Acu-Rite CNC 3500i user manual 164

7.2 Canned Cycles

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.

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.

G-code format: G181

164 7 Programming: Canned Cycles, sub-programs