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needle to reverse polarity. With the compass
facing you along the plane of the roof, move
the Compass block from side to side and up
and down the roof slope until the needle is
attracted by the field produced by the Magnet
blocks below. In two-person operation, tapping
on the roof deck may help identify the location
from the other side. Continually adjust the tilt
angle of the Compass block so that the needle
rotates freely. Center the Compass block over
the place where the magnetic field's effect on the compass needle can be seen
most clearly. If necessary, have the Magnet blocks relocated along length of
rafter until they are as near as possible to the target location.
Figure 5. Red compass needle down = center
Coordination for locating a series of attachment points
-In the area where a series of attachment points will be located, make an
approximate layout, including selecting which rafters will be used.
-Measure the desired distance from ridge or eave to each point.
-Agree on a sequence for locating attachment points.
-From below, identify the rafter for the first attachment point, measure
from ridge or eave and place clamp at desired location.
-If direct verbal communication is not possible, use hands-free mobile
communication or a system of knocking on the roof deck to confirm
when to move from one location to the next.
Figure 4. Compass block
Key in on rafter center until
the north-pointing
(red)
of the needle points straight
down (Fig. 5). Move in and
out of apparent center sev-
eral times and continue ad-
justing the Compass block's
tilt angle to confirm that the
needle is moving freely.
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Storage and Maintenance
The RE1 is designed for years of maintenance-free use. However, certain care
measures will help ensure long, safe and trouble-free service.
Keep magnets below 80°C (176°F) at all times. Magnets allowed to reach this
temperature may lose a portion of their magnetic strength. Since working envi-
ronments may include direct sunlight and hot surfaces, when not in use, store in
the shade and not in an enclosed space that may get too hot.
Using a slightly damp cloth or paper towel, remove any iron-containing mate-
rial that may collect on the magnet blocks. Be especially attentive to this before
clamping the blocks to finely finished surfaces, such as exposed rafters. Keep
storage surfaces free of loose ferrous items and debris like screws or iron filings
that may be attracted to the magnets.
Keep all parts in a dry location. Do not submerge or expose to wet conditions.
end
Store the compass at least 12" apart from the magnet blocks and laying flat in
the same plane. This will maintain a weak or neutral magnetic field at the com-
pass, protecting the magnetic properties of the compass needle.
How to restore compass polarity
If the white end of the compass needle is attracted to magnetic north (between
the Magnet blocks) instead of the red end, its polarity has reversed. This hap-
pens under conditions of normal use. To reestablish correct polarity:
1. Lay the Compass block face up on the edge of a flat, stable surface.
2. Remove one of the magnet blocks from the clamp. Identify the location of
the magnet within the Magnet block. With its large, flat side down and the
clamp rotation hole up, starting from above, gradually bring the Magnet block
down, with the magnet directly over the red end of the compass needle, until
the Magnet block is in contact with the Compass block.
3. Pull the Magnet block over the side of the Compass block in the direction the
red (north) needle points. As it nears the edge, twist it so that the same side
that faced down now faces the red end of the needle from the side. Slide the
Magnet block down the side of the compass block, then away.
Repeat steps 1-3 two or three times. Test repolarization by returning the Mag-
net block to the clamp and holding the Compass block to simulate operation.
(see also video at raftereye.com)
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