The CD-C1000 is a 4 speed high torque gearbox that is an excellent choice for large diameter and deep core drilling. It is capable of drilling holes up to 60" in diameter.
It will accept most 400 HZ motors with a 3½” X 3½” flange mount and 5/8" spline coupler drive (AN2001). It has approximately a 3.7:1 ratio between low and high gear.
It is very strong and very well liked by core drillers.