Counter Bearing Install Pics Needed

[KidHeli]

Originally Posted by jointer

What i know about ceramic bearing balls is that they are more fragile then steel, so i believe that is the reason why not to use them in device with quicky changing forces (like motor).

The CB is there to prolong the life of the Pyro bearings, it is doing it right if done correctly - after 35 easy flights with stock Pyro and CB, the top motor bearing was heavily leaking grease and barely moving.
To have it working right, you need to loosen the motor axially (to avoid axial load on the smallest, top bearing), lets say 0.2mm.
Then, you assemble everything together and remove the play by assembling tight this parts: motor locking collar - pinion - counterbearing.
This way the top bearing is "floating", it is not touching the rotating can, so axial force does not have effect on it, all axial force is taken by the counterbearing, which is MUCH bigger then the small top bearing and easily replaceable.
On clockwise TDR, the axial force is "into" the counterbearing.
(on CCW, the motor would spin on the other direction, so the CB would be probably useless, because the main axial force would be "out" of the CB, so the middle bearing would suffer)
It is difficult to describe, but easy to understand for someone, who already replaced bearing in the Pyro and have some machanical imagination.

I just disassembled my Pyro, the smallest top bearing is rough (so i will replace it) but not as bad as it was the first time, this is after about 300-350 flights.
So, this worked 10 times better then before.
The diffrence is quality bearings and different assembly procedure then what you get from the Kontronik factory.

I found old photo of the stock damaged bearing.
Also photo i took on the first bearing replacement - the magnets are brushed by the stator, it is probably not well balanced motor.

Edit: wrong math, i have about 650 starts and i was replacing the bearings around 100th flight, check after 150 more, so i done at least 500 flights on the new bearings.
The photo is either my motor at 100th flight or motor from TDR my friend have, after 35 flight, i do not remember.

Cool thanks. That bearing looks rough!

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[Vinger]

Originally Posted by KidHeli

Vinger, I think I'm following you now. There should be a small gap, say 0.2mm, at the top and bottom to relieve the axial load. That way the small bearing in the Pyro isn't applying pressure on the pinion and the pinion isn't applying pressure to the CB creating preload on the system.

Is this correct?

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You do not want any pre-load on any of the bearings. For the CB to work properly the pinion needs to run against it during power transfer, without the motor shaft being pulled down and so creating an axial load on the motor bearings.

On a CW rotating head the pinion wants to push down on the CB due to the helical gear train, you want this axial force to be relieved by the CB and NOT the motor bearings, SO the pinion needs to be as close to the CB WITHOUT pre-load when it is stationary and motor bolts TIGHTENED ie no gap between pinion and CB after assembling the motor to the motor mount with the three bolts going through the CB unit.

[jointer]

BTW what was working for me is tightening the pinion after fully tightening the CB support.
You can then tell if there is any preload, by trying to turn the pinion without grub screw. I assemble with tiny bit of preload (if it is possible) because i found the inner race of the CB wears out the shim over time, no matter how i do it.
You want the shaft to stay on spot, so both sides pinion-CB and pinion-locking collar should not have any play, i think.
It is easy to see on a heli which have few dozens of harder flights.

[johnjonfenomenon]

when you buy the counter bearing, does it come supplied with a variety of shims? Also I ordered a 700-520L motor as this is what was in stock. Do I need to cut it to make it work?

[Egroeg]

I have not read the whole post so please excuse...
If this of any use to you...
I installed the pinion and shimed it accordingly to be on the same plane as the plastic gear ( meaning neither lower nor higher).
I gave some tick tack sound play to make sure the two were not hard pressed against eachother.
And finally...I THOUGHT IT WISE ON MY PART TO LOOSEN THE GRUB SCREW ON THE PINION ONCE ALL WAS INSTALLED...TO RELEASE ANY AXIAL FORCE THAT MIGHT BE THERE ONCE INSTALLATION WAS COMPLETE.
There was some axial tension that was released once the grub screw was loosened and retightened (with lock title ).
The fact that the 2 gears have slanted teeth...tends to push them away from another and also there is a tendency for force to be exerted on the direction of the shafts ( up down).
So the pinion seems to be pushed DOWNWARD towards the counter bearing...where the shims prevent it from exerting a force on the shaft of the motor.

[Egroeg]

Me and a friend are expecting the finned motor mounts from GMAURO to be sent to us shortly.
So since I will be replacing the stock mount with the finned one...I will be removing the motor and will be able to closely inspect the shims and counter bearing and of course I will pop the motor open to make sure everything is okay...
I must have about 150 flights or so?
I have totally lost track...maybe more...so the inspection is coming at a good time.

[KidHeli]

Originally Posted by johnjonfenomenon

when you buy the counter bearing, does it come supplied with a variety of shims? Also I ordered a 700-520L motor as this is what was in stock. Do I need to cut it to make it work?

you ordered the long shaft so yes you will need to cut it to size, the CB does come with the kit and will need to be installed with the Pyro given it has smaller bearings than say a Scorp motor. It will have all the shims needed to get correct positioning.

[Dumbthumb75]

Originally Posted by johnjonfenomenon

when you buy the counter bearing, does it come supplied with a variety of shims? Also I ordered a 700-520L motor as this is what was in stock. Do I need to cut it to make it work?

It is about 35mm from top of motor mount to top of ESC plate, so the 700L shaft will have to be cut.

Are you buying the CB separately? If so I would assume that no shims are included.

The CB, with some shims, is included in every kit, however I had to add a couple extra to fill the gap.

[johnjonfenomenon]

Originally Posted by Dumbthumb75

It is about 35mm from top of motor mount to top of ESC plate, so the 700L shaft will have to be cut.

Are you buying the CB separately? If so I would assume that no shims are included.

The CB, with some shims, is included in every kit, however I had to add a couple extra to fill the gap.

No Im not buying seperately I thought it needed to be bought seperately. My kit is coming in April. Therefore I am building my list. There are 3 versions of the 700-520. The medium is out of stock so they have the L and the standard. would the standard work without needing to cut. Or is the M the one that is really needed?

[KidHeli]

i've never seen the m version but the standard shaft is what Jan recommends in the instructions.

Here it is at RH in stock http://www.readyheli.com/Kontronik-P...r_p_35794.html

[johnjonfenomenon]

Thanks. I will modify the purchase. But as for the M length here it is.

http://www.readyheli.com/Kontronik-P...r_p_38023.html

[bitsnpieces]

The standard shaft is the one you want.

[KidHeli]

Originally Posted by johnjonfenomenon

Thanks. I will modify the purchase. But as for the M length here it is.

http://www.readyheli.com/Kontronik-P...r_p_38023.html

looking at your link and comparing it to the one i linked you to they seem to be the same motor only the 52M is $10 more

go with the one i linked you to and you'll be set and save $10

[Groucho_]

I'm glad I somehow stumbled on this thread yesterday...

For some reason I realized that when I assembled the counter bearing, I had left the 0.2mm space there even after the three screws were tightened thinking that was the way it was meant to be.

Now I added a .2mm shim, and the bearing is flush with the pinion.

I did notice that you have to pay extra attention to the pinion to intermediate gear mesh when this is done, as with no axial play available to the pinion, there will be points on the gear where the clack-clack sound indicating correct pinion to gear mesh, just does not happen. Previously, if the sound could be heard at one point on the gear, it would be heard throughout, probably due to the pinion being able to be pulled axially downwards instead of getting 'stuck'.

[CyprusFlyer]

Just found this thread, have to agree with most that the most logical way was to shim the pinion to get the gears exactly level, then I tightened the motor bolts with the grub screw loose. Finaly locktighted the grub, applied a little downward pressure against the counter bearing then tightened up the grub fully. No possibilty of loading the motor bearings, that method made complete sense.

[Groucho_]

Hmm, well I'm not sure that was such a great move now...

When I tested the setup, the vibrations were too elevated...

I went down from .6mm shims to .5mm which was better, but still high.

Went back to .4mm, but the vibes didn't get back to normal - They're just a bit better than .5mm shims...

Presently have .5mm shims installed, and have high up/down vibes - nothing else.

I can't figure out how to get rid of them though tried quite a bit of meshing and shimming and whatnot...