Thread: Festool OF1400 some sparking inside (motor)

I just changed the brushes in one of mine after 17 years hard work, same thing as yours was happening, they cost $40 or so and 10 minutes to fit.

All brush-type motors will spark a bit, it's the nature of the beast but when they start to really spark and buzz then there is something not quite right. Step one is to replace the brushes and in 9 out of 10 times that will cure the problem. Do it sooner than later, all that sparking can cause problems with the armature contacts and that is a more complicated problem. Make certain the new brushes can slide smoothly in their holders, sometimes there is a buildup of carbon in the holder that needs to be cleaned out. Perhaps check that the old brushes are not sticking before you order new ones, you could be lucky but if you do keep them in the same positions as they were originally when you put them back.