2020-11-27 06:35:40
The year was 1928, the height of the Roaring Twenties, and the United States was experiencing economic prosperity. It was also the year a special measuring precision optics machine had arrived on a ship from Europe. Its new home was the General Electric plant in Lynn, MA, a town located 14 miles northeast of Boston. It was the SIP MP4 machine, with serial number 88.
Societe Genevoise d’instruments de Physiques, or SIP, was a Swiss-based manufacturer of products and instruments for physics and optics that was acquired by Starrag in 2006. In the early 1900s, the engineers at SIP built a wide range of machinery, including refrigeration compressors, telescope mounts and other scientific instruments.
The first machine tools built by SIP were thread grinding machines, beginning in 1908. The first SIP industrial machine tool was produced in 1921. Although SIP had little experience in jig boring machine tools, the MP4 evolved from “machine à pointer” or a machine with great precision. It had a 20” x 24” (500 mm x 600 mm) worktable and was the first SIP machine that could locate and bore a hole with high precision. The MP4 was manufactured from 1921-29.
The SIP MP4, serial number 88, has a storied past. After its time at General Electric, it traversed the country in 2009 when Robert Mathews, founder and president of R. Mathews Optical Works, Inc., located in Poulsbo, WA, acquired the machine from a friend in Massachusetts. Prior to the acquisition he contacted Starrag to ask questions about its origin, capabilities and usefulness in today’s times.
Refurbished and Still Reliable
R. Mathews Optical Works was founded in 1978 with the idea of manufacturing small quantity, specialized optical components. The company quickly became a recognized source for being able to make optics that frequently were out of the box designs and difficult to manufacture. R. Mathews Optical Works continues operating and has established a longstanding tradition and reputation for being able to take a design from prototype to production with consistency and quality for the past four decades.
“At the time, my company was being asked to manufacture larger (up to 12 in. diameter) aspheric lenses and mirrors for the commercial and aerospace industry. Unfortunately, we were unable to measure with any accuracy anything over 8 in.,” Mathews said. “We needed something that we could easily retrofit and get the measurement accuracy that our customers required. Used CMM equipment was somewhat affordable but questionable as to their history and expensive to work on.”
Upon receiving the SIP MP4, Mathews renovated it to get it back into working condition. He soon realized it was worth the time and effort.
“We fitted the spindle with a highprecision Heidenhain electronic probe with a 2.3 in. travel and ran the table through its entire travel in X and Y with an error of less than 0.0008 in. in both directions,” said Mathews. “Further tests found that the original compensated lead screws provided positional accuracy of 0.0008 in. It was then I knew I was onto something with this machine.”
After cleaning, priming, painting and complete lubrication, Mathews’ team ran it through its ultimate test: using a master glass convex spherical surface manufactured and tested interferometrically to 1/4 wave accuracy and 8” in diameter; this was centered on the machine using a precision rotary table. It was then measured on the MP4 in four different positions and found the volumetric error to be 0.0004” - 0.0008”.
In subsequent use on actual customers’ parts, this accuracy enabled them to fabricate the parts close enough in the grinding stage to be able to polish and optically test the components to completion.
“In later years the machine was used less and less so I freed up the frozen spindle and brought the machine back to its original operating condition,” Mathews said, adding, “For all the years that I had the machine and used it for measuring precision optics, it never failed to amaze me the accuracy built into this machine from 1928 using the methods of the time.”
In 2019, instead of discarding the machine, Mathews offered it to Starrag. The SIP MP4, serial number 88, is now home and showcased at Starrag’s North American headquarters in Hebron, KY.
For more information contact: Starrag USA Inc. Skyport Business Park 2379 Progress Drive Hebron, KY 41048 859-534-5201 ussales@starrag.com www.starrag.comGantry Type
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