7
• If a seal needs to be cut it is good practice to make
the seal 3 mm (1/8") longer than required, as the rubber
will readily compress.
• If you need to cut a seal ensure that the ends to be
joined are cut square. There should be no frayed edge
to allow loss of vacuum. To achieve this type of cut use
a sharp chisel and cut in one pass preferably using a
mallet on the chisel.
It is best to put the ends together in the clamp before
pressing the remainder of the seal in. The join of the seal
should always be supported on both sides. (Fig. 4)
Always include the suction hole in any shape to be made.
Extra seal kits are available as accessory.
7. CLEANING THE SUCTION HOLE FROM DUST
OR PARTICLES
Even though most dust particles will not affect the clamp,
sometimes the clamp may become blocked. Simply follow
these instructions to unblock
1. Clear excess dust and particles from the work surface
of the clamp by blowing or sweeping.
2. Reduce air supply pressure to approx 2.7 bar.
3. Locate the air exhaust on the side of the clamp, (when
it is working you can feel the air coming out).
4. With the air switched on hold your finger B (Fig.
5) tightly over the exhaust and block the airflow. DO
NOT PUT YOUR FACE OVER THE CLAMP WHILST DOING
THIS, IT MAY BE HAZARDOUS. DUST WILL FLY INTO
YOUR FACE.
5. Airflow is reversed and will now come out of the
suction hole.
6. Dust and particles will be ejected from the suction
hole.
7. You may need to repeat this procedure a couple of
times to completely unblock the suction hole.
8. Remember to blow or sweep off the excess dust.
9. The unit should be ready for working.
8. IRREGULAR, SMALL SHAPES
The unit can hold small and irregular shaped work
pieces by moving the seal into the work grooves of the
clamp that best suits the shape required by using the
different sized seal.
If the seal may need to be cut to fit the size of the work
piece. It is better to cut it 3 mm longer (1/8") than is
exactly required, as the rubber will compress readily
(Fig. 3 and 4).
9. SMALL WORK PIECES
The (Fig. 6) shows a small piece of material being worked
safely. Despite the small dimensions (the piece measures
only 100 x 200 mm) it remains on place and does not
move even with a high power plunge router.
Note that the clamp has a rated holding power of 800
gr/cm
2
, so a large area is held with greater force than
a small area.
Use the largest possible holding surface under the
workpiece.
10. LARGE WORK PIECES
Larger work pieces of up to 1 m
2
can be held by just one
unit, but the work piece will need to be supported at
its extremities, as the lever action may cause the work
piece to lift off the clamp (Fig. 7).
Very large work pieces will need to be held by 2 or
more clamps.
By using more than one clamp the margin of safety is
increased particularly if using timber. Knotholes may
cause loss of suction in a particular clamp but the
other clamps holding the large work piece may provide
adequate holding power.
11. INTENDED FUNCTION
The SVN250 unit is designed to hold any flat non-
porous material without damaging delicate surfaces.
Although it can, the unit is not intended for use as a
lifting device.
This product is not intended for use on moving or
dynamic items.
If the work piece is drilled or cut through where the
holding vacuum has been created, this will cause loss
of holding instantly.
The unit is not designed to hold tall items
12. CLEANING
The unit requires no special cleaning. Air dusting is all
that is usually required.
Do not use solvents.
Internal parts of the clamp will be adversely affected by
dust and particles. Ensure all incoming air is free from
dust and particles, as this will reduce the performance
significantly.
13. USEFUL NOTES
For any given application use the largest possible holding
area. More area gives greater holding power.
The air supply line is transparent to allow monitoring
of the quality of the air supply. Dust and oil in the air
supply will reduce the performance of the unit and
ultimately cause its demise.
Although it is possible to use just one square of the
clamp we do not recommend it, particularly for routing
works.
The holding power of the unit is rated at 800 gr/cm
2
. So
more surface area equals more holding power
MDF panels are porous and will not give a stable work-
piece. Painted MDF works very well
Cracks, knots and pinholes will allow air to flow through a
piece of wood causing greatly reduced holding power. Small
