Acu-Rite CNC 3500i User Manual

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7 Programming: Canned Cycles, sub-programs
7.
2 Canned Cy
cles
Tool Length Offset is set the same as with any other tool or 
operation. A tool diameter also has to be set in the tool table, as tool 
diameter compensation is built into this cycle (tool diameter 
compensation is not allowed during the use of this cycle).
If X (XCenter) and Y (YCenter) are not programmed, position tool 
center of the thread before the Thread Mill Cycle line:
X and Y rapids to the starting position of the thread.
Z rapids to the safe height specified in P (ZSafePosn).
The Z-axis feeds down to the start cut position H (ZStart). This 
could be above or below the Z position specified in the Z (ZFinish) 
finish position.
Depending on what is in the R (ArcInRad) parameter the tool arcs 
into the first cut position.
Spiral up or down, depending on the difference between "Z" and 
"H" and go counterclockwise or clockwise depending if D 
(MajorDia) is plus or minus.
Then arc-out and feed to the thread center for inside threads or a 
safe distance away from the thread for outside threads depending 
on the value in R (ArcInRad).
Then feed back to the "H" height.
Then feed X and Y to the next depth of cut. The depth of each 
roughing pass is the thread depth specified in the C (ThdDepth) 
parameter minus the stock amount specified in the S (StockAmt) 
parameter, divided by the number of roughing passes specified in 
the E (Passes) parameter.
The cycle repeats this process until the final finish pass. 
It then cuts the thread at the full thread major diameter.
With a cutter diameter of 0.625, this program cuts a 1-8 inside 
thread at X0 Y0. The tool spirals down the thread pitch of 8 threads 
per inch, finishing at a depth of -1. The starting height is 0.1, the safe 
rapid Z (ZFinish) height is 0.5, the major thread diameter is 1”, and 
depth of thread is 0.0625. The arc-in radius is 0.1 and the stock 
amount for the finish pass is 0.002. The rough feedrate is 20.0 and 
the finish feedrate is 5.0. 
G-code format: G181
If you would like all non-cutting positioning moves to be 
rapid, set E (Passes) to a negative number. The idea is to 
initially set "E" as a positive number and after proving out 
the program, change "E" to a negative number for faster 
production. If you only need one pass to size and you want 
the positioning moves to be rapid, set "E" to -1.