Bosch GCM 8 SDE - Mitre Saw

[chillydk147]

Hello, I had my Bosch Mitre saw for about 2 years now but it's recently started to make a humming sound when powered on, below is an example video of what this sounds like at the top speed of 6. It still cuts and there's no wobble with the blade but I'm guessing this is the beginning of some part failure. Any ideas what could be the issue here?

 

[Spectric]

It sounds obvious that the speed is unstable, if you have the trigger hard on then it should reach the speed you have set and hold it which it sounds like it is not.

 

[Sideways]

Bosch pro gear has a 3yr warranty if you registered for it.
Call it in pronto

 

[chillydk147]

It sounds obvious that the speed is unstable, if you have the trigger hard on then it should reach the speed you have set and hold it which it sounds like it is not.

Thanks, I'm definitely pressing the trigger fully in but the speed is still varying

 

[chillydk147]

Bosch pro gear has a 3yr warranty if you registered for it.
Call it in pronto

I'm hoping it's related to some part I can repair rather than going through a warranty process

 

[Spectric]

That sounds like the speed control module, look at this site

https://www.mtmc.co.uk/product.aspx...MI46rZ1KWPggMVksftCh0F7AzSEAQYASABEgI19fD_BwE
part 28 is called the speed governor and contains the speed control dial as seen in lowest picture, worth replacing !

 

[chillydk147]

That sounds like the speed control module, look at this site

https://www.mtmc.co.uk/product.aspx...MI46rZ1KWPggMVksftCh0F7AzSEAQYASABEgI19fD_BwE
part 28 is called the speed governor and contains the speed control dial as seen in lowest picture, worth replacing !

View attachment 168604

View attachment 168607

Thanks for your helpful reply, I think I'll replace this component

 

[chillydk147]

@Spectric - Thanks for your advice, I know it's a few months later. I decided to keep using it as it was with the humming sound but it got progressively worse to the point of being unusable so I ordered the replacement Speed Governor and now it's working great again

 

[Spectric]

Pleased to have been able to assist .

 

[artie]

I'm hoping it's related to some part I can repair rather than going through a warranty process

I know it's too late now, but I would have been all over the warranty.

@Spectric - Thanks for your advice, I know it's a few months later. I decided to keep using it as it was with the humming sound but it got progressively worse to the point of being unusable so I ordered the replacement Speed Governor and now it's working great again

But you don't have a warranty anymore.

 

[chillydk147]

I know it's too late now, but I would have been all over the warranty.


But you don't have a warranty anymore.

It was actually a 2nd hand purchase and warranty wasn't an option for me

 

[artie]

It was actually a 2nd hand purchase and warranty wasn't an option for me

Ah. that's a good reason for not making a claim.

 

[Blister]

Successful repairs allways give I nice feeling , Good to get things working again, Well done .

 

[chillydk147]

Successful repairs allways give I nice feeling , Good to get things working again, Well done .

Yes indeed and not the easiest part to replace giving that the motor had to be removed also