Abstract: A pole sander is provided including an elongate body having a first end and a second end, an electric motor, and a sanding head attached via a pivot mechanism to the first end of the elongate body. The sanding head includes a hood including a plate and a peripheral wall formed on the underside of the plate around an edge of the plate; an output spindle that projects from the hood and is rotatably driven by the electric motor around a rotational axis; and a brush ring mounted on the underside of the plate adjacent the edge of the plate inside of the peripheral wall. The brush ring is attached to the plate via a spring comprising at least one of a leaf spring or a wave spring.

Abstract: In various embodiments, single-crystal aluminum nitride boules and substrates are formed from the vapor phase with controlled levels of impurities such as carbon. Single-crystal aluminum nitride may be heat treated via quasi-isothermal annealing and controlled cooling to improve its ultraviolet absorption coefficient and/or Urbach energy.

Abstract: A pole sander is provided including an elongate body including a passageway for passage of air, an electric motor, and a sanding head attached via a pivot mechanism to a first end of the elongate body. The sanding head includes a hood including a plate and a sidewall to form a chamber, an output spindle projecting from the hood and rotatably driven by the electric motor, and a tubular passage including a first end forming an opening and a second end coupled to an aperture formed through the plate. A flexible pipe is disposed between the passageway at the first end of the elongate body and the opening of the tubular passage to fluidly connect the passageway to the chamber. The tubular passage is oriented at least partially around a portion of the output spindle in a turning direction of the output spindle and extending angularly from the plate.

Abstract: A power tool for forming a channel in a work surface includes a first section carrying a rotatable shaft having a shaft axis and a second section that engages the work surface; a cutting disc having a substantially circular blade provided on the rotatable shaft; a first support portion on one side of the cutting disc and a second support portion on the opposite side of the cutting disc which cooperate to hold the cutting disc at an oblique angle relative to the shaft axis. A first locking feature of the first support portion and a second locking feature of the second support portion extend through a circular opening of the cutting disc and cooperate to resist relative rotation of the first and second support portions. The first section is movable relative to the second section to move the cutting disc into and out of engagement with the work surface.