Roller Assembly

See also Commands | Parts | Procedures | Troubleshooting

Description | NVS Parameters | Theory of Operation

Description

Attached to the side clamp plate assemblies, between the LEC and the TEC backbones. Keeps the plate tight against the drum during plate loading and plate unloading.

The main components are:

• Rollers
  Each roller is made of polyurethane rubber. Mounted on the backbone using ball bearings at each end. The center roller is symmetric; the outer rollers are not. The outer rollers must be assembled to the backbone such that the grooves in the roller match the grooves in the drum. Otherwise, plates will be damaged as they are rolled on the drum. Two shims behind the center roller bearing blocks compensate for the roller backbone deflection curve.
  Rollers made of a new blue EPDM rubber have been released for use with the new generation of positive thermal plates. These rollers are also installed to correct plate marking problems on Kodak thermal plates. An upgrade kit (02-4270A) is available from Logistics. The kit is installed at Creo's cost at sites with roller mark problems on Kodak plates. Sites wanting to use positive thermal plates are required to pay for the kit and installation costs though the plate vendor will most likely pay for the upgrade.
• Clamp plate assemblies
  Mounted at either end of the engine frame, support the backbones. Cam followers on the backbone ends roll on nickel-plated angles attached to the side plates.
  The setup is the same as for all backbones. Note that the backbones do not slide in grooves as with the 3244 engine.
• Backbone pneumatic cylinders
  Roller backbone: 55-0281 (2.5" x 1¼") Round body used on VBI to V48 & B1 to B120
  Roller backbone: 55-0649 (1.5" x 1.5") Square body used on V49+, B121+
  TEC backbone: 55-0282 (3" x 2¼")
  LEC backbone: 55-0281 (2.5" x 1¼") VLF Platesetter only

  Actuate the TEC, LEC, and roller backbones.
  One cylinder on each clamp plate assembly. Attached to the backbone by rod ends. For VLF Trendsetters that are upgraded for the film option, the roller cylinder must be replaced with 55-0649 for machines B121.

• Backbone reed switches
  Detect the extend and retract position of the backbone. The setup is the same as for all backbones.
  For each backbone, 1 magnet at each end of the backbone, and 2 sensors on the clamp plate assembly.
  Each magnet is attached to the backbone by a bracket. The brackets are slotted axial to the drum, and the magnets are slotted perpendicular to the plane of the backbone. The sensors are attached to the clamp plate assemblies. They are slotted roughly in the direction of the cylinder actuation.

Roller Bearing Differences between 5080 and 5880 engines (VLF Platesetter only)

The VLF Automatic engines use modifed roller bearing blocks for the roller backbone assembly. The mounting holes for the pieces are slotted 4 mm each side of center such that the roller axis are actually 4 mm above the backbone centerline or 4 mm closer to the trailing edge backbone. This is done to improve the unload geometry with 5880 engines by bringing the plate closer to the unload skin and cow catcher and away from the under side of the load skin.

NVS parameters

AL module (set al xxx)

al drs (drum_roller_sensor)
al rlrpos (roller_drum_pos ) (VLF Trendsetter)

ALTIM module (set altim xxx)

altim drt (drum_roller_timeout)

Theory of operation

VLF Platesetter Plate Loading Sequence (VLF Platesetter only)
VLF Platesetter Plate Unloading Sequence (VLF Platesetter only)