G320, G340 encoder and motor question
Posted by
Kos
on 2002-09-11 00:04:43 UTC
Hi!
I have downloaded the G320 and G340 manuals from Gecko web site.
In the encoder specification it says that for G340 it should be at least 25 line encoder (100 counts per revolution) and for G320 at least 200 line encoder (800 counts per revolution).
does anyone knows why is this different?
I have a bunch of 12 V / 120 W / 20000 RPM brush DC motors that I want to use to run my hobby bench CNC machine. I thought of using 3:1 reduction toothed belt drive from motor to spindle. This would give me nice torque (and thrust about 500N) at the spindle and still having around 6500RPM on spindle which would yield theoretical 9,7 m/min at (300 ipm) rapids.... If I would install 100 line encoder directly on 1.5 mm pitch spindle (not on motor) I would get 0.00375 mm ( resolution which is plenty enough for me).
With 20kHz step/direction source I get 4.5 m/min rapids at 0,00375 step or if I go double step rate (multiplier) I get 9 m/min rapids at 0,0075 resolution.
The questions I have are:
Do you think this will work?
What is maximum encoder frequency that the G320/340 can cope with?
If I use PC (20000kHz step limit) what is better to go with G320 or G340? With G340 seem to loose step resolution with increase of speed and smoothness. Is it worth it?
Thank in advance for your answers!
With best regards,
Matjaz Kos
[Non-text portions of this message have been removed]
I have downloaded the G320 and G340 manuals from Gecko web site.
In the encoder specification it says that for G340 it should be at least 25 line encoder (100 counts per revolution) and for G320 at least 200 line encoder (800 counts per revolution).
does anyone knows why is this different?
I have a bunch of 12 V / 120 W / 20000 RPM brush DC motors that I want to use to run my hobby bench CNC machine. I thought of using 3:1 reduction toothed belt drive from motor to spindle. This would give me nice torque (and thrust about 500N) at the spindle and still having around 6500RPM on spindle which would yield theoretical 9,7 m/min at (300 ipm) rapids.... If I would install 100 line encoder directly on 1.5 mm pitch spindle (not on motor) I would get 0.00375 mm ( resolution which is plenty enough for me).
With 20kHz step/direction source I get 4.5 m/min rapids at 0,00375 step or if I go double step rate (multiplier) I get 9 m/min rapids at 0,0075 resolution.
The questions I have are:
Do you think this will work?
What is maximum encoder frequency that the G320/340 can cope with?
If I use PC (20000kHz step limit) what is better to go with G320 or G340? With G340 seem to loose step resolution with increase of speed and smoothness. Is it worth it?
Thank in advance for your answers!
With best regards,
Matjaz Kos
[Non-text portions of this message have been removed]