Dear Search Engineer: We need an automated deburring process. The product is a steel forging and the area to deburr is a two-inch diameter broached hexagon. The burr is left after the breakthrough with the final progressive broach. Current quotes we obtained for hydro deburring are too expensive. Steel brushes that hit the area during the movement of the parts by the gantry are in constant need of adjustment— either they are too far away to contact the burrs or too close and remove too much of the coating. —J.S. in KY
Dear J.S.: You may want to consider a thermal deburring process, such as offered by the Surftran Company at www.surftran.com. They produce a thermal deburring machine that is used to remove exactly the type of burrs you describe. The critical factor for the operation is the surface-area-to-volume ratio of the parts to be deburred, which you didn't mention. There is also the electrochemical technique for burr removal, such as Burlytic, which can be found at www.kmech.net/about..html. Good Luck.
Dear Search Engineer: I'm looking for a clear, breathable film material with a permanent pressure sensitive adhesive on the back. Any ideas where I can find it? —D.D. in NY
Dear D.D.: There is such a film available in the medical industry known as bio-occlusive bandages. If you are prototyping, this material may be a useful place to start.
Dear Search Engineer: I need some basic information about dc to ac power inverters in the 2,500-4,000 watt range as they apply to the boating industry. Where can I find this kind of information? —J. C. in MD
Dear J.C.: You might check NFPA 303-2000 and with the American Boat and Yacht Council at www.abyc.com. Another source is Behlman Electronics at www.behlman.com.
Dear Search Engineer: I'm having problems locating vendors who furnish injection molded plastic tooling made from spray metal. This is to make plastic parts in 500-1,000 piece lots. —B.J. in CA
Dear B.J.: After a little research, we came up with quite a few different suggestions, and here they are:
Since there are inherent limitations making the spray metal process useful for very simple parts, consider alternative processes since many vendors have moved away from spray metal with the advent of solid modeling and CNC mold making.
Consider aluminum or Kirksite tooling for short run items in the 100-800 piece annual quantity range. Side details can be incorporated and you don't have the 50 inch2
limitation of spray mold construction. Try Protomold, which makes the tooling and supplies the injection molded parts in as little as 5 working days. They do have a size limitation on the parts, www.protomold.com.
Finally, look at the RIM process—www.rimnylon.com.