Abstract: The present invention relates to a rotational cutting machine, it has a base, on the base is first motive power source to bring the cutting blade rotate; near the cutting blade is a fixing tool that tightly holds an object to be cut, on the side the fixing tool is a second motive power source to turn the fixing tool together with the object to be cut; the fixing tool is set on a platform that is adjustable; when cutting an object, the first motive power source turns the blade rotate, while the second motive power source also turns the object to be cut rotate, through the platform that is movable, the fixing tool is moved towards the cutting blade, such that the object tightly held in the fixing tool can be in contact with the cutting blade, the object then can be cut efficiently and accurately.

Abstract: A double-grinding-wheel type drill bit grinding device with a single driving shaft comprising a power source disposed on a base, two grinding wheels being disposed at opposite ends of the single driving shaft extending out of the power source. The grinding device further comprises two pair of first grinding and second grinding seats, each pair of first and second grinding seats being disposed close to the respective grinding wheels at both ends of the driving shaft, a clamping assembly for clamping a drill bit to support the drill bit upon sequential insertion into one pair of the first and second grinding seats, and a positioning device being disposed on a front surface of the base for providing alignment of the drill bit within the clamping assembly prior to the insertion of the drill bit into one pair of the first and second grinding seats. The power source is a pneumatic motor and is provided with a vacuum passage for facilitating dust discharge.

Abstract: The emery wheel grinding machine with adjustable drill bit chuck disclosed herein has an adjustable chuck in which is provided with a T-bushing having an outer flange formed at one end thereof. The outer flange is provided with several pairs of stop traps along its circumference, whereas the number of stop traps are determined according to the number of cutter blades to be shaved. Several stop pins are formed on the surface of the outer flange to control the turning angle of the drill bit or the cutter. The T-bushing further has a taper hole in it. When the chuck head which holds the drill bit or the cutter is inserted into the taper hole, the cutter blade can be in contact with the emery wheel with a certain tilted angle thereby allowing the cutter blades of various length and number to be effectively shaved, ground and finished.