There is a slight sparkling in my drill. What could be the reason? I received a product and checked for first time by plugging it into the socket. I wonder whether it is common or a serious problem.
If the motor has brushes some arcing is normal even with high quality equipment, cheaper models usually have more arcs that are visible because the armature is usually rougher. You may notice a decrease in the quantity of arcs as the brushes seat to the armature, I regularly dust my brushed motors with dry compressed air to reduce buildup and on big motors. Usually higher voltage this reduces the chance of flash over that can do a fair amount of damage. + for both comments.