Engine

See also NVS Parameters | Parts | Procedures | Troubleshooting

This page contains theory of operation for the overall VLF engine. For details of specific parts of the engine, see Balance weights | Carriage | Drum | Edge detection strip | Encoder | Engine mounts | LEC assembly | Plate flyoff sensor | Registration blocks | Roller assembly | TEC assembly | Temperature sensors

• VLF Trendsetter Engine line drawing
• VLF Platesetter Engine line drawing

Commands | Description | Theory of Operation

Description

The main functions of the engine include:

• loading the plate onto the drum
• synchronizing the moving parts of the engine during imaging
• unloading the plate from the drum

See:

• Engine size (MLF and VLF)
• VLF Trendsetter and VLF Platesetter engines compared
• Mechanical alignment
• Plate thickness

Engine size (MLF and VLF)

The VLF engine comes in two mechanically distinct sizes:

• 5080 (MLF)
• 5880 (VLF)

The first two numbers indicate the maximum plate length, in inches (wrap plate cutoff dimension around the drum). The last two numbers represent the maximum plate width in inches (dimension along the drum).

Each machine is shipped with a dongle which contains hard-coded information on the model. This prevents the users from upgrading the model by simply changing some NVS parameters.

The main differences between the 5080 and 5880 engines are:

• drum diameter
• drum pin pillow block placement
• clamp plate assemblies and placement
• drum motor mounts
• drum belt covers
• leading edge backbone rod ends
• roller bearings

VLF Trendsetter and VLF Platesetter engines compared

The engines for the VLF Trendsetter and the VLF Platesetter are very similar. They share the same:

• Base casting
• Drum
• Plate clamps
• Drum motor and electrical/mechanical drive system
• Carriage motor and mechanical drive system
• TEC mechanism
• Drum roller mechanism
• Balance weight system

The main differences are:

• LEC actuation
• Air solenoids
• Sensor and actuator wiring
• Carriage drive electronics
• Engine satellite board

Mechanical alignment

The drum, encoder disk, drum pins, pillow blocks, tracks, registration blocks, ballscrew drive pulleys and frame are carefully aligned and measured for mechanical accuracy. These measurements are part of the geometric correction values used to ensure image accuracy and repeatability. Any adjustments made to the mechanical alignment of the drum or encoder disk or track mounting requires a full geometric accuracy test and recalibration. Change the mechanical setup only after consulting Creo engineering personnel.

Plate thickness

The engines are set up for one of two ranges of plate thickness when they leave the production floor:

• 0.006" to 0.016"
• 0.010" to 0.020"

The engines can be reconfigured in the field for either range.

For green and HRX heads, the depth of focus is large enough do to the full range with the factory settings.

For thermal heads, follow the procedure for setting the focus offset using a 0.012" plate or a 0.016" plate to set up properly for the
0.006"–0.0016" and 0.010"–0-0.020" ranges respectively.

Commands

carriage
drum
engine (Trendsetter only)
lec
rlr
tec
time engine

NVS parameters

AL module

al b1so (bal1_sensor_offset)
al b2so (bal2_sensor_offset)
al bdo (balance_detent_offset)
al bes (bal_cyl_ext_sensor) (VLF Platesetter only)
al brs (bal_cyl_ret_sensor) (VLF Platesetter only)
al bsv (balance_search_vel)
al bto (balance_tec_offset)
al bwi (balance_is_installed) (VLF Platesetter only)
al cbw (check_balance_weights)
al drs (drum_roller_sensor)
al eii (engine_is_installed)
al els (engine_lock_sensor) (VLF Platesetter only)
al lecpos (lec_drum_pos)
al lecs (le_clamp_sensor)
al pls (plate_length_sensor) (VLF Platesetter only)
al rlrpos(roller_drum_pos ) (VLF Trendsetter only)
al tecoff (tec_offset)
al tecpark (tec_park_pos)
al tecpo (tec_plate_overlap)
al tecs (te_clamp_sensor)
al tems (te_magnet_sensor)
al teuls (te_unlock_sensor)

ALTIM module

altim bct (balance_cyl_timeout)
altim bft (balance_find_timeout) (VLF Trendsetter only)
altim bwst (balance_find_timeout) (VLF Platesetter only)
altim bwt (balance_cyl_timeout) (VLF Platesetter only)
altim drt (drum_roller_timeout)
altim esd (driver_switch_delay) (VLF Platesetter only)
altim lec (le_clamp_timeout)
altim load (load_timeout)
altim move (move_timeout) (VLF Platesetter only)
altim rmd (sensor_delay) (VLF Platesetter only)
altim tcm (tc_move_timeout) (VLF Platesetter only)
altim tec (te_clamp_timeout)
altim tesd (te_sensor_delay)
altim teut (te_unlock_timeout)

CARRIAGE

accel (max_accel)
again (driver_accel_gain)
coff (cos_offset)
cph (centre_plate_to_home)
eatt (edge_attempts)
esearch (edge_narrow_search)
espeed (edge_speed)
espot (edge_spot_width)
fedge (fast_edge_search)
gearing (srot_per_lrot)
hgain (driver_hold_gain)
ispeed (init_speed)
kspeed (knee_speed)
mgain (driver_move_gain)
mspeed (max_speed)
mtravel (max_travel)
period (accel_period)
pgain (driver_plot_gain)
pitch (mil_per_lrot)
psteps (plot_accel_steps)
raccel (retrace_accel) (VLF Platesetter only)
rknee (retrace_knee_speed ) (VLF Platesetter only)
rspeed (retrace_speed ) (VLF Platesetter only)
scyc (steps_per_scyc)
soff (sine_offset)
steps (steps_per_srot)
turbo (turbo_retrace ) (VLF Platesetter only)
wsearch (edge_wide_search)

DRUM module

Default values summary:

• VLF Platesetter
• VLF Trendsetter

chkfly (check_flyoff)
dgh (deriv_gain_hall)
dgp (deriv_gain_posn)
dgr (deriv_gain_posn)
dgs (deriv_gain_run)
dgv (deriv_gain_vel)
diam (nominal_diameter)
epos (edge_position)
gear (drum_gear_ratio)
hppr (hall_pulses_per_rot)
igh (integ_gain_hall)
igp (integ_gain_posn)
igr (integ_gain_run )
igs (integ_gain_soft)
igv (integ_gain_vel)
iner (drum_inertia)
maxdiff (max_hall_vs_enc_diff )
mtcn (motor_torque_const)
mtol (move_tolerance)
pacc (position_accel)
pgh (prop_gain_hall)
pgp (prop_gain_posn)
pgr (prop_gain_run)
pgs (prop_gain_soft)
pgv (prop_gain_vel)
vacc (velocity_accel)

Theory of Operation

VLF Platesetter Plate Loading Sequence
VLF Platesetter Plate Unloading Sequence