Soft Start for Spindle on Syil SX3 Mill using G Code

[Chrisjh]

Hi,

I have a Syil SX3 Mill fitted with the original Seig Spindle Control Boards.

Later boards have a "soft start" feature for the spindle speed. I personally don't like the later boards because of the slow accelation rate to spindle speed. The soft start feature appears to emulate pushing of the front panel up arrow buttons and is set in firmware. It is far too slow for the spindle to come up to full speed of say, 3000rpm.

The original boards do not have a soft start feature and this places a lot of stress on the spindle motor and belt when a speed of 3000+rpm is selected under G Code Control.

I have a G Code solution which meets my requirements which I tested this arvo as follows:

(Soft Spindle Start Template)
(This routine brings the spindle up to 3000 rpm in small steps)

(CJH 27Jun08)

G00 G17 G21 G40 G49 G50 G64 G80 G90 G94
M6 T6 (5mm Drill)
M3 S750
G04 P100
S1000
G04 P100
S1500
G04 P100
S2000
G04 P100
S2500
G04 P100
S2800
G04 P100
S3000
M8 (Coolant on)
F2000
G00 Z10
G00 X0 Y0 Z3

G00 Z15 F2000

M5 M9 (Spindle and Coolant Off)

G00 X0 Y0 (Return to start position)
M30
%

The "G04 Dwell in ms" config settings under "General Config" in Mach 3 or Quantum must be selected for this code to work. I am using Quantum at the moment.

What the code does is to start the spindle at 750rpm, then waits (dwells)for 100ms (0.1 seconds), then increases to 1000rpm, then waits for another 100ms, and repeats this in 500rpm increments until 3000rpm is acheived. The speed ramp up to 3000rpm happens very quickly and smoothly without the stress on the motor and belt.

You can experiment with G04 Pxxx dwell times and the speed start speed and increase increments to suit your machine.

Hope is is useful to others.

Regards

Chrisjh