I’ve recently adapted my LitePlacer pick and place machine to also do some automated liquid dispensing. The LitePlacer is controlled with a 4-axis TinyG and I’m driving it with UGS. I’m having an issue and I’m hoping someone here can help me out.
Problem- I want to draw a lot of short lines with a dispensing needle “tip”. This involves some accel/decel time in which I do not want the dispensing enabled. To the best of my knowledge, conventional G code only allows me to-
1) M08 (enable dispensing (open the air solenoid using the coolant i/o)
2) G1 …. (motion starts, runs, then stops)
3) M09 (disable coolant)
The problem is that it starts and stop dispensing when the machine is stationary leaving a wider “blob” at the beginning and end of the line.
What I really want is-
1) G1 … (motion starts)
2) (after reaching full speed or some static delay) M08 (start dispense)
3) … (line is being drawn)
4) (before starting decel) M09 (end dispense)
5) (G1 starts decel and slows to at stop)
Is there any way to send commands to a separate buffer and achieve the desired behavior?
Thanks!