Programming manual.
CNC 8070
ELECTRONIC THREADING AND RIGID TAPPING.
10.
Electronic threading with constant pitch (G33)
·181·
(REF: 1709)
Feedrate behavior.
The threading feedrate depends on the programmed spindle speed and thread pitch
(Feedrate = Spindle speed x Pitch). The electronic threading is carried out at 100% of the
calculated feedrate and these values cannot be modified from the CNC's operator panel or
via PLC.
Behavior of the spindle speed and of the spindle speed override
If the OEM allows it, (parameter THREADOVR), the user can modify the speed override from
the operator panel and, in that case, the CNC will adapt the feedrate automatically respecting
the thread pitch. In order to be able to modify the override, the feed forward active on the
axes involved in threading must be higher than 90%.
If more than one G33 have been programmed for the same thread, all the threading
operations must start at the same speed; otherwise, the entry point (start) to the thread will
not be the same in all the threads. The CNC permits changing the spindle override during
the thread cutting pass.
If more than one G33 have been programmed for a multi-start (multi-entry) thread, all the
threading operations must start at the same speed; otherwise, the angle between the starts
(entry points) to the thread will not be the same as the one programmed. The CNC permits
changing the spindle override during the thread cutting pass.
Considerations about thread blending.
When working in round corner (G05), the CNC lets blend different threads seamlessly in a
single part. When thread blending, the CNC only takes into consideration the angular position
of the spindle (Q1) in the first thread, after activating G33 or G34. The CNC ignores parameter
Q1until this function is canceled and activated back and it is synchronized when going
through that angle.
Blending a thread of fixed pitch (G33) with a thread of variable pitch (G34).
The starting pitch of the variable thread (G34) must be the same as the pitch of the fixed-
pitch thread (G33). The pitch increment of the variable thread will be half the increment
("K1"/2) in the first turn and a full increment "K1" in the following turns.
Blending a thread of variable pitch (G34) with a thread of fixed pitch (G33).
This combination is used to end a variable-pitch thread (G34) with a portion of the thread
that maintains the final pitch of the previous thread. In this case, the pitch is not programmed
in the fixed-pitch thread G33 and the CNC will use the last pitch of the previous thread.
Properties of the function and Influence of the reset, turning the
CNC off and of the M30 function.
Function G33 is modal and incompatible with G00, G01, G02, G03, G34, G63 and G100.
On power-up, after an M02 or M30 and after an emergency or a reset, the CNC assumes
function G00 or G01 as set by the machine manufacturer (parameter IMOVE).
G33 Z-40 K2.5
G34 Z-80 K2.5 K1=1
G34 Z-50 K2 K1=3
G33 Z-100
To Next Page
Loading...
