Boca bearings upgrades for Tiger(Avroto) motors.

[PaNt]

i'll measure a motor shaft when i go downstairs. i doubt Tiger would deliberately undersize the shafts so you have to buy bearings from them but who knows?!?

Do you think its a problem.. the lateral play is very very small

 

[DucktileMedia]

I have this small lateral play as well with the BOCA's. It didnt show up in the video too much if at all. But it is nice knowing your new bearings are as good or better than what china stuck in them from the factory.

 

[PaNt]

I have this small lateral play as well with the BOCA's. It didnt show up in the video too much if at all. But it is nice knowing your new bearings are as good or better than what china stuck in them from the factory.

I found the problem guys..!
I put 2xwashers that Bartman send me not one and the lateral play went away..1 i couldnt see the up and down play because of the magnets..

Now i have 0 play..!!!
Also on some you could not put 2 washers then you have to un tighten the shaft and you pull it out a little..! Thats all..!

But its a headache i wont do it to all motors..! do you have a problem with the small play Iris??

 

[DucktileMedia]

I never thought of adjusting the actual end play with the screws. I think thats the way to go as long as the mark from the set screw doesnt allow you to make a very small movement without finding the previous notch in the shaft. But 2 washers would be way too much for what I have. There seems to be about .003" play. I just dont see how that allows for the lateral play. Now if you made it too tight you might be squeezing the races up on the balls eliminating the lateral play but now you have a lot more mechanical friction than you ideally want. who knows. I'm thinking if you are playing around you can do whatever you want. But if you are making money with these things or trying to get buttery perfection I would not hesitate to just have a few spare motors on hand.

 

[PaNt]

I never thought of adjusting the actual end play with the screws. I think thats the way to go as long as the mark from the set screw doesnt allow you to make a very small movement without finding the previous notch in the shaft. But 2 washers would be way too much for what I have. There seems to be about .003" play. I just dont see how that allows for the lateral play. Now if you made it too tight you might be squeezing the races up on the balls eliminating the lateral play but now you have a lot more mechanical friction than you ideally want. who knows. I'm thinking if you are playing around you can do whatever you want. But if you are making money with these things or trying to get buttery perfection I would not hesitate to just have a few spare motors on hand.

i will leave it as it is.>! and i will check it on flight..!

 

[Bartman]

i will leave it as it is.>! and i will check it on flight..!

hi guys,

sorry but I can't really agree with what you're saying. I felt a couple of new Tiger motors and they have the same little bit of play that you're talking about. keep in mind that with a load on the props you'll get the same tightening up of everything that you're getting with the extra washers. electric motors can have that little bit of play, what we're talking about is roughly .005" which is nothing. once the props start turning that play is pulled tight by the props. i've been making a test stand this afternoon so i'll have real data pretty soon.

bart

 

[PaNt]

hi guys,

sorry but I can't really agree with what you're saying. I felt a couple of new Tiger motors and they have the same little bit of play that you're talking about. keep in mind that with a load on the props you'll get the same tightening up of everything that you're getting with the extra washers. electric motors can have that little bit of play, what we're talking about is roughly .005" which is nothing. once the props start turning that play is pulled tight by the props. i've been making a test stand this afternoon so i'll have real data pretty soon.

bart

Yeap thats what i said i will not change anything i will leave the little play..!

 

[rocjock]

Bump...

awesome thread. with Bart's video and tool, i think I have the confidence to go forward replacing the bearings on my set of 2814's.

Could someone point me in the direction of,
1) a place to find replacement bearings for T-Motor 2814-11 kV710... i see MontoRC, where i bought my motors, has bearings for avroto 2814. not sure if its the same.
2) a place to find replacement spring clips/washers *answered. the tool comes with 20 of each i believe. if not, mcmastercarr?

 

[Bryharv]

I have a hot motor on my Cinestar8, wondering what could be causing it. This one runs sometimes up to 160F while all the others are around 110-120F. My machine is perfectly balanced, so it's not that.
I was going to try changing the bearings, but after reading this thread I'm not sure it would do any good. The bearings on the offending motor feel smooth as butter, as they should since this motor is nearly new, with only about 20 hours on it.

If anyone here has any ideas of what could be causing the excess heat, I'd appreciate your input!

thanks!

 

[DennyR]

I spend a lot of time reworking my motors, rewinds and shaft clearances in particular. But the most crucial part is the balancing of the bell. This is done with an Iphone app called vibration and it is so sensitive that it can hear the bearing noise. If you have any noise in the bearings you simply cant balance your motor properly. When I strip a new motor the bearings are boiled in synthetic motor oil which usually gives them a better start in life but any impact from a crash or a drop on the floor and they are scrap. Heating the housing for disassembly and assembly is vital. I think most bad new motors have been put together in a rush and some just don't have any oil in them. I found that some of the Hackers were quite good quality. Curved magnets for a start.

 

[DennyR]

I have a hot motor on my Cinestar8, wondering what could be causing it. This one runs sometimes up to 160F while all the others are around 110-120F. My machine is perfectly balanced, so it's not that.
I was going to try changing the bearings, but after reading this thread I'm not sure it would do any good. The bearings on the offending motor feel smooth as butter, as they should since this motor is nearly new, with only about 20 hours on it.

If anyone here has any ideas of what could be causing the excess heat, I'd appreciate your input!

thanks!

Try checking the resistance of each phase, a short across a few windings wont stop your motor but it will run rough. also the settings applied to each ESC Timing etc.

 

[gtranquilla]

Are you saying that you strip new motors and boil the bearings in synthetic oil?.....

I spend a lot of time reworking my motors, rewinds and shaft clearances in particular. But the most crucial part is the balancing of the bell. This is done with an Iphone app called vibration and it is so sensitive that it can hear the bearing noise. If you have any noise in the bearings you simply cant balance your motor properly. When I strip a new motor the bearings are boiled in synthetic motor oil which usually gives them a better start in life but any impact from a crash or a drop on the floor and they are scrap. Heating the housing for disassembly and assembly is vital. I think most bad new motors have been put together in a rush and some just don't have any oil in them. I found that some of the Hackers were quite good quality. Curved magnets for a start.

 

[cbpagent72]

Sent from my SPH-L720 using Tapatalk 2

 

[DennyR]

Are you saying that you strip new motors and boil the bearings in synthetic oil?.....

Yes. That is before I do any other work, because it is a waste of time if the shaft and bearings are not correct in the first place.
You need a high performance oil, a modern F1 engine as an example would not run for very long on normal motor oils.

 

[gtranquilla]

I am looking for local North American distributors/suppliers of metric circlips and shim washers for the 686ZZ or equivalent bearings..... that are mounted on a 4 mm diameter motor shaft. The 686ZZ bearings are a very common size that is 13mm x 4mm ID by 5mm high. Anyone know where to look for these?

Circlips and shim washers from here: http://www.calebcomp.co.uk/ (the shim washers are VERY important for allowing the correct amount of end-play.
Bearings from here: http://www.smbbearings.com/

It's worth buying a good quantity of circlips and shim washers - "best practice" would be to change them for new ones every time they are removed. In the overall scheme of things, the cost is negligible and the peace of mind worthwhile!

Similarly with bearings: to my mind the best strategy is to buy EZO bearings in quantity and change them out automatically, without hesitation, if you experience any kind of prop strike or even suspect that a particular bearing is "suspect". Remember, too, as Bart has said above - if you think a bearing is noisy, first take off the bell and make sure everything is clean: dirt/grit inside the bell will feel exactly like a bad bearing. The only effective way to check a bearing is while you have full access to it - remove it entirely, put a pencil into the bore and rotate it manual - you'll be able to feel any problems immediately. In many cases the oven trick is not even necessary - a very gentle push/tap with a plastic rod or similar should remove it. And never put any oil on one of these bearings - they are grease packed at the factory - oil will only wash the grease out and aid premature failure.