Boca bearings upgrades for Tiger(Avroto) motors.

redridinghood

redridinghood

Member
I went cheap on my CX build and bought MT2814 (770kv) motors. Out of six I got 3 have bad bearings out of the box.
I am thinking of either trashing them or getting some Boca bearing upgrades for them.
Do you think it's a good idea?
How hard will it be to change the bearings, has anyone done so?

Have seen a 15-20% increase in efficiency reported in posts for various applications.

http://www.bocabearings.com/AppByMa...0&ApplicationID=13&MFGSYSID=919&MODSYSID=9226
 

Droider

Droider

Drone Enthusiast
If you are in any doubt save the time go AXI. Just cant see how you can get an extra 15/20% more efficiany fro changing new bearings for new bearings.. I tried to change some on the old Emax I had and it was a right PITA. I just bought new motors in the end.

When you say bad bearings what do you mean? Bell wobbling on shaft? Bell with up and down movement? If so send um back. I have some AXI's that would do you. they have done about 100 hours and still solid

Dave
 


Droider

Droider

Drone Enthusiast
Hard to say what that can be. if there is no movement up and down or side to side I doubt if it is the bearing but again I aint got my hands on um..

Dave
 

yeehaanow

yeehaanow

Member
Bearings are not that hard to change. Once you take the bell off you have to heat the rotor in the oven for about 10 min at about 200 deg F. Don't cook it too long! Then you can tap the bearing out. Done it several times with other motors.
I have the same rattling when spinning by hand on several motors, and there is some play when wiggling it to the side, but so far it hasn't affected the video.
 

J

jes1111

Active Member
Can you see any markings on the bearings? My MT4008's came already fitted with EZO EMQ-rated bearings, made in Japan. My bearing supplier (a miniature bearing specialist in UK) tells me there is nothing better for the job.
 

redridinghood

redridinghood

Member
Yes the bearings do say EZO. In my opinion these bearings are a joke. Ill try to change the bearings with Boca and see if there is a measurable difference.
 


redridinghood

redridinghood

Member
Yes I replaced the MT2814 bearings with boca ceramics (http://www.bocabearings.com/productdetail.aspx?ItemID=21489&MODSYSID=9226&ProductSubGroupID=160)

I find that the stock bearings are a complete joke and probably monkey EZO and not original. If indeed this is what EZO makes then good luck to them.

After replacing the bearings the motors run smoother, quieter and cooler.

Since the price of the bearings is high I would just skip the Tiger motors altogether and get AXI for similar price the MT and Boca bearings cost.
 

O

ovdt

Member
I've started having bearing problems with my Tiger's too. I need to replace 7 of 20 MT2814 motors. I need to buy a lot of extra bearings, since I don't know when the other stock bearings fail.
 

DucktileMedia

DucktileMedia

Drone Enthusiast
Great. Just what I want to hear after buying 8 of them for a new build. I know Chinese will steal everything and anything without shame but I cant imagine they would print EZO on some other bearings. Personally I have had 12 of these tigers and I have only had a shaving of metal in one of them so far.
 

Bartman

Bartman

Welcome to MultiRotorForums.com!!
it's dirt in the bell that usually causes the growling and other unusual noises. compressed air or disassembly has usually cleared it up for me although I also keep a stock of the Boca Abec 5 steel bearings on hand. I also keep spare spring clips on hand as they generally don't survive being removed.

all in all it's about a 5 minute job to replace bearings.
 

J

jes1111

Active Member
I'm consistently mystified by this "Tiger bearings suck" thing every time it comes up. Whilst it's possible, I suppose, that they are fake EZO bearings I just can't understand the bad rap they're getting. I have been reliably informed (by a specialist miniature bearing distributor in UK) that EZO are "as good as you can get" for this application. Yes, you can spend more but, in their professional opinion, you would not see any benefit in either performance or longevity.

Are you "oiling" your bearings? There was a thread recently on the OP forum about this. Someone asked "how often should I oil my bearings?". The fact is: you shouldn't! They are greased at the factory - "oiling" them (presumably with light machine oil) will only serve to wash the grease out of them as well as introduce contaminants.

It's possible that Tiger have poor QC in the factory to pick up on bearings that are damaged during assembly but actually I find that unlikely - they will have the correct press equipment to insert the bearings and shafts cleanly, without the possibility of damage.

So I can only think that bearings are being damaged by impact (of course the bearing takes all the impact in any prop strike incident) - or they are being compromised by "oiling" them (thus washing out the grease and introducing contaminants).

Has anyone taken the shields off one of these "bad" bearings to examine what damage is present?
 

KopterX

KopterX

Member
As jes1111 said, EZOs are made in Japan stuff and they are as go as you can get for this kind of application. I also doubt it that Tiger EZOs are fake. Of course there are better like ceramic, but for sure the flight time will be the same ;-)

However there is one thing to take in consideration. If you crash the copter with motors running or have any other prop strike incident, the EZOs needs to be changed. On single shock like this and EZOs will start rattle. I didn't test prop strike with BOCA yet, but it will be interesting :)
 


yeehaanow

yeehaanow

Member
My Post from pg 1 of this thread :)
Once you take the bell off you have to heat the rotor in the oven for about 10 min at about 200 deg F. Don't cook it too long! Then you can tap the bearing out. Done it several times with other motors.
Click to expand...
 


yeehaanow

yeehaanow

Member
No, the windings and cable jacket are good to about 250-300F. I would try to keep the cable straight and off any metal in the oven though, just for safety.
 

K

Kari

Member
Bartman said:
it's dirt in the bell that usually causes the growling and other unusual noises. compressed air or disassembly has usually cleared it up for me although I also keep a stock of the Boca Abec 5 steel bearings on hand. I also keep spare spring clips on hand as they generally don't survive being removed.

all in all it's about a 5 minute job to replace bearings.
Click to expand...


Bart,

Where did you find spare spring clips for T-m 2814? I tried to look for spares but no success. At the moment i have 2 of 6 qc3328 bad bearings in my cinestar/YS and i think i'll replace them all to BOCA ceramic ones to avoid future problems. I also checked if i replace all motors with AXI 2814/22 but looks like they cannot beat Tmotors/avroto/qc3328/KW4/torxpowwer/Sunnysky/ whatever branded Tigers in terms of efficiency if using 13X6,5 props. Actually regarding to eCalc looks like if i want to go for axi i need to go step bigger with these props. QC3328 has been working very well and cool with these props and looks like it's most efficient motor available.

Kari
 

J

jes1111

Active Member
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.
 

You must log in or register to reply here.
Top