Abstract: A power tool comprises a base unit and a motor unit. The base unit includes a handle and a first electrical connector. The motor unit includes an electric motor and a second electrical connector. The motor unit is configured to be releasably connected to the base unit. An electrical connection is established between the first electrical connector and the second electrical connector when the motor unit is properly connected to the base unit. A sensor is configured to determine whether the motor unit is properly connected to the base unit.

Abstract: An apparatus for determining one or more optimal operating parameters for debarking wood is provided. The apparatus has a scraper and an actuator configured to adjust the position of the scraper toward a sample portion of the wood to scrape a surface of the sample portion of the wood with a scraping force. The apparatus also has a force sensor operatively associated with the scraper for detecting the scraping force. A light source impinges light on a scraped surface of the sample portion. A light detector detects a light image defined by light from the light source reflected by the scraped surface. A controller is operatively associated with the force sensor and the light detector. The controller has processing means to determine the one or more optimal operating parameters based on signals relating to the scraping force and signals relating to the light image. The one or more optimal operating parameters are relevant to debarking wood proximal to the sample portion.