OK this is weird. Bosch 3915 SCMS – I’ve had it for about six years and it’s gotten a fair amount of use and abuse, but nothing’s ‘broken’. Last night the machine decided that its’ blade brake would no longer work, and started making a stinky ozone/burning/acrid smell. Also starting to vibrate more than it should. I dunno what might be the problem – maybe it needs new brushes? Anyway, is it worth fixing or better off replacing? I’m not sure I want to use it, ’cause if it bursts into flames I’ll definitely have to go the replacement route.
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Jon, I've got the same saw, and it started doing the same thing last year. Check the arbor nut. Mine was loose.
It is toast, send it to me.
Sounds like brushes. But not sure about the vibrations. When the brake goes, it is usually brushes. good luck,, let us know eh?
d
Electric brakes wear out brushes faster.
It's my understanding that the electric brake works by the current momentarily being reversed,hence wearing out the brushes, so when the brake doesn't work the brushes are gone.
JMHO
SteveC
Update on saw -
Checked arbor nut, removed blade, cleaned blade (pitch buildup causing imbalance?). No dice - arbor nut was tight. Cleaning blade reduced vibration.
Removed brushes, cleaned armature, replaced with new brushes. Saw runs much smoother and gets up to speed faster, but still NO brake.
Next step is to call or e-mail Bosch and see what else can be done.
I thought sure it'd be the brushes. Keep us posted.... this is interesting.View Image
Next step is to check the trigger/switch for fine sawdust build-up preventing the contact being made for the "motor-reverse" when you release the trigger/switch.Sounds to me like you've just got some preventative maint. issues is all.
Last week my guys said the 12" Dewalt on site needed to be fixed, it was making some bad noises. I tried it and they were right. Decided to check the brushes, they were fine. Then I remembered this thread and checked the arbor nut. Bingo! We all felt pretty stupid after that.
Any luck with your saw?
Nah. It stopped being stinky after I replaced the brushes, and I put on a new blade and retightened the arbor nut, but it still has no brake. No big deal, just gotta be a little more careful with it. I'll probably e-mail Bosch about it sometime.