Enlarging a hole that already has been drilled or cored. Generally, it is an operation of truing the previously drilled hole with a single-point, lathe-type tool. Boring is essentially internal turning, in that usually a single-point cutting tool forms the internal shape. Some tools are available with two cutting edges to balance cutting forces.
Single- or multiple-point precision tool used to bring an existing hole within dimensional tolerance. The head attaches to a standard toolholder and a mechanism permits fine adjustments to be made to the head within a diameter range.
Microprocessor-based controller dedicated to a machine tool that permits the creation or modification of parts. Programmed numerical control activates the machine’s servos and spindle drives and controls the various machining operations. See DNC, direct numerical control; NC, numerical control.
Allied Machine and Engineering, a leading manufacturer of hole-making and finishing cutting tools for the metal-cutting industry, has donated various boring bars and inserts to be used with a 1954 Wohlhaupter boring head on the USS Pampanito restoration project.
The Pampanito, a World War II submarine located in San Francisco, opened to the public in 1982. Since then, it has been the goal of the San Francisco Maritime National Park Association to return the submarine to the condition it was in when it left Hunters Point Naval Shipyard in San Francisco in 1945, representing the height of World War II submarine development.
To more efficiently repair and restore the submarine, an onsite machine shop was developed. Volunteer machinists come to the shop, which is tooled up for manual work, and repair or replicate small quantities of parts. Larger quantities of parts are often machined in CNC shops.
After receiving the Wohlhaupter boring head, the museum machine shop contacted Allied Machine to see if boring bars and inserts could be donated to help further the preservation of the vessel. While the donated tools allow history to live on and fuel education, they also demonstrate that the ingenuity of boring tools still holds true today.
The donated tools will be used to bore out parts for waterproof lamp housings that are used on the submarine. These waterproof lamp housings were part of large waterproof binoculars that stayed out of the water when the submarine dove down to 300 feet. The lights enabled the crew to see the reticules or the lines that told them how wide or tall an object was or let them make calculations. Although these were missing on Pampanito, drawings were found, which makes it possible to create replicas.
In the future, the donated Wohlhaupter boring tools will also be used to machine internal grooves in bronze bearings that are used on the submarine.
Because this is an ongoing restoration, three types of projects will continue to be seen in the machine shop:
Pampanito serves as a museum to educate visitors, provide the ability to research the history of the vessel, and offer a historic artifact to preserve and restore.
Richard Pekelney, volunteer machinist and member of the Board of Trustees shared, “We could not restore Pampanito without companies like Allied.”
For more information about the Pampanito and the museum, click here.
For more information on Allied Machine’s line of Wohlhaupter boring tools, click here.
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