Vacuum Clamping System Multi-Clamp

An efficient, flexible clamping system for the small production shop


Vacuum Clamping System Multi-Clamp

If you have an air compressor or vacuum pump in your workshop, then you've got half of what you need for an effective vacuum clamping system. Schmalz, a world leader in vacuum clamping systems for industrial and commercial applications also has a vacuum work holding system that is designed for manual work in a small shop environment. 'Vacuum clamping' in this context refers to a method of holding work firmly in place by means of compressed air, rather than clamping stock together, as is done with vacuum pressing.
Schmalz's Vacuum Clamping Multi-Clamp system is available in two versions. The version I tested (VC-M) has an integrated pneumatic ejector, and is used with an air compressor. The second version (VC-MV) is configured to work with a vacuum pump. Both systems use air suction to hold stock firmly in place.
After using the VC-M Multi-Clamp in the shop over a six week period, I can identify the following advantages of vacuum clamping over conventional work holding.
  • Vacuum clamping works exceptionally fast. Discounting the time involved in initial start-up of the air compressor, it takes no more than four or five seconds to secure a work piece onto the Multi-Clamp.
  • There is absolutely no marring of the work piece. You can clamp painted, varnished or lacquered work without damaging the finish.
  • You can rotate the work piece a full 360° without having to unclamp and reposition the piece.
  • You can swivel the work piece 90° forward for unrestricted access to the top of the piece.
  • It's very portable, and can be easily moved to a job site (or anywhere you have access to an air compressor).
The Multi-Clamp does require that you have an air compressor or vacuum pump. I tested it with a 2-gallon 2.6 SCFM twin-tank compressor, and a 20-gallon 6 SCFM compressor. Either compressor can generate sufficient air pressure for the Multi-Clamp to function properly, but the larger the air tank, the less frequently the compressor motor will recycle.
The VC-M kit that I tested consists of a multi-base, a vacuum plate, shutoff valve with NPT plug, an inlet valve, 39" of flex hose, 24" of spare sealing cord, and an instruction manual.

Suction plate: (A) suction hole; (B) cord grid; (C) friction pads; (D) sealing cord; (E) air hose inlet; (F) mounting holes  
The suction plate measures approximately 1-3/8" x6-3/8" x 6-3/8", providing a fairly large suction area. In the middle of the plate, on the top side, is a small hole (A) through which air is extracted. Air enters the plate through an inlet (E) on its side.
A sealing cord (D) runs along the outside of the suction plate - it compensates for irregularities in the work piece surface, and helps attain optimal suction. The cord can be repositioned along any of the grid channels (B) to accommodate smaller stock sizes. On the four corners of the plate are friction pads (C) that help to keep the work piece from shifting about.
The suction plate, which you can purchase separately from Schmalz, can be used as a stand alone clamp. Mounting holes (F) enable you to secure the plate to a work table.
Along with this rectangular plate, there are optional round and oval plates.

Suction plate connector ring       
On the bottom of the suction plate is a connector ring that fits onto a connector arm on the multi-base. You'll also notice a sealing cord on the bottom - this compensates for irregularities in the work bench surface when the plate is used as a stand alone clamp.

Multi-base: (A) mounting holes; (B) suction plate connector arm (C) clamp handle; (D) compression fitting; (E) connector to plate inlet; (F) rotating lock arm; (G) swivel lock arm          
The multi-base measures 8-1/2" x 6-1/2" x 6-3/4" and weighs almost 9-1/2 pounds. It's made of 1/8" thick sheet metal and cast aluminum. Four mounting holes (A) at the base enable you to secure the multi-base to a work bench, or, as I did, to a piece of plywood, which can then be clamped to any work surface. This makes the unit easier to move around, or store when not in use.
On the top of the multi-base is a connector arm (B) that is inserted into the connector ring on the bottom of the suction plate. Once installed, a locking clamp (C) firmly clamps the two pieces together.
Air from the compressor enters the pneumatic ejector through an inlet just below the suction plate connector arm via a compression fitting (D). Behind the pneumatic ejector is an inlet (E) that is connected to the inlet on the side of the suction plate by means on a short length of plastic tubing.
The multi-base can rotates 360° by releasing the rotating lock arm (F) and it can swivel 90° forward by unlocking the swivel locking arm (G).

Suction plate and multi-base configured for use with air compressor        
Once the suction plate is mounted onto the top of the multi-base, you connect a short hose from the multi-base to the plate, and then connect the longer hose from the multi-base to the air compressor hose via the NPT plug. Compression fittings make it easy and quick to attach the hoses.

Use the suction plate independently
Suction plate mounted on multi-base
I was very impressed at how quick and easy it was to set up the VC-M. When working on small flat work pieces I found it just as convenient to use the suction plate alone. It saves a bit of time not having to clamp the multi-base to the work table. For larger pieces, or when I need to turn a piece around to access the back or one of the sides, it's best to mount the plate on the multi-base.

Support large work pieces on the multi-base
Work pieces can be rotated a full 360°
I really like the versatility that the multi-base offers, in being able to both rotate and tilt the work piece for easy access to all sides, as well as the top. To access the bottom you would, of course, need to turn the work piece upside down. The heaviest piece I used on the VC-M was about 30 pounds.
With the VC-M you can easily freehand rout work pieces that would otherwise be somewhat difficult to clamp in a more conventional fashion. I also found that it worked great for holding stock while applying a finish. I think that it would also work exceptionally well for carvers and sculptors who need to constantly turn and tilt their work piece.

Swivel a work piece up to 90°
The VC-M: practical and functional
While I tried the VC-M with a small 2-gallon, 2.6 SCFM twin-tank compressor, I found that the compressor motor was running almost continuously in order to replenish the air in the tanks. You should also remember that small, portable compressors typically have a duty-cycle of no more than 50%, which means that the compressor pump shouldn't run more than 30 minutes out of every hour.
On a larger 20-gallon 6 SCFM compressor, with the regulated pressure set to about 25 PSI, the motor recycles about every 4 minutes. For intermittent use, this isn't too bad. However, for more continuous use, you'll want a larger, stationary compressor with a 60 to 80-gallon tank and an 80% or higher duty cycle.
Pricing on the VC-M varies depending on the options that you need. It can range from as low as $150 for a simple clamping solution based on the suction plate, to much higher for a complete system with a portable vacuum pump.
For a small production shop, the Vacuum Clamping System Multi-Clamp (VC-M) provides an efficient, flexible way to hold stock. It's an exceptionally well made accessory that has excellent holding power.



  • Suction plate: 1-3/8" x6-3/8" x 6-3/8"
  • Multi-base: 8-1/2" x 6-1/2" x 6-3/4"
  • 8-7/8" H (to top of suction plate)
  • Sealing cord can be configured for various work piece sizes
  • Multi-base rotates 360° and swivels 90°
  • Suction plate: High impact ABS plastic
  • Multi-base: Metal body/aluminum clamping head
  • Suction plate: 1.2 pounds
  • Multi-base: 9.4 pounds
  • Includes: multi-base, suction plate, shutoff valve with NPT plug and compression fitting, 39" of flex hose, 90° swivel compression fitting, 24" spare sealing cord, instruction manual

PRICE:$799 as shown
MADE IN:Germany
SOURCE:Call: 919-865-0624
Email: Mason Nicholson
Carl Duguay, February 2013
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