Specialized Concentrated Focused
Machine Tool Debugging
「
65
」
Without Electronic Gear
To move workpiece 10mm
Traveling distance per revolution is 6mm,
10÷6=1.6666 revolutions
One revolution needs 2048×4 pulses
1.6666×2048×4=13653 pulses
Input 13653 command pulses.
This conversion should be done in the senior device.
Encoder pulses: 2048
Ball screw pitch:
6mm
Worktable
With Electronic Gear
To move workpiece 10mm,
since command unit is 1
μm,
10mm÷1
μ=1000 pulses
Mechanical conditions and
command unit are specified by
electronic gear in advance.
Encoder pulses: 2048
Ball screw pitch:
6mm
Worktable
Command
unit: 1
μm
Fig. 5-5 Schematic conversion of electronic gear ratio
5.7.3. Computing Method of Electronic Gear Ratio
The setting of electronic gear ratio should be in accordance with the specification of equipment.
Electronic
gear ratio:
B/A
M
Input Command
Pulses
SGDM Servo Unit
SGDM
□
H
Servo Unit
Fig. 5-6 Schematic diagram of electronic gear ratio function
n
m
axle
bearing
of
revolution
per
movement
of
Amount
4
Pulses
Encoder
Pn203
Pn202
A
B
Ratio
Gear
Electronic
n
m
is mechanical deceleration ratio.
5.7.4. Samples of Electronic Gear Ratio Setting
Sample One
As lead screw pitch= 6mm (lead screw travels 6mm per revolution of bearing axle),
―2048‖ (2
13
/2
2
)
pulses will be generated per revolution of servo motor with 13-bit incremental encoder.
Command unit= 0.001mm (lead screw moves 0.001mm per pulse generated by host controller)
Amount of movement per revolution of bearing axle= 6mm/0.001mm=6000
