Following USAF retirement, Frank attended Brevard Community College where he attained an Associate of Science degree in Bio Engineering and was immediately hired by the then Holmes Regional Medical center in Melbourne as a medical equipment technician. He worked there for 10 years progressing to the Director of the BioMedical department with prime duties in the Radiology Department. Because of his experience with maintaining the cancer radiation treatment machine (a linear accelerator) he was offered a position with Varian Associates Medical Division in Palo Alto, California. He completed his BioMedical training with Varian through courses from Stanford University. He worked for Varian installing the Accelerators at various medical facilities around the United States and Japan. Frank retired from the work force in 1998.
Eventually, flour mills overtook sawmills as a dominant industry at the falls. In 1860, flour production stood at 30,000 barrels ; it reached 256,100 barrels in 1869. By 1874, Charles A. Pillsbury and Company owned five mills at the falls, and in 1879, Washburn-Crosby Company (now General Mills ) owned four mills. The former Washburn "A" Mill building on the west side of the falls exploded on May 2, 1878, but its owners quickly rebuilt the west side district, including a new, larger Washburn "A" Mill . Meanwhile, in 1880, Pillsbury began building the huge Pillsbury "A" Mill on the east side of the falls. It had a capacity of 4,000 barrels per day when it first opened.  Improvements in milling technology made it possible to grind the tougher spring wheat into a finer product, producing Minnesota "patent" flour, the finest bread flour in the world at that time. By 1900, Minneapolis was grinding percent of the world's grain.