Product

• Lotem^® 800 Quantum
• Lotem 850 Quantum
• Lotem 400 Quantum
• Lotem Quantum Spectrum

Component

Carriage-beam holding pin

Symptoms

The start line of some of the jobs shifts around the drum approximately 100 microns towards the gripper. This happens mainly at the end of the plate (near 80-95%). The shift is anywhere between a few millimeters and 0.5 millimeters wide, and the exposure lines shift down by a few millimeters. When this happens, one swath shifts, followed by one that does not. A hairline-thin black line appears on the border of every shift, indicating a carriage jump of approximately 10 microns, as shown in the example below.

Cause

The carriage-beam holding pin slides backwards, leaving the end of the carriage to hang trembling in mid-air.

Solution

Pull the pin back to its proper location, as described in the following procedure:

1. Put your hand at the end of the carriage beam, and check whether the carriage slides down.
2. Check whether the carriage-beam holding pin moves backwards toward the carriage beam.

3. Run "head install on" to send the carriage along the beam, and check for inconsistent error values.
4. Make sure there are no cables being "stretched" towards the end of the carriage travel.
5. Extract and replace the short V-block pin with a larger pin.

6. Run "head install on" to send the carriage along the beam and check that the error value is consistent along the entire beam. If the error is inconsistent, adjust the carriage parallelism towards the drum.

Technical contact(s)

Nir Peleg

Submitted by

Nir Peleg

Date submitted

25 Dec 2003