When cleaning rollers always have the unit unplugged. The rollers will need to be cleaned fairly regularly (depending on usage), to reduce build up of wood resin on the rollers. Build up of wood resin can cause drag on the rollers making for uneven planing / thicknessing. We recommend using methylated spirits to clean resin build up off of the rollers. It is advisable not to employ this method too regularly as it will have a damaging effect on the rubber sleeves on the rollers. If the build up isn't very substantial it is recommended using "wood off" and some mildly soaped water.