Optical comparators are devices that are used to inspect manufactured parts through the application of the principles of optics. Optical comparators have been in use for nearly half a century and even though some elements have changed, the basic principles of how they work have remained the same. Optical comparators magnify a part on a screen, allowing for the part’s dimensions to be compared to set limits. To be able to do this, it is important for the quality control operators can hold a part horizontally so the optical comparator can scan and project the part. This is where V-blocks come into use.
How V-Blocks Work
V-blocks are used in precision metal work to hold rounded parts in place so certain processes such as inspection, drilling or milling can be done on the part. V-blocks consists of a steel or iron base with a V-shaped channel carved out on the top. This V-shaped channel is where the metal part goes into. Typically, the V-block will also include a clamp that holds the part firmly in place. There are many variations of V-blocks and some even come with internal magnets to keep the metal parts firmly in place.
Place Part in V-Channel
To begin the process of working on a part that is held horizontally on a V-block, start by placing the part on the V-block. Once this is done, turn the thread of the clamp until it touches the part that you want to work on. Once you have the part exactly where you want it, tighten the thread slightly in order to hold it firmly in place. In the event that you are working with a part that is long, you might have to use two V-blocks to hold the part in place.
Place V-Block and Part on Optical Comparator
Once your part is securely attached to the V-block, you are ready to move to the next step which is to install it on the optical comparator. Optical comparators feature a tray (also known as a stage) where the V-block can be held securely in place. Once this is done, you are ready to begin the process of quality control on the part with the horizontal optical comparator.
Things to Note
The condition of the V-bloc can significantly affect the accuracy of the measurements that you take, thus it is wise to inspect the V-block before you secure any part on it. One of the things you should be on the lookout for is rust which can corrode and affect the overall performance of the V-block. In addition, the threads of the clamp might affect its ability to secure the part firmly. You should check to see (and feel with your fingers) for any dents or scratches that may make it hard for the block to secure firmly on the optical comparator’s tray. Finally, ensure that you always store your V-blocks in the case that they came with to avoid damage.
V-Blocks are useful for holding workpieces firmly in place when doing quality control work with a horizontal optical comparator.