We have an electric knife - many years old, but still electrically sound.
Reciprocating knives are getting blunt! We make home made bread [in a machine] and cut each loaf into slices.
Knives are serrated, the 'grind' is flat on an angle to the teeth, each of which is then ground in a scalloped shape.
I'll see if I can attach a photo, but the question is this -
Can the knives be sharpened, or is it a case of get a new one?