metal main bearing block question

[bobbybe]

hey all,
so i've blown out both of the bearings above and below my owb again... i think they lasted about 20 flights or so (god i can't wait for the hh frames). i was taking it apart, and i'm wondering, on the main bearing block, do the flanged parts of the bearing holes point up or down? i had them pointing up but now that i've gone through yet another set of bearings, i'm wondering if i should flip it around and have the flanged part on the bottom.... lemme know what y'all think

[mysticmead]

mine is pointing up I believe...

[bobbybe]

so the narrow part is at the top?

[mysticmead]

no.. narrow side down... at least it looks like that.. but without removing stuff it's hard to tell..

[mjdee14]

The bearings blocks should be so BOTH lower and middle (bearing just above OW) can be inserted from the center.....

So bottom block flange is down......middle block flange is up

The OWB and washer is suppossed to keep both bearings in their blocks.

You can secure them with locktite or peen them in....

[bobbybe]

thanks guys. now i have another problem trying to put it back together...
you know that really wide washer that goes right underneath the front main gear? it seems that it is so long that it will actually push the owb bearing (the one on top) about 1-2mm so that the bottom of the bearing is hanging down below the main bearing block.... i've tried a coulple diff configs but it seems like it's always pusing that bearing down becaue the washer is to wide... what should i do about that?? thanks

[mjdee14]

Go back to using two washers...one above and one below your one way gear.

The purpose of using one was it was originally too tight....if you have that much room you can probably get away with using both.....

You can also locktite or peen the bearing in place(peen, using a small punch to dimple the aluminum holder around the bearing race) so they won't move....

If you bearing is hanging down....it will most like rotate the outer case and wear it faster.


When everything is spaced properly...that wide aluminum spacer can't push the bearing down...that is if you have both the bearing blocks in properly and washers in place.

[bobbybe]

thanks mike... i have my owb in so that the side with the slightly raised edge is facing up... i think that's the right way but it's hard for me to figure out when the rest of the gears aren't on
however, there's no extra space at all- i can't wiggle the gear or owb up and down at all. it seems like there isn't enough room below the front main gear hub so when i put it in, it pushes that extra wide washer down into the top of the main bearing block, pushing the bearing itself down

edit- i just took the whole owb and bottom bearing block out to see if the top bearing would be pushed in if i set the main gear in the middle of the slot of the cf frame. it seems that if i push the top bearing all the way in, the front main gear rubs abainst the top of the cf slot, but once i push it down to where it's supposed to be... that really wide washer thing (that goes in between the main gear and the upper bearing) will push the bearing down from the block and it'll stick out a bit. it's almost like that big washer is too long. uggggh

[bobbybe]

ok sorry for the extra posting... but now i just put the owb in properly (haha you'd think i'd know by now :p) and all the bearings and screws in (and the extra washer... one above and below the owb now). but, now it seems like the whole owb shaft will move up and down by a mm or so... i can't for the life of my figure out where the movement from the owb shaft is coming from. for example, i can push up on the screw at the very bottom of the owb shaft and i can push the shaft just barely high enough so that the front main gear rubs on the top of the slot.

any ideas??

[kahn10]

bro....have you got the washer on the bottom of the owb shaft on?

[Mikej]

Are the grub screws definitely in the "dimples" in the shaft at the top ???

[mysticmead]

check both the washer on the bottom..and the set screws...then go fly.. as long as the gear isn't rubbing, then it's OK... mine has almost 1mm of play in it

[keepnitflying]

Originally Posted by bobbybe

thanks mike... i have my owb in so that the side with the slightly raised edge is facing up... i think that's the right way but it's hard for me to figure out when the rest of the gears aren't on
however, there's no extra space at all- i can't wiggle the gear or owb up and down at all. it seems like there isn't enough room below the front main gear hub so when i put it in, it pushes that extra wide washer down into the top of the main bearing block, pushing the bearing itself down

edit- i just took the whole owb and bottom bearing block out to see if the top bearing would be pushed in if i set the main gear in the middle of the slot of the cf frame. it seems that if i push the top bearing all the way in, the front main gear rubs abainst the top of the cf slot, but once i push it down to where it's supposed to be... that really wide washer thing (that goes in between the main gear and the upper bearing) will push the bearing down from the block and it'll stick out a bit. it's almost like that big washer is too long. uggggh

The raised edge goes down (may be the prob)

[bobbybe]

mccomb- yeah that's what the post after that was for... realized i had it on upside down and put it in the right way. that helped with the above-owb bearing not being pushed down as much but there's still that up/down play

i did end up putting 2 washers in, both right above and below the owb. i tried with one at the bottom first, but there was too much up/down movement of the shaft so i put in both.

i'm starting to think that i was flying with this kind of up/down play before and it may be a contributing factor to the blow-outs of the upper and bottom bearings

ohyeah... marco- do you mean the one below the owb or the one that goes over the screw? i have both in... i wonder if a wider spacer for the screw would catch on the bottom edge of the bearing block and keep it from moving at all? hmm....

[keepnitflying]

Those bearings are a problem.

C'mon Gaui hows about 2 new bearing blocks with full size bearings.

They added the much needed bearing in the motor mount.
Now I think they need to finish the job.
I know I would be happy to pay for the upgrade.

Gonna rebuild mine today again as well.

[bobbybe]

you know ben is making a new bearing mount with full size bearings for the one above the owb (and below as well!!)
he's including them in the hh frames but i think he's also planning on selling them seperately. i'd definitely get one of those if i wasn't already getting the whole frame

[keepnitflying]

well took mine part, was having a bit of tail jumpin and bearing noise.
had one washer above
one below
My spacers were apparently metal plated (great)
well duh
the plating is coming off
the owb is probably pissed about these bits
The owb is greased? I forget should I grease it again after I flush it?

[bobbybe]

no grease on the gaui owbs at all! it's wierd but true.

ok so im an idiot- once i put my motor mount back on... the up/down play went completely away :o

[keepnitflying]

Just finished mine and it seams ok.
I removed all the plating from the washers with a small wire wheel on the dremel.
The owb squeaks now without grease is free to move up or down a hair
It seams wrong as the owb rubs on the washer and the washer rubs on the lower block.
Well a flight will tell I guess.

[bobbybe]

when i first changed out the bearing above my owb i found that the bottom washer was almost ground to dust. there was barely any material left! i have an extra 19t owb i could ship out to you if you want it. i replaced it with a 20t but there's nothing wrong with it