Tag: workholding

When it comes to innovative solutions for industrial applications using compressed air, EXAIR has long been a trusted name, and our Evac vacuum generators are no exception. These compressed air-powered devices are designed to create a powerful vacuum with remarkable efficiency, making them ideal for a wide range of tasks—from pick-and-place operations to bag opening and even vessel evacuation. Whether you’re lifting parts, opening bags, or clamping materials, EXAIR’s E-Vacs offer a versatile, maintenance-free solution that optimizes performance while having ZERO moving parts to wear or breakdown, and let’s be honest, mechanical vacuum pumps are always breaking down. Let’s dive into what makes these vacuum generators stand out and explore some of their key variants.

Our Adjustable E-Vac Vacuum Generators are the ones that typically fall into the “number of other applications” category above. While the In-Line E-Vacs are compact and reliably generate rated vacuum on demand, the Adjustable E-Vacs have some distinct advantages in certain cases:

Larger throat diameter. In-Line E-Vacs have a very tight throat, which generally doesn’t matter if they’re just hooked to Vacuum Cups that’ll be placed on a relatively clean surface. The wider throat of the Adjustable E-Vacs means that they can pass small debris from less-than-pristine surfaces that a Vacuum Cup might lift, or shavings that might fall into a work holding fixture on a machine tool. They can even pass liquids, so they’re sometimes used for small spill cleanup.

Adjustability. It’s right in the name, of course, but it IS a big deal. While you can regulate the supply pressure of almost any compressed air operated device to vary the performance level, you can thread the plug into, or out of, the body of an Adjustable E-Vac to literally put it in a whole new performance band. This is beneficial if you’re picking up, or holding down, pieces of different sizes, shapes, and weights. Just loosen the locking collar, make the adjustment, tighten it back up, and it’s ready for use.

If you have questions regarding our Adjustable E-Vacs, or how to solve any issue with an EXAIR Intelligent Compressed Air® Product, feel free to contact EXAIR . One of our Application Engineers would be pleased to help you determine your best solution.

Jordan Shouse
Application Engineer

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Workholding refers to any method of keeping an object in a fixed position while force is exerted onto it. If you’ve ever put something in a clamp or vise to loosen (or tighten) a bolt or screw into it, you’ve performed workholding. In fact, if you’ve ever wrapped a napkin around a cold bottle of your favorite beverage to get a better grip while twisting the cap off, that’s workholding too.

In manufacturing and machining settings, any number of different clamps, fixtures, jigs, chucks, vises, etc., are commonly used for workholding. For efficiency, the main feature of a good workholding device is an easily repeatable setup that can secure the piece quickly, and release it just as quickly. The table of a milling machine, for example, will commonly have t-handle clamps for this.

In addition to mechanically clamping parts, they can also be held in place with vacuum. The basic principle is kind of like an air hockey table, but in reverse: instead of floating the puck on a thin curtain of air being blown out of the holes on the table, it’d be held in place by pulling air back through the holes, to draw a vacuum between the top of the table and the bottom of the puck. Vacuum pump systems can be used for this, but they can get pricey if you don’t already have one (with enough extra capacity) to tie in to. Those pumps have moving parts, so they’re going to need maintenance from time to time as well.

EXAIR E-Vac Vacuum Generators, on the other hand, don’t have any moving parts to wear or electric motors to burn out. They’re compact, they draw rated vacuum as soon as you start supplying compressed air to them, and they drop that vacuum off just as soon as you turn the air off.

For most common workholding applications, we’ll specify an Adjustable E-Vac, for a couple of reasons:

• Because they’re adjustable, you can quickly dial in different vacuum – and vacuum flow – levels needed to hold parts of different sizes, shapes, and/or weights.
• They have a large enough throat diameter to pass small amounts of chips or coolant, so the part doesn’t have to be perfectly clean when you place it in the fixture.

Of course, not EVERY application is a COMMON one…case in point, I had the pleasure of helping a caller from a tool & die company the other day, who wanted to make a fixture to hold a metal block in a V-shaped fixture with two flat surfaces that correspond to the two flat surfaces of the block that won’t be worked on. The idea was to put several holes in each surface, with shallow countersinks for o-rings, so that when the block was set, the o-rings would make a positive seal, and pull vacuum on those holes with an E-Vac. Since there’s a tight seal between the blocks & fixture, and the blocks will be clean & dry, this doesn’t require the chip/coolant passage of an Adjustable E-Vac. And since the cutting & drilling will exert a good amount of force, in several directions, we DO want a high vacuum level to make sure it doesn’t move. At all. No matter what.

For this application, we specified a Model 810023M In-Line High Vacuum E-Vac. It’ll generate 27″Hg worth of vacuum, and in case of any minuscule movement or misalignment of the block, it’ll provide an impressive 2.67 SCFM worth of vacuum flow (to overcome any leakage past the o-rings) and still hold the block in place with 24″Hg.

If you’d like to find out more about EXAIR Vacuum Generators for workholding, pick-and-place material handling, vacuum forming/filling/pressing, or any other application where you need any more than a few inches of mercury worth of vacuum, give me a call.

Russ Bowman, CCASS

Application Engineer
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