Belt sander

Figure 10.32 A photograph of a belt sander used to perform the final finish of the channels. The side guard has been temporarily removed to show the sanding belt (courtesy of Jeffrey A. Kuhman of Glycon Corporation)...

Fig. 9-5 Back-reflection pinhole patterns of coarse-grained recrystallized copper. Unfiltered copper radiation (a) from surface ground on a belt sander (b) after removal of 0.003 in. (75 //m) from this surface by etching.

Must be able to use conventional electronic troubleshooting instruments such as multimeters, function generators, oscillators, and oscilloscopes. Should be able to use conventional machine shop equipment such as drill presses, grinders, belt sanders, brakes, and standard hand tools. 

Wide-belt sander A machine using the principle of a contact roll backup for a wide abrasive belt. 

Make sure safety switches requiring momentary contact for on-off control are in working order and not over-ridden on the tools they should be on (such as drills, tappers, fastener drivers, horizontal, vertical and angle grinders with wheels larger than two inches in diameter, disc Sanders, belt sanders, reciprocating saws, saber saws, and other similar equipment). 

The semipositive mold serves a wide variety of applications. It is especially desirable for parts requiring a long draw, for parts that have a heavy section at the bottom of a deep piece, and for parts that must combine heavy and thin sections. This mold tends to produce a better surface finish on medium-impact materials because of their higher density, and also because the greater pressure forces the resin to the surface. Another advantage of the semipositive mold is that it produces a vertical flash line that may be removed easily by finishing on a belt sander. 

When the diameter/thickness conditions are not met, it is necessary to fill the holes using a separate process. A screening process does this from one side of the panel with polyester screen with an oversized hole pattern. After hole filling and curing the resin completely, the fabricator removes excess resin using a belt sander ( 600 to 800) or a ceramic brush. Figure 22.16 illustrates the process.This is a tricky but necessary operation for microvia board makers, particularly for photovia processing. 

I use a belt sander to clean the sides of the bar and to remove any burrs there <5). Sand evenly over the entire surface. If you don t have a belt sander, use a flat file. 

You ll need a hacksaw,.a drill press with drills up to /i in., a belt sander, l/4-in. and %-in. laps, and an electric welder (though brazing can be substituted for welding if you prefer). 

Do not use a belt-sander, propane torch, heat gun, dry scraper, or dry sandpaper to remove lead-based paint. These actions create large amounts of lead dust and fumes. Lead dust can remain in your home long after the work is done. 

Stainless steel wire brushing or light grinding with clean aluminum oxide abrasive disks or flapper wheels are helpful. Grinding or polishing with grinding wheels or continuous belt sanders tend to overheat the surface layers to the point where resistance cannot be fully restored even with subsequent pickling. Brief descriptions of hot- rolled, cold-rolled, and mechanical finishes are presented in Table 8.34. 

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