Reference Mark Selector And Limit Magnet Installation - Renishaw QUANTiC RTLC40 Installation Manual

Reference mark selector and limit magnet installation

IMPORTANT: Allow 24 hours after the scale application before fitting the magnets.
As the readhead passes the reference mark selector magnet or limit switch magnet, a force of up
to 0.2 N is generated between the magnet and the concentrators on the readhead.
• The design of the bracket should be sufficiently stiff so that it is able to tolerate such force
without distorting.
• Fitting the scale and the FASTRACK carrier according to the instructions in this manual
prevents the magnetic force from disturbing the scale.
For accuracy and ease of positioning of the reference mark selector and limit magnets,
the applicator tool should be used.
1. Attach the magnet to the applicator tool as shown.
2. Remove the self-adhesive backing paper from the magnet.
3. Place the magnet in the chosen location, aligned with the outer edges of the FASTRACK
carrier ensuring that it is not mounted on the scale.
• Limit magnets can be positioned at any user defined location along the axis length.
• The reference mark selector magnet should be positioned adjacent to the selected
IN-TRAC reference mark as shown.
1
The reference mark selector magnet is only required for 'Customer selectable reference mark' readheads.
For more information refer to QUANTiC series encoder system data sheet (Renishaw part no. L-9517-9778).
™
20 QUANTiC RTLC40 /FASTRACK
™ ™
Magnet applicator tool
1
incremental linear encoder system
NOTE: The reference mark selector and limit actuator locations are correct for the readhead
orientation shown.
P limit magnet
4. Apply firm finger pressure to the magnet via a clean, dry, lint-free cloth to ensure
complete adhesion
NOTES:
• The limit output is nominally asserted when the readhead limit switch sensor passes the limit
magnet leading edge, but can trigger up to 3 mm before that edge (see
system installation drawing' on page 12).
• The reference and limit magnets may creep when influenced by magnetic materials in close
proximity. In such cases, they should be held in place using an additional fillet of epoxy glue
or similar along the outer edge of the magnet assembly.
• External magnetic fields greater than 6 mT, in the vicinity of the readhead, may cause false
activation of the limit and reference sensors.
Reference mark
selector magnet
Selected IN-TRAC
reference mark
Q limit magnet
'RTLC40 / FASTRACK