Solving this problem with a microprocessor ten years ago might have cost thousands of dollars and an MA in electrical engineering but, today, a short trip to Radio Shack, Goodwill, and Lowe's nets just about everything you will need. A programmed Arduino microprocessor is the brain, transforming a household vacuum cleaner into an efficient mixer for your vat. The Arduino was invented with the arts in mind. The hardware and open-source software (free online) are not proprietary so you can do with it as you wish without copyright infringement. Cost? Thirty-four dollars! Total outlay depends upon what you pay for a used vacuum cleaner, but a hundred dollars is a reasonable estimate. Typically, the system looks like this: A motion sensor detects my hand reaching for a felt (stored under the vat), sending a positive voltage to the Arduino pin which is programmed to turn the vacuum on for eight seconds via a 110-volt relay. The hose extends from the machine's exhaust to a PVC pipe secured to the bottom of the vat where the pressure is released. A rheostat enables fine adjustment. Aside from the 5-volt motion detector, all hardware is six feet from the vat in an elevated plastic container, avoiding any danger of AC voltage. \[The author offers detailed schematics and programming code for download. Please contact him via email at ifugaopapercraft@ gmail.com. Ed.\] After couching, you return to the vat ready to pull another sheet without ever stopping for a minute to mix. Even a subjective measure of time and labor necessary to mix the vat by hand would reveal considerable effort. Possibly the most significant benefit of the system is a perfectly mixed vat. From start to finish, you will be confident that the pulp is homogenously suspended throughout the vat.

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