Xerox WC5545F, Service Manual

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August 2007
6-18
WorkCentre 5687 Family
GP 6
General Procedures & Information
GP 6 Screw Usage
Purpose
To prevent damage to parts that may be damaged by screws not being installed correctly.
Procedure
Replacing Existing Screws
Always use the correct driver for the type of screw head. Use a nut driver if possible; this gives
a better grip than a slotted or cross-head driver.
Take care not to install self-tapping screws into machine-screw holes, or machine-screws into
self-tapper holes.
When replacing self-tapping screws into plastic components, turn the screw counterclockwise
to engage the original thread, then turn the screw clockwise. Do not overtighten. If a new
thread is cut, the plastic component will lose the ability to hold the screw as firmly, and eventu-
ally not at all. This also applies, to a lesser degree, to metal components.
NOTE: Reverse the direction of turn for left-hand threads.
Use the same method for machine thread screws and nuts to avoid cross threading.
Inserting a Screw into an Un-threaded Hole
Some new components are supplied with fastening holes that do not have the screw thread
pre-cut. It is the insertion of the first screw into the hole that forms the thread.
CAUTION
Use the following procedure to avoid broken screws and damaged holes:
1. Ensure that the screw is a thread forming screw, refer to Figure 1.
Figure 1 Thread forming screw
If the screw that is used to fasten the component does not appear to be a thread forming
screw, temporarily use a thread forming screw from another location on the machine.
2. Do not assemble the new part into the machine yet, form the screw threads first.
3. Use the correct screw driver or nut driver to ensure a good grip on the head of the screw.
4. Using a moderate axial force, insert the screw to form the thread in the hole, then remove
the screw.
5. Repeat step 4 as necessary until all fastening holes in the new component are threaded
6. Assemble the component on the machine.
Three or four lobes on the end
of the thread
Tapered end to thread
Majority of thread is parallel