about lubrication from a specialist at Molykote (Dow Corning, owned by my company, The Dow Chemical Company). He tells me he has an ideal formulation for our special metal to plastic points, such as one way hub to main pulley (I was inaccurate saying the hub spins in side the main gear - it's really inside the pulley since the main gear stops and the pulley keeps rotating). A solid plate lubricant will be perhaps better here. Not a big deal without, but I like how quiet mine is compared to others with whom I've flown. Once I learn of the product that Molykote recommends, I will share the details. It will be used for main gear to pinion mesh, and for one-way hub to pulley contact.

I'm a little confused. There are no metal to plastic parts rotating in the gear train that require lube except maybe the pinion to the main gear. The bearings are metal to metal and that is what is rotating. Have I missed something?

[liam-b]

Am goin sat aswell. =p. al take it down just in case see if I can borrow a pack or too =p.
Taking the velocity aswell so at least I can fly one =D mite see you down there

[EricW]

Originally Posted by alexmit

I'm a little confused. There are no metal to plastic parts rotating in the gear train that require lube except maybe the pinion to the main gear. The bearings are metal to metal and that is what is rotating. Have I missed something?

No, your right.
The oneway is metal to metal, and in locked position (95% of the cycle time) you prefer to have maximum grip.
You need a little lubricating for the freewheeling and mostly corrosion protection of the oneway "bearing".
Grease is not recommended in most cases, causes slip and stick.
I really never understood why they call it a "bearing" anyway.

[njs77]

Originally Posted by liam-b

Yeh all I had to do was replace the bearing above the oneway and the one below it.
Bering Hub.
But note they are both different sizes the top one is bigger and the one below al try get the part numbers when I get home

Weird, because in part list there's same number for both bearings, 60-15245
http://www.rc711.com/shop/documents/...v-partlist.pdf

But let me know the part numbers and I will order those. Thanks.

[Rob43]

Originally Posted by EricW

No, your right.
The oneway is metal to metal, and in locked position (95% of the cycle time) you prefer to have maximum grip.
You need a little lubricating for the freewheeling and mostly corrosion protection of the oneway "bearing".
Grease is not recommended in most cases, causes slip and stick.
I really never understood why they call it a "bearing" anyway.

You have both missed the friction point I am referring to. Look at the parts list for 7HV. Friction is between p/n's 05-0602 (one way hub), and 09-7026 (main pulley). When freewheeling during spool down, or autorotation, the pulley is rotating on a now stationary one way hub. I couldn't understand why my one way is so tight. Lots of friction. I had it out many times since the build a year ago. Last summer when I ate three main gears it was out a lot. That is wheyn I disovered if the pulley if removed, the one way assembly is extremely friction free. Put it back on, and it's tight. Maybe, in my case, the pulley is tighter than yours. There is zero clearance in mine. Since noting tight one-way assemblies is very common in the 7HV owners, I assumed it's true for all. I just don't quite understand why this fit needs to be so tight. Upper and lower portions of the drive assembly are carried by roller bearings. The pulley is piloted to it's own hub, p/n 09-7070, which, in turn, is a precision fit to the one way sleeve, it could be that Sebastian thinks he needs this snug fit when freewheeling due to the belt load on the pulley. I don't know for sure. I will say this, unless the clearance of the pulley to the oneway hub has been increased since the first batch, you will find this to be a friction loss in auto rotation. Simple as that.

I don't grease my one way roller either. I think it needs some light oil to help prevent corrosion, and brinelling, but I agree about that.

[GimpyGolden]

Rob,
Did you ever come up with a solution to free it up some?
I still have #2 on the bench, I may tear the main gear/pulley down to have a look.