HMT radial drills are based on a proven design. The uniqueness of this design is in its combination of two apparent contradictions: the machine is massive and highly rigid, yet capable of feather-touch maneuvering.

Light Centering

Unclamped, the massive arm swings light. It is centered by a ball bearing at the top of the column and by roller bearings around the skirt, and hangs on a thrust ball bearing supported on a spring plate. The drill head, balanced on two ball bearing rollers, runs on the ground flat top face of the arm slideway.

Rigid Clamping

The electro hydraulic clamping ensures clamping after light sensitive centering, without the slightest shift.

The sleeve locks to the column by three double row ball bearings on eccentric cams which close powerful 30 degree V clamps and draw down and lock the sleeve to the base of the column.

The arm locks to the sleeve by squeezing the deep boss to practically fuse arm and sleeve together. The drill head is locked against the lower V slide by a powerful cam action.

With a hand on the drill head traverse wheel the operator can centre the drill, press the push button lock, and then, without shifting position, the head locks to the arm, the arm locks to the sleeve, and the sleeve clamps down to the column.

For tool changes, without losing centre, the operator presses the elevating button, and the arm-to-sleeve clamping alone is relieved. After vertical traverse, and tool change, the arm reclamps to the sleeve. For in-line drilling, the star nut provided clamps the sleeve to the column.

Feeds

Single lever controls select any of six different feeds from 0.005 to 0.05 inches per revolution (0.005, 0.008, 0.012, 0.020, 0.030, 0.050). The log scale calculator makes fast, easy selections for drilling, tapping and reaming.

Positive overload protection to all elements of the machine is provided by an escape mechanism in the feed drive. Radially located steel balls transmit torque pressed onto a notched plate. The balls ride the notches with the slightest overload.

The depth stop can be set with precision, by means of a vernier scale on the large depth dial.

Head

The drill head has a short, compact drive path through hardened and ground gears. Twelve speeds forward and twelve in reverse range from 40 to 1800 rom (40, 56, 80, 112, 160, 224, 315, 450, 630, 900, 1250, 1800). Multiple disk clutching insures smooth engagement and extremely good braking and reversals. The clutch lever in the neutral position automatically engages the brake. rapid withdrawal speeds can be selected for tapping.

The super finished quill is ground and honed to the head bore, and is located directly next to the arm. This design provides powerful thrust with little or no deflection.

Special preloaded self-aligning double row ball bearings, specially designed to withstand axial loads encountered in boring operations, are used.

Arm Bearing Support

A split girdle is located at 225 degrees, providing full bearing support directly behind the arm. This offset split, unlike typical 180 degree splits, results in a full bearing girdle which resists deflection, sag and wear.

Accessories

A universal table for angular work setting has two 90 degree faces and an accurately graduated scale for precise positioning.

Standard equipment includes a coolant system which has a 10 gallon sump and 1/4 hp pump for applications requiring a continuous supply of coolant.

Specifications