Magnus VLF Punch

To see the press release, go to http://graphics.kodak.com/global/about_gcg/news/2006/060404a.htm .

Drawings/photos | Dual Punch | Firmware | Parts | Procedures | Sequence of Operation | Specifications | Tools | Troubleshooting

Overview

The Punch Option for the Magnus VLF punches the plates after imaging. The punched holes are customized for each individual customer. The major subsystems of the punch system are the:

• Punch Plate Deflector (photo 3) – deflects the plate up into the punch mechanism.
• Registration Bar (photo 1) – contains vacuum cups that grab the plate and move it to the punch registration pins. It runs on air bearings to reduce friction.
• Punch Extrusion Bar (photo 1) – the main structure of the punch option that the actual punches and punch registration pins mount to. It is hollow to allow the chips from the punches to fall into it and be removed by vacuum.
• Side Registration Pin (photo 5) – this is the pin that registers the subscan side of the plate. It has a flat face that can rotate slightly to conform to the plate edge angle. This pin moves on a leadscrew to move the plate into the correct side position. It uses electronic registration between itself and the punch’s mainscan registration pins to ensure the plate is in contact.
• Leading Edge Rotating Registration Pins (photo 4) – these are the two pins the plate registers to in the mainscan direction. The pins have a flat surface on them so they can be rotated to not contact the plate if not required (any one plate will only use two of the six pins that can be installed). The pins also rotate when the plate is held against them and moving sideways (plate being pushed by the subscan pin). This rotation prevents the plate from scraping on the pins (scraping may damage pin/plate and it will add too much load to the side pin and lower its accuracy). The pins use electronic registration to ensure the plate is in contact.
• Chip Collection (photo 6) – the chips from the punches fall into the hollow punch extrusion bar. An air amplifier sucks the chips through the bar and out into a chip collection bucket mounted on the side of the machine.
• Electronics Tray (photo 2) – this tray holds the electronics boards (a GENINE board, a Daphne board, and two electronic registration boards), the solenoid valves for the pneumatic valves, and the electronic pressure regulators.
• Electronic Pressure Regulators – these regulators control air pressure to the registration bar push cylinders (they move the punch extrusion bar towards the leading edge rotating registration pins) based on an analog electrical input. This pressure is calculated by the firmware based on the size of the plate.
• Service Access Lifting Mechanism (photo 7) – this lifts the punch mechanism vertically so it is out of the way allowing you to service the engine and clamps etc.

Sequence of Operation

This is a high level overview only. For a more detailed sequence of operation, see the firmware sequence list. The sequence of operation shown below is for punching of a single plate.

A plate is picked from the MCU, loaded onto the drum, imaged, and unloaded off the drum as normal. Once the unload table untilts and becomes level, the punch sequence starts.

1. The plate is positioned to be handed off to the punch:
   • The deflector tilts down to contact the unload table.
   • The unload table traveler pushes the plate up the deflector and over the punch registration bar.
2. Control of the plate is now transferred from the unload table traveler to the registration bar:
   • The registration bar turns on its vacuum cups, raises them to grab the plate, and lowers the vacuum cups.
   • The unload table traveler now releases the plate.
3. The plate is moved for registration with the leading edge rotating registration pins:
   • The firmware rotates the two pins required for that particular plate into position and calculates the force needed by the electronic pressure regulators to operate the registration bar push cylinders.
   • These cylinders then move the registration bar until the plate it is holding contacts the leading edge rotating registration pins and is confirmed by the electronic registration.
4. The plate is then moved to the correct subscan position:
   • The side registration pin leadscrew is turned until the pin is in the correct position. That position is determined by a calculation and an NVS offset parameter that allows individual plates to be matched to the positions of their punch locations and the inaccuracies of the side registration pin’s leadscrew. The correct position of the plate on the side registration pin is confirmed by the electronic registration.
   • For the first plate, the leadscrew starts from a Home position that is defined by a fixed course sensor in conjunction with a rotating fine sensor, but after that the firmware keeps track of where the pin is positioned to so that it does not have to go to the Home position first.
5. The plate is then punched:
   • The Daphne board energizes the correct punches. If more than one punch must be energized, the Daphne board staggers the start of each punch motor to avoid too much inrush current and monitors the sensor on each punch to know when they have finished punching.
6. Control of the plate is then handed back to the unload table:
   • The side registration pin moves slightly away from the plate, the registration bar moves back to its starting position, the unload table traveler grabs the plate, the registration bar releases the plate, and the unload table traveler moves the plate into the middle of the unload table ready to be taken away by the ejector to the processor.

In a separate sequence, to clear the punched chips that collect in the hollow punch extrusion bar, an air amplifier turns on and blows the chips into a clear plastic container mounted on the outside of the device. The air amplifier is turned on during initialization. It also runs every 60 minutes under normal operation under the following conditions:

• If the air and punches are available, the air amplifier is turned on (to avoid starving any other devices of air).
• If the air and punches are not available, it will try again in another second.
• If the chip removal has not run within 120 minutes, then the firmware will hold on to resources (air and punches) until it is able to turn the air amplifier on.

Registration bar push cylinders

The registration bar (500-03205A) uses vacuum cups to hold the underside of the plate to the top flat surface of the bar. This bar is then able to bring the leading edge of the plate towards the registration pins to position the plate for punching.
The registration bar has five air bearings made of turcite that float on PEEK tape placed on the sheet metal surface of the punch deflector pan. The air bearings give the bar low friction to help keep from buckling the edges of thinner plates when registering on the punch registration pins. To allow for angular misalignment, a pair of pneumatic cylinder assemblies 500-03536A are mounted to the sheet metal lip of the plate deflector with a pin and a rod end onto the registration bar. Each cylinder has a 10 mm bore x 55 mm stroke with a special slow speed optional seal. The air supplied to these cylinders is controlled by two electronically controlled pressure regulators (342-00075) that are located in the electronics tray of the punch unit. The pressure is controlled to each cylinder by the device firmware based on calculated values depending on the plate size, thickness, orientation, and center offset of the plate versus the pushing cylinders. There are NVS parameters available to set the pushing force correctly. The away side air cylinder has a spring to counteract some of the push force that can pull the plate away from the side edge registration pin when pushing the bar laterally for correct side register position. There are four flow orifices that control the speed of the push cylinders: two located on the pressure regulator bodies themselves and two on the air lines going to the cylinders. The cylinders are somewhat susceptible to friction differences from various sources. The speed at which they push the registration bar is also important. The firmware does an “exercise” routine for the push cylinders every time it initializes the punch. This is because the cylinders have a special slow speed seal which could take a set if sitting in one spot for too long. This exercise routine pushes the registration bar forward and back three times to ensure there is no friction. It also does this before a punch if the firmware detects that it has not punched plate in the last 15 minutes or so.

Registration bar vacuum cups

The punch registration bar uses 36 specially designed vacuum cups made of 40 durometer silicone and 32 mm in diameter. There are four manifolds with nine cups mounted on each (two per each half of the registration bar). The vacuum is supplied by a single high flow low vacuum type vacuum generator (340-00001). The vacuum is fed to the manifolds via ¼ in. lines (two per side—one per manifold). The generator is located in the center of the electronics tray to maintain an equal length of the lines. The vacuum is not modulated in any way. The vacuum cup mounts have 0.007 in. orifices threaded into them to keep leakage to a minimum and allow a variable amount of suction cups to be uncovered while maintaining adequate vacuum.
Each cup is held onto its mount by a barb type fitting on the end of the mount. The mount is threaded into the manifold and has Teflon tape on its threads to ensure sealing. A copper sealing washer sets the height from the manifold face to the mount correctly. Inside the mount there is a 0.007 in. brass orifice with a #10-32 thread that is threaded into the cup mount and glued using Loctite 417 (89-0180). There is also a metal screen with approximately 0.005 in. openings that should keep the orifice from getting clogged.

Punch heads

The Magnus VLF uses individual punch heads that are clamped to a machined extrusion using T-nut type fasteners. The punch heads have motors with cams that push the die to punch through a printing plate. To achieve proper accuracy, the punch heads are adjusted in the mainscan and subscan directions relative to the registration pins.

Magnus VLF vs Magnus 800/Lotem punch heads

The Magnus VLF punch system uses the same punch heads as the Magnus 800 system and also punches the plates emulsion side up. The Magnus VLF can use the Lotem punches, which are emulsion side down, if they are the “single” punch shape type because they work even if mirrored (emulsion up vs. emulsion down). The Magnus VLF punch system can control up to a maximum of 16 motors and 5 registration pin pairs. The Magnus VLF punch system differs from the Lotem and Magnus 800 in several ways:

• The punched chips are collected within a hollow section within the punch base extrusion. This requires a hole being drilled to accept the chips.
• The VLF punches must be adjusted in the mainscan direction due to the long length of the VLF plate and possible punch locations that could affect registration on press if not compensated for.
• The VLF has the ability to “shift” plates on the punch extrusion allowing more latitude to avoid punch shape collisions and punch head interferences.
• The registration pins are not offset in depth, rather, they are “selectable” by switching a pneumatic cylinder on or off certain pairs of pins to send the round part of the registration body forward to touch the plate while the other pin sets are retracted (flat on the round body) and do not touch the plate.

Variable punch heads

There are two types of variable punches (moving punches). The first is the kind that slides in the mainscan direction and the other is the kind that slides in the subscan direction. The reason these exist is when there is interference between punch shapes or bodies that cannot be fixed simply by shifting the group. In these cases, it is necessary to move the punch head. This is done by designing the punch head in 2 pieces with a precision slide and air cylinder to actuate it. The stops are machined directly into the steel bodies and are “hard” stops (the cylinder is not the end stop) to provide an accurate travel. Note that on the variable (traveling) punches there is a need to catch the chips and funnel them to the drilled hole in the extrusion without leaking too much vacuum. This is done by a custom plastic adaptor which you can see in the pictures. You should drill the hole in the extrusion according to where the hole in the adaptor will need it.

Double punch heads

Sometimes you need to incorporate two or even more punch shapes into the same punch body. If you use just one motor to actuate the punch dies, then you can have a double punch that is usually 50 mm wide. This punch, however, does not have a round exit hole for the chips, but has a rectangular hollow section. This requires a rectangular matching hole to be made in the extrusion to keep the punch chips from accumulating and possibly jamming up. Alternatively, a chip guide chute can be inserted into the rectangular cavity of the punch body. The chute has a round exit hole to match the standard 22 mm hole drilled into the extrusion. It simply clips in place and should not be able to come out once the punch is in position.

Dual Plate Punching Option

The dual plate punching option is for customers that require both imaged plates to be punched on the Magnus VLF. The Magnus VLF punching system can only punch plates one at a time, therefore when imaging is complete, the plate farthest from the eject side must be shuffled over to make room for the plate closest to the eject side to be punched first. Because there is more room to store a plate on the right side (away side) of the unload table than on the left side, different hardware is installed on right eject and left eject devices to enable dual plate punching.
Dual plate punching is not supported on Magnus VLF ContinuousLoad devices. On Magnus VLF MCU and Magnus VLF APL devices, the following hardware is installed to enable dual plate punching:
Right eject devices—An extended plate support panel on the home side of the unload table and an additional kicker assembly that pushes the plate back to within reach of the ejector fingers.
  
Left eject devices—An extended plate support panel on the away side of the unload table and the relocation of the ejector sensor bracket and sensor tab.

Kicker assembly

The kicker assembly consists of the kicker fingers, an air cylinder to push the kicker fingers, and two optical interrupt sensors.

• The kicker fingers are part of a pusher bar that is pushed in the direction of the ejector using an air cylinder and a linear bearing arrangement.
• The air cylinder either extends or retracts the kicker fingers.
• The home and away optical interrupt sensors detect where the kickers fingers are.

Plate support panel

The plate support panel is an extension of the unload table and has darts similar to the unload table's darts—the same spacing and height.

Service access

• To remove the home side plate support panel, raise the side furthest from the unload table and lift the panel up from the locating slots on the MAB.
• To remove the kicker assembly, disconnect the quick disconnect connection for the air and sensors and lift the kicker assembly up from the locating slots on the MAB.
• The cable and tubes are routed to the punch electronics tray via a new umbilical cable on the home side of the device. The kicker solenoid valve is located on the punch manifold and the sensors connect to GENINE 4 (J4) in the punch electronics tray.

Specifications

• Leading Edge Punch Specifications

Archived Specifications

• Leading Edge Punch Specification (beta) (Tokan)
• Magnus VLF Punch Option Specifications (beta) (Snel)

Parts

For parts information, see the Punch parts page.

Drawing/photos

• Wiring Diagram (sheets 24 and 25)
• Pneumatic schematic 718-00023G

Procedures

See the Procedures page.

Firmware

• Punch firmware simulator

Firmware groups and settings

• Poffset: Plate offset. This is the offset of the plate and punches relative to the registration pins.
• Goffset: Group offset. This is the offset of the plate, pins, and punches all relative to the center of the punch extrusion.
• Offset: Offset. This is the offset in microns of the side edge registration pin position (and thereby the plate final position for punching).
• Punch group pin set: This is the set of punch registration pins the punch group uses.

Tools

• Punch Image Creation Tool

Troubleshooting

See the Troubleshooting page.