THORLABS Vytran LDC401, User Manual

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LDC401 & LDC401A Automated Cleavers Chapter 7: Cleaving
Rev B, July 19, 2017 Page 13
Figure 12 Lifting Levers and Thumb Screws
Thumbscrews on the FHB lids provide added clamping force for large diameter fibers (>400 µm) or for fibers with
very slippery coatings requiring additional clamping force. If the thumbscrews are not required, they may be kept
out of the way by threading them backwards into the lids or by removing them completely.
Note that when the thumbscrews are used, the user should be sure that they are undone when operating the lifting
levers to open the FHB Lid.
Also note that thumbscrews are not a substitute for correctly chosen and fitted FHB inserts!
The normal clamping force created by the magnets may be excessive for some applications involving very delicate
fiber (e.g. thin-walled capillary tubes and PCF). If the lids crush the fibers, it will be necessary to reduce the clamping
force. This can be achieved by pushing out the magnets in the lids with a stick, or pulling them out with a rare-earth
magnet. It is prudent to mark one side of the magnets before removal so the orientation and position are easily
identified. After completing work on the delicate fiber, remember to return the magnets to the lid holes facing the
correct direction. They should all be attracted to, not repelled by, their counterparts in the FHB body. The polarity
of these magnets alternates, and can most easily be determined by a rod-shaped magnet that is easy to hold
between two fingers.
7.4. Stripping the Fiber
The fiber end should be stripped down to the cladding over a sufficient length to allow for the desired post cleave
length plus the discard length. The discard length should ideally allow for full clamping in the FHB, and should
therefore be 1.8
″ (45 mm). A Ruler Block is provided for accurate positioning of the strip interface relative to the
cleave point. The fiber must be stripped down to bare glass and thoroughly cleaned at the location where the
diamond blade strikes the fiber (the cleave point).
Figure 13 Stripping Fiber using a Miller Stripper
Thumbscrews
Lift levers to permit
lids to close fully