Stihl fsa 57 battery strimmer

[Wonkydonkey]

Just a general question really about stihl battery strimmers and possibly other stuff. Using wrong bearings in the wrong place.

The problem was fsa 57, it starts for a few seconds and then cuts out. It’s not the battery.
Upon closer inspection. The bottom bearing on the geared drive shaft of the motor had seized, marked in yellow in pic.

The bearings top and bottom are 609 2zz c3 . The motor needs cool air and this is supplied via the sort of fan #4 in the pic.
Imho Which in normal use here in the uk will supply damp moist air.

Spoiler, an email to stihl asking why this bearing is used and not a 609 2rs c3. They completely ignored the question and said battery strimmers should not be used when the grass is damp or wet conditions.

I pulled the Seized bearing and replaced it with a 2rs c3 , it’s a £3 inc postage where as the whole unit #1 is £85

I believe this is not the first case as another friend had a similar problem (I never looked at it, it’s what he told me) and the stihl dealer said they don’t repair them. But you can buy another strimmer @ £145..

Anyway here’s the pic etc.

 

[EFSM]

Stihl apparently has a fascination with shielded bearings instead of using proper sealed bearings. On the gas trimmers that use a clutch bearing (I primarily see it in 4-mix), most of them are shielded . I replace quite a few of them because they go bad quickly in our climate. I suppose they are lower drag, but not by much, and only when they are new.

 

[Wonkydonkey]

Stihl apparently has a fascination with shielded bearings instead of using proper sealed bearings. On the gas trimmers that use a clutch bearing (I primarily see it in 4-mix), most of them are shielded . I replace quite a few of them because they go bad quickly in our climate. I suppose they are lower drag, but not by much, and only when they are new.

I was reading about the drag aka resistance etc of the different bearings 2zz & 2rs. however there is always an answer !.. but it cost more .. lol
It’s called 2ru.

I’m sure you already know the 2ru shielded bearings are as good as the 2zz but less drag than the 2rs . I think it’s really a manufacturing issue cost rather than the cost of the bearings.

Anyhow, I wonder if this is the only stihl strimmer model affected with this type bearing and design.?

I’m just putting it out there so others know that this bearing fails due to cutting damp grass and stihl says don’t cut wet or damp grass but everybody know grass is wet 99% of the time ..in the uk .

And those Who think battery powered trimmers are better

 

[ray benson]

I was reading about the drag aka resistance etc of the different bearings 2zz & 2rs. however there is always an answer !.. but it cost more .. lol
It’s called 2ru.

I’m sure you already know the 2ru shielded bearings are as good as the 2zz but less drag than the 2rs . I think it’s really a manufacturing issue cost rather than the cost of the bearings.

Anyhow, I wonder if this is the only stihl strimmer model affected with this type bearing and design.?

I’m just putting it out there so others know that this bearing fails due to cutting damp grass and stihl says don’t cut wet or damp grass but everybody know grass is wet 99% of the time ..in the uk .

And those Who think battery powered trimmers are better

Played around with skate board bearings and found quality of the bearings to be an issue. Never settled on one brand but SKF/Timken/NTN/other name brand industrial bearings should be better than the no name ones I ran across.

 

[RCBS]

'said battery strimmers should not be used when the grass is damp or wet conditions.'

 

[EFSM]

I wonder if this is the only stihl strimmer model affected with this type bearing and design.?

As I said, I struggle with the clutch bearings failing on many of their gas models. They use an NTN 6201ZZ bearing, which is a good bearing, but totally in the wrong application. I'm not familiar with their electric/battery models.