Limited vertical access drilling machine

A positive-feed drill motor assembly comprising:

• a positive-feed motor comprising a spindle which rotates around a spindle axis and simultaneously translates in a direction parallel to the spindle axis;
• a gearbox comprising a plurality of gears, each having a different axis of rotation, comprising a driving gear rotated by the spindle, at least one intermediary gear rotated by the driving gear, and a driven gear rotated by the at least one intermediary gear, the driven gear configured to rotate a drill-bit around a drill-bit axis that is offset from the spindle axis;
• and
• a clamp comprising an upper clamp arm and a lower clamp arm which move relative to one another;
• wherein the clamp further comprises a pilot-hole finder which when disposed in a first position starts the positive-feed motor or begins clamping with the clamp and when disposed in a second position the pilot-hole finder turns off the positive-feed motor or retracts the clamp;
• wherein the gearbox and a drill-bit attached thereto are configured to simultaneously translate with the spindle in the direction parallel to the spindle axis as the spindle rotates around the spindle axis.

A method of drilling comprising:

• moving an upper clamp arm and a lower clamp arm of a clamp relative to one another to clamp a part between the upper clamp arm and the lower clamp arm;
• rotating a spindle of a positive-feed motor around a spindle axis;
• rotating a plurality of gears of a gearbox with the spindle;
• rotating a drill-bit with the plurality of gears around a drill-bit axis which is offset from the spindle axis;
• simultaneously translating the spindle, the gearbox, and the drill-bit in a direction parallel to the spindle axis as the spindle rotates around the spindle axis;
• and
• starting the positive-feed motor or beginning clamping the part with the clamp when a pilot-hole finder is disposed in a first extended position in a pilot-hole of the part and turning off the positive-feed motor or retracting the clamp from the part when the pilot-hole finder is disposed in a second compressed position as a result of the drill-bit contacting and compressing the pilot-hole finder after drilling through the part.