electronic.alchemy :: optical cycle sensor installation
where the past meets the future
letterpress > monotype > optical cycle sensor installation

optical cycle sensor installation

Created by hww3. Last updated by hww3, 29 days ago. Version #6.

Items included with the sensor package:

Items you must provide:

The following items are needed if you are retrofitting an older interface with the optical cycle sensor:

Installation Procedure

Note: if you are not retrofitting an optical cycle sensor on an older interface installation, you may skip to step #2.

  1. Install the 2 position cable connector on the main interface board

a) This connector has a plastic orientation tab for the cable. This tab should be positioned toward the rear of the interface board (the parallel edge furthest from the LED status indicators

b) The connector should be located within a white circle identified as C1, near the power indicator LED.

c) The pins of the connector will be a tight fit. You may wish to use a small block of wood to press both pins into the interface board at the same time. Note that the amount of force required to insert the connector may cause the pins to come loose from their plastic base. If this happens, simply press the pins in individually until they are both positioned evenly.

d) You may wish to insert a connector from the cable into the board connector in order to establish that you've pressed the pins far enough into the base.

e) Once satisfied with the positioning of the pins, solder both pins using a soldering iron and flux core solder suitable for electronics work.

  1. Attach the optical wheel assembly (see photo.)

a) The optical wheel assembly is attached to the lower right hand cam shaft at the front of the composition caster using a #6-32 machine screw. This cam shaft should have a centering hole, and this hole will need to be enlarged and then tapped.

b) Begin by drilling the mounting hole in the cam shaft using the provided #36 drill bit.

c) It is advisable to mark the depth of the hole using a piece of adhesive tape wrapped around the drill bit at the appropriate depth. The exact depth will vary depending upon the mounting hardware and your machine, but a good starting point is 1 inch.

d) Make sure that the hole is drilled square to the face of the cam shaft, in order to minimize wobble. The best way to ensure squareness is by using a level attached to your drill.

e) Alternately, you can use a pair of large quads placed in an "L" configuration against the end of the cam shaft. By placing the drill bit within and against the inside corner of the quads, you can square the drill bit against the cam shaft.

f) You may wish to use a drop or two of oil to lubricate and cool the drill bit, however this is not strictly necessary.

g) Once the hole has been drilled, use the included #6-32 tap to tap the hole.

h) Once the hole has been tapped, you may mount the optical wheel assembly. Remove the nut from the end of the assembly, which is used to hold the components together during transport.

i) The order of the components (starting from the head of the screw) should be:

·         Steel washer

·         Unprinted Mylar disc (as a protective layer)

·         Mylar discs with opaque sectors (3)

·         Unprinted Mylar disc (as a protective layer)

·         Steel washer

·         Nylon standoff

j) Tighten the screw enough that the discs do not spin. When adjusting the cycle sensor, this screw may be temporarily loosened in order for the various discs to be rotated relative to each other and the cam shaft.

  1. Install the sensor and bracket

a) For English machines: The sensor and bracket should be installed by mounting the bracket through a machine screw already present on the cam gear cover (see photo above).
b) For American machines: A hole will need to be drilled and tapped in the cam gear cover. Use the provided drill and tap, using care not to damage the cam shaft gears when performing the machining operations. 

c) This screw should be tightened enough that the bracket does not move, and may be loosened temporarily for adjustment.

  1. Attach interface cable

a) The sensor board contains 2 connectors: power and cycle sense. The main interface board has a corresponding pair (cycle, which is currently used for the magnetic cycle sensor) and power, which you installed in the first step.

b) The interface cable has a pair of 2-position connectors at each end. These connectors are identical, however the connections on each end must match. You can verify this by noting the colors of the wires (such as black/white and red/green) attached to each end and making sure that the connections to the boards on each end match (cycle sense to cycle sense and power to power).

c) The connections are keyed, so beyond making sure the connections correspond, it is not possible to make incorrect connections.

d) Connect the power connection on the interface board with the power connection on the sensor board. Make a note of the wire colors and ensure that the correct pair is used on each end.

e) Connect the cycle sense connection on the interface board with the cycle sense connection on the sensor board.

f) Optionally, use wire ties to secure the interface cable out of the way.

  1. Test the sensor

a) Connect the interface board to the power supply. The power indicator LED on the interface board should light (among others).

b) Verify that the power indicator LED on the sensor board is lit.

c) Verify that the cycle sense indicator LED on the sensor board is lit.

d) Verify that the cycle indicator LED on the interface board is lit.

e) Trigger the sensor by using a piece of paper. Insert the piece of paper between the posts of the optical sensor (the black U-shaped device on the underside of the board.) When you do this, the cycle indicator LED should be extinguished and illuminated when you remove the piece of paper.

f) Verify that the cycle sense LED on the interface board also responds in coordination.

  1. Adjust the cycle sensor

a) Rotate the cycle sensor down over the optical wheel so that the edge of the wheel passes between the posts of the cycle sensor.

b) Position the hand-wheel of the caster just before the air tower clamp activating rod begins to move downward. Note the direction that the optical wheel rotates in order to determine which edge of the blacked out sector will pass through the sensor posts first (that is, the sector's leading edge.)

c) Rotate the front-most of the marked Mylar discs in the cycle sensor wheel so that the leading edge of the blacked out sector on the just causes the cycle sense LED to be extinguished. You've just aligned the cycle "on" with the beginning of the air request from the casting machine.

d) Rotate the hand-wheel of the caster so that it is positioned just as the air tower clamp activating rod is arriving at its full upward position.

e) Rotate the rear-most marked Mylar disc (without rotating the front-most marked disc) so that its trailing edge just causes the cycle sensor to illuminate. You've just aligned the cycle "off" with the end of the air request from the casting machine.

f) Finally, rotate the middle Mylar discs (without touching the front or rear marked disks) so that they form a complete, unbroken, sector between the leading and trailing edge. This will cause the sensor to remain off during the duration of the air request.

g) Depending on your machine, it may be necessary to enlarge individual sections so that a wide enough sector is produced. You may use a permanent marker (such as a Sharpie). Ensure proper opacity of the sector by "painting" on both sides of the Mylar disc.

  1. Test

a) With the interface connected and powered on, cycle the caster by hand to ensure that the cycle sense LEDs are illuminated when the air bar clamp is "released", or up; and extinguished when the air bar clamp is "activated", or down.

  1. Adjustment

a) The air cycle is completely customizable to the needs of a particular machine or job.

b) To enable the air cycle to begin earlier, simply rotate the disc pack forward in its direction of travel.

c) To extend the length of the air cycle, make the blacked out sector wider by rotating the trailing edge backward against the direction of travel. When doing this, make sure that the leading edge is not altered, otherwise you will affect how soon the air is turned on.


This page (letterpress/monotype/optical cycle sensor installation) contains 1 Attachments
Name Type Size Updated Updated By
cycle_sensor_installed.jpg image/jpeg 190 kb Friday, 6 September 2013 Bill Welliver

Not categorized | RSS Feed | BackLinks

comments powered by Disqus