12 Functional Descriptions 10.94
12.9.2 Description of function
The thread lead is programmed under address K (I, J). The sign in front of K shows the
direction of rotation (see example above).
Clockwise/counterclockwise rotation is defined in the Programming Guide in the section
Coordinate systems.
A lead must be assigned to the individual axes with G36 as well as with G33, G34, G35. The
assignment is stored in MD 304*.
The address for the thread lead must correspond to the axis with the larger path (in the
example path X = 10 mm, path Z = 32 mm thread lead K belongs to axis Z), otherwise
alarm 3006 ”Wrong block structure” is triggered. Alarm 3006 is also triggered if thread lead
zero is programmed.
Three axes must be programmed, of which exactly one must be a rotary axis. If more than
three axes are programmed, alarm 3006 ”Wrong block structure” is triggered.
G98 is triggered internally with G36, i.e. the programmed feedrate F refers only to the rotary
axis in rev/min.
The resulting path feedrate (C axis and linear axis) is derived internally from the programmed
lead.
The rotary axis (in this case C axis) must be written in every block with G36 active (N30).
Starting conditions at block transfers can be influenced with G60 or G64.
12.9.3 Parameter set switchover with thread functions
As the function ”Rigid tapping” can be greatly influenced by mechanical and design aspects
of the machine, a second set of parameters (servo gain factor, feedforward control factor, time
constant for dynamic feed forward control) can be stored in MD 1320*,
MD 1260* and MD 1324* for adapting the function to the machine. Function G36 is used to
switch over to the second parameter set if the second servo gain factor (MD 1320*) has a
value other than 0.
Only the parameter sets for the axes involved in the thread cutting operation can be switched.
The values of the second parameter set are loaded by the position controller while the control
is booting. It is thus possible to maintain G64 operation when G36 is programmed.
Note:
For further information, please refer to the description of the "Parameter set switchover"
function.
12.9.4 Option
The function G36 can only be operated when the option bit ”Rigid tapping” is set, otherwise
alarm 2047 ”Option not available” is triggered.
12.9.5 Reset behaviour
If M02/M30 is programmed, or on operator panel reset, the initial setting for the first G group
stored in MD 108* is active.
The setting of machine data 521*, bit 4 dictates whether C axis mode remains active.
MD 521*, bit 4 = 0 C axis mode remains active.
MD 521*, Bit 4 = 1 C axis mode is switched off with RESET.
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SINUMERIK 840C (IA)