The tool shown in the figure is a drill guide that can adapt to a curved or flat surface. The main function of the adaptable drill guide is to keep the axis of a drill perpendicular to the surface at the location of the hole to be drilled. The tool can also be used to guide a reamer into a drilled hole, to control the depth of drilling or reaming, and to guide tools other than drills and reamers. With simple changes in dimensions, the basic design of the tool can readily be adapted to drill bits and reamers of various diameters.

A vacuum pump and connecting hose are needed to operate the tool. The tool includes suction-cup feet; it is attached to the surface of a workpiece by applying vacuum to the suction cups. In this way, it can even be attached to a lubricated surface without need to remove the lubricant.

Suction Cups With Tooling Balls Recessed Within Them provide attachment and a stable geometric reference for the drill guide.

Other aspects of the design and use of the tool are best described in terms of the following typical sequence of operations:

  1. A pointer is inserted in the drill guide, extending past the suction cups.
  2. The drill guide is maneuvered to place the pointer at a desired marked location (e.g., the center of a hole to be drilled) on the workpiece.
  3. With the pointer pressed gently on the surface at the desired location, the drill guide is moved to bring the suction cups into gentle contact with the surface.
  4. Vacuum is applied, causing the suction cups to pull the drill guide toward the workpiece surface until tooling balls mounted inside the suction cups make contact with the surface, providing a stable drill-guide base.
  5. The pointer is removed from the drill guide.
  6. A drill, reamer or other tool bit, mounted in a modified holder attached to a conventional hand tool, if necessary, is inserted in the drill guide.

Prior to the development of this tool, it was necessary to either rely on a skilled technician or else use a complex, computer-controlled five-axis milling machine to make a hole perpendicular to an arbitrary surface at an arbitrary location. In the case of a skilled technician, the degree of accuracy and repeatability of the hole is open to question. In contrast, this tool makes it possible to locate and orient drilled holes accurately and repeatably, without need for expensive machinery like a five-axis milling machine.

This work was done by Earl T. Daley and Lawrence W. Whiteside of Ames Research Center.

Inquiries concerning rights for the commercial use of this invention should be addressed to

the Patent Counsel
Ames Research Center; (650) 604-5104

Refer to ARC-14259

NASA Tech Briefs Magazine

This article first appeared in the September, 1999 issue of NASA Tech Briefs Magazine.

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