440 and 770 Mills not completing G Code steps sequentially

Mill
1

We are finishing up building a work cell that includes (2) PCNC440 and (1) 770M mills. The G-code is very simple and straight forward. While performing test runs of each machine we’ve noticed that some steps if the G-code will happen together rather than sequentially.

The place that is most noticeable is when a spindle start command is before a move command.

Here’s an example:

S1000 M3

G00 X0. Y0.

If the Single Block command is used with the above example the spindle will not start until the rapid move block is selected, then both actions happen at the same time.

Any help would be greatly appreciated

2

Can you post more of the code?

3

I’ve noticed the same behavior in certain specific cases.

Running in single block mode:
G37
M8

will set the tool length and immediately after retracting the spindle will start the coolant. It’s mildly annoying but doesn’t seem to affect any of the actual movement blocks so I’ve just gotten used to it and moved on.

4

Here is the code for this test program:

(CNC 1 Drill Test)
G90 G54 G64 G50 G17 G40 G80 G49 (these are standard operating instructions)
G20 (inch)

T1 M6 (Call for tool 1);

G00 G43 H1 Z.5 (move the Z axis to clearance plane above the zero point compensating for the length of tool 1);
G00 x-2. Y2. (Move table to the robot access location);
m00

S1000 M3 (Turn on spindle, Clockwise rotation);

G00 X0. Y0. (Rapid move table to machining position);
G00 Z-.25 (Rapid Z axis down to depth);
G00 Z.5 (Rapid Z axis up to clearance plane);
M05;

M99 (Return to the beginning of the program);

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