Parts manufacturing starts with a piece of raw material and then removing stock by machining until the final part geometry is reached. There are many methods to hold parts, including mechanical fixtures with clamps and screws, using a vise, or even tape! Today we will explore the benefits of workholding using a vacuum chuck. A properly designed vacuum chuck can satisfy many part fixturing requirements, and offers several advantages over other methods:
1. Ability to Hold Non-ferrous Materials Easily
When making steel parts from a plate, one of the easiest and quickest methods of holding the part is a magnetic chuck. The magnet provides the vertical holding force to secure the part material while cutting. However, if you need to cut a part made from a non-ferrous material such as aluminum, brass, titanium, plastic or a composite, you must utilize another approach. The vacuum method is not picky when it comes to part material.
Material loading and unloading on a fixture that uses clamps and screws is time consuming. Between each part cycle, a finished part must be removed and a new piece of raw stock fastened to the fixture. Mechanical clamps must be loosened or screws removed. This requires tools and operator time. Even in the case where a quick-clamp is used, operator time is still needed. In many cases, the fixture must be cleaned (more time!) before a new part blank can be loaded. A vacuum chuck provides a much quicker change from finished part to blank. The vacuum is switched off, releasing the part. A new piece of material is placed in position. The vacuum is turned back on, and the part is now securely clamped and ready to be cut. Viola!
A fixture using mechanical clamps will typically block the optimal cutting path. For example, most parts made from plate require that the complete periphery be cut. Holding clamps generally block this path. So, to completely finish the part, it will be necessary to do some cutting, move the clamps, and recut those areas that were blocked. Or, use another part setup with different clamp locations to complete the cutting. This adds to cycle time significantly, reduces overall part accuracy and increases the part cost. A well designed vacuum chuck, using no external clamps, exposes the complete part for a single-setup cut with nothing blocking the cutter path.
4. Higher Accuracy
A vacuum chuck locates the part against the chuck surface. For applications that require high accuracy, the surface of the vacuum chuck can be manufactured to a high degree of precision by grinding. This is possible to micron levels. This creates a very accurate and qualified location surface for the part, which in turn results in a precise finished part. And, for X and Y axis location, pins can be installed to orient the part prior to cutting.
5. More Parts Per Hour
Most parts are made one at the time. If, however, your production requires a quantity of identical parts be made, vacuum chucks can allow you to produce multiple parts in a single setup. The chuck can be designed to nest multiple parts, using a single piece of material. This is far more efficient than producing parts individually, assuming your machine has the capacity.
6. Decreased Material Waste
Many large aluminum aircraft parts produced with traditional clamping methods require an over-sized (200%) piece of raw material. Why? The extra material is required for clamping space. The actual part lies inside those dimensions. Imagine how much material is wasted! A vacuum fixture does not use external clamps, and significantly reduces the part material size and waste. This means a lower priced part, and likely more profit for you in the long run.
Learn more about our vacuum workholding systems.