CNC routers hold workpieces with vacuum, through sealed fixtures or a porous spoilboard over a plenum, as US patent 6,419,216 (2002) describes, and the US Department of Energy lists clamping, tool powering and spraying among compressed air uses in furniture. Ultra Controlo distributes and services Elmo Rietschle vacuum pumps, which the maker lists for CNC routing and woodworking.
Patents on CNC hold-down systems and the US Department of Energy describe these uses in woodworking, furniture, and lumber and wood.
Vacuum applied inside a soft rubber seal that runs around the edge of the workpiece on a fixture, commonly used for small parts.
A plenum connected to a vacuum pump and closed by a porous spoilboard holds relatively flat workpieces without special fixtures or seals.
US patent 5,987,729 (1999) uses a blower that moves large volumes of air, so that holes the workpiece leaves uncovered affect the hold-down less.
Air piston powering, tool powering, clamping, and controls and actuators, listed by the DOE for furniture.
Spray finishing, listed by the DOE for furniture; the DOE places paint spraying at the instrument air quality level.
Sawing, hoisting, clamping, pressure treatment, and controls and actuators, listed by the DOE for lumber and wood.
Sources: US patents 6,419,216 B1 (2002) and 5,987,729 A (1999); US DOE and Compressed Air Challenge, Improving Compressed Air System Performance: A Sourcebook for Industry, third edition (2016), Table 1.1 and Fact Sheet 1.
The vacuum source depends on how much air the table lets through. Elmo Rietschle and the patent literature describe three options.
Elmo Rietschle lists CNC routing in the woodworking industry for its V-VTN dry running rotary vane pumps, with nominal suction capacities of 17, 27 and 42 m³/h at 50 Hz and a standard ultimate vacuum of 150 mbar (abs.).
Source: Elmo Rietschle, V-VTN page and datasheet D281.
Elmo Rietschle says its oil-lubricated rotary vane pumps use oil to create a seal that enables deeper vacuum levels, and lists woodworking for its V-VCS series.
Source: Elmo Rietschle, oil-lubricated rotary vane and V-VCS pages.
Elmo Rietschle says side channel blowers, also called regenerative blowers, excel at high flow rates and moderate vacuum; US patent 5,987,729 (1999) used a blower so that uncovered holes affect the hold-down less.
Source: Elmo Rietschle, side channel blowers page; US patent 5,987,729 A.
Elmo Rietschle also lists woodworking and furniture production for its claw vacuum pumps, whose compression it describes as contactless and oil-free.
Vacuum pumps from partner brand Elmo Rietschle, which Ultra Controlo distributes and services, and the carbon tower that the Ultra Controlo brochure lists for painting.
Dry running V-VTN and oil-lubricated V-VCS pumps, both listed by the maker for woodworking; the catalogue lists rotary vane pumps in dry or lubricated versions.
Elmo RietschleContactless, oil-free and low maintenance, per the catalogue; the maker lists woodworking and furniture production among their applications.
Elmo RietschleRemoval of oil vapours to below 0.003 mg/m³; the Ultra Controlo brochure lists painting among its uses.
ULTRAKSources: Ultra Controlo Industrial 2026 catalogue, pp. 11 and 19; Ultra Controlo industrial brochure; Elmo Rietschle V-VTN, V-VCS and claw pump pages.
Ultra Controlo is a Portuguese manufacturer of compressed air, vacuum and technical gas systems, with 40 years of experience. We design, assemble and test our own compressors, dryers and carbon towers in Portugal, and supply and service five partner brands.
ULTRASCREW compressors, ULTRASEC and ULTRADRY dryers and ULTRAK activated carbon towers.
Gardner Denver, Elmo Rietschle, Thomas, Speck Pumpen (Circutec) and Speck Triplex.
Preventive and corrective maintenance, original spare parts and emergency support, by our own team.
Source: Ultra Controlo Industrial 2026 catalogue, pp. 3, 10, 16, 17 and 22.
In its background, US patent 6,419,216 (2002) describes two vacuum hold-down systems: fixtures with a soft rubber seal around each workpiece, commonly used for small parts, and universal tables, a plenum closed by a porous spoilboard, for relatively flat workpieces.
US patent 5,987,729 (1999) uses a blower that moves relatively large volumes of air, instead of a pump designed primarily to create a positive vacuum, so that the hold-down is less affected by holes the workpiece leaves uncovered.
The US Department of Energy sourcebook (2016) lists air piston powering, tool powering, clamping, spraying, and controls and actuators in furniture, and sawing, hoisting, clamping, pressure treatment, and controls and actuators in lumber and wood.
The DOE sourcebook (2016) says a dedicated vacuum pump or a central vacuum system provides more suction force at a fraction of the cost of vacuum produced by compressed air, and that venturi generators can cost as much as five times more to operate, except for very intermittent use, below a 30 percent load factor.
The DOE sourcebook (2016) places paint spraying and powder coating at the instrument air level, between plant air and process air, and says quality comes from filtering and drying equipment; the higher the quality, the more the air costs.
The machines, the size of the router tables and the vacuum they need, and the air demand of the shop. We reply with the equipment that fits.
