subject: Why Do Smoke And Sparks Come Out Of My Power Tool? [print this page] Seeing smoke or sparks flying out of your power tool is certainly not a normal nor desired behavior. Despite the scare, though, of a fireworks display breaking out of your power drill, there is a bright side amidst the chaos. Firstly, there are really only two places on a power tool where one might find said smoking or sparking action: either from the dust vents or from the switch assembly. Knowing this, and knowing where the smoke or sparks are coming from, helps us determine exactly where our problem is which puts us only a few steps away from a completely revived power tool.
To begin, if you experience any sparks or smoking form the ventilation points on your tool, there are just three scenarios to consider: One, your armature is bad. Two, your field is bad. And three, both your armature and field are bad. In either case, a bad field or armature is most likely the result of your having overheated, over-loaded, or in any other general sense, misused or abused the tool. You see, although many of us like to believe that our power tools are invincible, they are only designed for certain applications and with certain capacities. When pushed past their limits, chances are your tools are going to burn-up a component or two. Ultimately though, in the event of a bad field or armature, one or both of them must be replaced.
Secondly, if you experience sparking or smoke from the switch assembly, there is really only one explanation and that is simply that your switch is bad. In this scenario, your switch's present state of "badness" was likely caused by a shortage in the assembly which, in turn, was most likely caused by moisture damage to the switch, or slightly less likely, by overheating in the tool. In either case the switch must be replaced.
Determinimg whether the bad-boy behind your suffering power tool is your field or armature is as simple as checking their assemblies for heat damage. Heat damage will appear as any kind of colorful or dark discoloration, or like melting, charring, or burning of the armature's and field's wiring, wiring insulation, or assembly. Any heat damaged component will require fast replacement. While checking the field and armature, you may also want to look at the armature's commutator. If the bars do not form a smooth and complete circle it may cause the brushes to jump around and spark. This form of damage, however, although equally bad and equally needing of replacement, is likely not today's culprit. Also be aware the heat damage to the field and armature generally occurs simultaneously i.e. if one is damaged it's likely the other is too. When damage to the armature is detected early, this can sometimes prevent the spread of damage to the tool's field, however, if the field is damaged the armature is almost certainly in trouble as well.
So, in short, be good to your power tools and if you should experience smoke or sparks emitting from them, a simple parts replacement for any heat damaged component is all the doctor will order.
