3, 2, 1, Contact - Measuring Thickness Thickness is one of the most frequently measured dimensions, and also one that is very easy to understand. So you might think that someone would come up with a one-style-fits-all measurement approach good for just about every kind of thickness application, but it just isn’t so.
An Inside Look At Special Diameters Sometimes we are faced with making critical inside diameter checks on parts that do not present themselves in a straight forward fashion. Usually these checks are on the inside of some type of bearing and they can be almost any size.
Bar Talk: What's Your Sine? A few months ago this column described the use of surface plates, observing that a flat surface is the basis for most dimensional measurements. Many workpieces, of course, are neither flat nor straight. In order to measure the angular accuracy or straightness of an angled surface using a surface plate, a sine instrument comes into play.
Beyond the Height Gage and Surface Plate For many years now, the method of choice for low-volume, general purpose inspection has been surface plate work using test indicators and height gages. Recently, electronic height gages have made the layout inspection process a little more accurate.
Can't Measure it? Try a Caliper Gage If a workpiece has ever left your shop with an important dimension unmeasured because you couldn't get at it to measure it, you probably didn't know about indicating caliper gages.
Depth Gages Depth gages are among the simplest of indicator gages, typically consisting of an indicating device mounted through a reference bar or plate. Though they may be simple, depth gages are used in thousands of critical applications, to measure the depth of holes, counterbores, slots, and recesses, as well as heights or locations of some features.
Gage Layout Is Up To the User In this column we have discussed how most dimensional gaging applications are really just variations on four basic themes, to measure height, depth, thickness, or diameter.
Gaging Distance Between Hole Centers Many of the gaging applications we've considered over the years involve size inspection of a single feature, e.g., the diameter of a hole, depth of a groove, height of a gage block, etc. Many parts, however, contain multiple features that establish dimensional relationships between two or more other parts.
Gaging the "Oddball" Application Virtually all metalworking shops need to measure holes, thicknesses, and heights. Some shops, however, have to perform measurements that are more limited in application: some are industry or even company specific.
Giving Your Gage More Intelligence for Less Like phones and computers, today's bench amplifiers offer greatly improved performance, better displays, less power consumption and more data user capabilities. But what struck me in reviewing that old column was that most of the functions we were touting for amplifiers then are now available in digital indicators.
Got a Match? Producing precision spools and sleeves (e.g., for fluid pumps) and other pairs of parts with matching inside and outside diameters can be among the trickiest of quality issues.
Harmonic Analysis By using harmonic analysis you can figure out what creates the lobing conditions on the part. There are three major contributors to the lobing condition.
Improving Height Gage Results As with any measurement, the quality of the result depends on the measurement instrument and the care with which the operator handles the measurement procedure.
Locking It In With A Good Taper Fit A machined taper fit between mating parts is a fast and secure way to put two parts together. Fast mating and good alignment make taper fits critical in two very different fields. One that most machinists are familiar with is the taper fit that aligns the tool holder and spindle on a machining center.
Scribing for New Heights The need for long range height measurements has been around since the principles of layout work became a fundamental requirement in machine shops.
“SQUEEZE” GAGING Machinists working strictly in metal-working shops do not have many occasions to gage the thickness of soft materials. But many of our readers work in supporting roles, helping to build or maintain the machines that produce textiles, plastic films, paper and other products that are compressible.
Temperature Compensation Temperature variation is one of the most significant sources of gaging error. As manufacturing tolerances get tighter and the margin for gaging error gets smaller, it becomes an issue that must be addressed.
The Gaging Environment: Degrees of Control The environment is often the largest contributor to measurement errors. Conversely, once the environment is under control, great strides can be made in improving the overall measurement process.
The Long and Short on Depth Gages Depth gages are among the simplest of indicator gages, typically consisting of a short range indicating device mounted through a reference bar or plate. Though they may be simple, depth gages are used in thousands of critical applications to measure the depth of holes, counterbores, slots, and recesses, as well as heights or locations of some features.
The Nuts And Bolts Of Thread Gaging No pun intended, but thread gaging has always seemed a rather convoluted subject to me. So, when I was questioned on the topic recently, I asked my friend, Lowell Johnson, a recognized authority and president of the Johnson Gage Company, to explain some of the basics and offer some tips on the process.
The Plane Truth About Flatness The flatness of machined planar surfaces is often critical to the performance of parts and assemblies. The plane is also the basis or reference for most dimensional and geometric measurements; including height, location of features, squareness, and datum’s.
When Gaging Becomes Measuring That Becomes Gaging Many articles ago we discussed the terms "gaging" and "measuring," which are often used interchangeability. There are times when gaging is appropriate and others when measuring is the best way to go.
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