untitled SCREEN ALIGNMENT MODULE OVERVIEW CHAPTER 18 SCREEN ALIGNMENT MODULE OVERVIEW Item Description Item Description 1 Chase Clamp (2 positions) 6 Chase Clamp Regulator 2 Roller Counter Plate (4 po.
Trang 1Chapter Issue 1 Jan 07 Technical Reference Manual 18.1
OVERVIEW CHAPTER 18 SCREEN ALIGNMENT MODULE
OVERVIEW
2 Roller Counter Plate (4 positions) 7 Y Actuator
5 Left Hand Printhead Assembly
Plan View of Screen Alignment System
Machine Front
9
1
2
3
4
2 2
1 2
View on Arrow A
A
Trang 2The screen alignment system is one of the most sensitive and critical components of machine accuracy The alignment system consists of three stepper motor driven linear actuators in contact with the chase (adjustable screen mount) which is a free floating mechanism sprung against the three actuators The actuators are configured in a three point contact arrangement and are controlled and driven independently to give maximum flexibility in screen movement
The screen is aligned to the board each machine cycle unless non-vision is selected An algorithm determined by image capture is calculated in software, this sets the direction and distance that each actuator must move to align the screen to the board Once correctly aligned the chase is clamped by two pneumatic chase clamps, to the left and right printhead assemblies, so that the alignment is maintained throughout the rest of the print cycle
A spring fitted between the actuator and the chase provides an anti-backlash mechanism to ensure accurate positioning is always achieved
All positioning of the screen actuators is referenced from the home position and calculated in the machine software The screen actuators only home during initialisation, which can be from power-up or exiting diagnostics When homed the stepper motor retracts the actuator plunger until the motor stalls The stepper motor reverses direction and drives the actuator plunger out 20mm For information on the chase clamp solenoid and the chase clamp regulator refer to the Pneumatics Chapter
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ELECTRICAL SCHEMATIC ELECTRICAL SCHEMATIC
S X1
Actuator 9M07
3 5 7
M36PL25 1 3 5 7
S X3
SK3 a2 a4 a6 a8
SK3 c28
Actuator 9M06
3 5 7
M36PL24 1 3 5 7
SK1 c2 c4 c6 c8
SK1 c30
Actuator 9M05
3 5 7
M36PL23 1 3 5 7
SK1 a2 a4 a6 a8
SK1 c28
1 2 4
CAN_H CAN_L
CAN Out
Chase Clamp
7 2 3
1 14
NOTE The
Trang 4TEST CYCLES
TEST CYCLES
Carry out the following procedure to access the Test Cycles:
1 Select Maintenance.
2 Select Test Cycles.
3 The following options are displayed:
Dry Align Test Selecting this function initiates the machine to run Dry Alignment accuracy
tests
With data logging set to On, all test data is output to a Test.log file With data logging set to Off, all test data is output to a Test.dat file.
Accuracy Test Selecting this function commences a series of 4 tests:
With data logging set to On, all test data is output to an atest.dat file that can be
imported into a Lotus spreadsheet to assist in determining the cause of location accuracy problems associated with camera positioning, chase clamping and
table movement Pressing the Stop Run key at any time during the sequence
of tests terminates the cycle on completion of the respective test and return to the previous menu
To recommence the test cycle select Accuracy Test, this starts the tests at Test
1 again and not where the test cycle was previously terminated
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TEST CYCLES
Data Logging On/
Off
Selecting this function enables/disables data logging from within the main menu without the necessity of entering the diagnostics mode
With data logging enabled, the following data files are created on the PC hard drive giving information on certain machine functions:
records fiducial locations for each camera cycle
detection data for the 50 locations
stroke
pressure hardware enabled The file records the amount of steps the squeegee
is driven down with the pressure achieved
records positional deviations of the screen fiducial
Trang 6TEST CYCLES