The SPINDL Command [MLEP]

The SPINDL command is used to control the rotation of the spindle for mills and lathes, typically using M03, M04 and M05 codes. For EDMs, the SPINDL command controls the wire power supply. For punches, the SPINDL command is used to control the orientation of the punching tool.

Wire EDM Machines

\textbf{SPINDL /} \begin{pmatrix}\begin{array}{l} \textbf{ON} \\ \textbf{OFF} \end{array}\end{pmatrix}

ON activates the power supply for a wire EDM. OFF deactivates the power.

Punch Presses

\textbf{SPINDL / ORIENT}, \mathit{angle}

Specifies the orientation of the punching tool.

Mills and Lathes

\textbf{SPINDL / } \big[\,\mathit{speed}\,\big] \begin{bmatrix} ,\! \begin{array}{l} \textbf{RPM} \\ \textbf{SFM} \\ \textbf{SMM} \end{array}\end{bmatrix} \begin{bmatrix} ,\! \begin{array}{l} \textbf{CLW} \\ \textbf{CCLW} \end{array}\end{bmatrix} \begin{bmatrix} ,\! \begin{array}{l} \textbf{FRONT} \\ \textbf{REAR} \end{array}\end{bmatrix} \begin{bmatrix} , \textbf{MAXRPM}, \begin{pmatrix}\begin{array}{l} \mathit{max} \\ \textbf{OFF} \end{array}\end{pmatrix}\end{bmatrix} \; \ldots

\hspace{.98cm} \ldots \; \big[,\textbf{STEP},\mathit{incr}\,\big] \begin{bmatrix},\textbf{RANGE}, \begin{pmatrix}\,\begin{array}{l} \mathit{gear} \\ \textbf{HIGH} \\ \textbf{MEDIUM} \\ \textbf{LOW} \\ \textbf{AUTO} \end{array}\end{pmatrix}\end{bmatrix}

\textbf{SPINDL /} \begin{pmatrix}\,\begin{array}{l} \textbf{ON} \\ \textbf{OFF} \\ \textbf{LOCK} \\ \textbf{NEUTRL} \\ \textbf{ORIENT} \big[,\mathit{angle}\,\big] \end{array}\,\end{pmatrix}

The first SPINDL command format is used to specify the rotation mode, speed, direction, gear range and upper RPM limit. The second format is used to perform special functions.

\big[\,\mathit{speed}\,\big] \begin{bmatrix} ,\! \begin{array}{l} \textbf{RPM} \\ \textbf{SFM} \\ \textbf{SMM} \end{array}\end{bmatrix}

The spindle mode can be specified in one of two ways; in revolutions per minute, or as a function of the tool contact point velocity. The first type is called RPM. The speed value indicates how many revolutions the spindle should make per minute. The second type is called SFM or SMM (surface units per minute). The speed value specifies the “tool to surface” velocity as a function of feet per minute or meters per minute.

When using a 4-axis lathe in the merge mode, it is more meaningful to have one spindle speed during the whole merge mode. If the spindle RPM value is different for the two heads, the SPINDL command that was most recently processed during the merging process will control the spindle speed. If there is a SPINDL command using SFM or SMM for a head, then the X-coordinate of this head is controlling the spindle RPM. This SFM value may not give a proper cutting speed for the other head. Unless both heads are cutting at the same diametrical distance, it is better to give an RPM value rather than an SFM value.

The spindle mode is modal. Once coded it need not be repeated on every spindle command. On machines that support both modes of operation, each occurrence of a mode keyword will cause the appropriate preparatory or auxiliary code to be generated. To avoid redundant tape codes, only mention the mode when it changes.

\begin{bmatrix} ,\! \begin{array}{l} \textbf{CLW} \\ \textbf{CCLW} \end{array}\end{bmatrix}

The spindle direction can be controlled using the CLW or CCLW keywords. If a machine does not support the specified direction, an error message will be output and processing will continue.

The spindle direction is modal. Once coded it need not be repeated on every spindle command unless the direction changes. Each occurrence of a direction code will cause the appropriate code to be generated if a machine supports both directions. On machines that can change speed without this code, avoid redundant tape information by only mentioning the direction when it changes.

\begin{bmatrix} ,\! \begin{array}{l} \textbf{FRONT} \\ \textbf{REAR} \end{array}\end{bmatrix}

The main or sub-spindle on a mill-turn lathe can be selected using the FRONT (for main spindle) and REAR (for sub-spindle) keywords. If a machine does not support the specified spindle type, an error message will be output and processing will continue.

The spindle type selection is modal. Once coded it need not be repeated on every spindle command unless the selection changes.

The spindle type can also be controlled using the $SPINDLE macro variable (see “Lathe Variables”)

\begin{bmatrix} , \textbf{MAXRPM}, \begin{pmatrix}\begin{array}{l} \mathit{max} \\ \textbf{OFF} \end{array}\end{pmatrix}\end{bmatrix}

When in SFM or SMM mode, the spindle RPM is a function of the cutter distance to the center line for lathes or the tool diameter for mills. As this value becomes smaller, the RPM will increase exponentially. To limit the RPM to a specific value, code MAXRPM,max where max is the upper limit. Coding MAXRPM,OFF or specifying zero for max will cancel the limiting feature.

\begin{bmatrix},\textbf{INCR}, \begin{pmatrix}\begin{array}{l} \mathit{rpm} \\ \textbf{OFF} \end{array}\end{pmatrix}\end{bmatrix}

If a machine does not support SFM or SMM, GENER will output an RPM value that approximates the SFM at the time the SPINDL command is coded. Constant surface speed emulation can optionally be enabled using either the INCR option or the STEP option (see below). When the calculated spindle RPM deviates from the current spindle speed by the specified rpm value or more, a spindle code is output to correct the spindle speed so that the desired SFM/SMM will be maintained. Coding INCR,OFF or specifying zero for rpm will cancel constant surface speed emulation.

\begin{bmatrix},\textbf{STEP} , \begin{pmatrix}\begin{array}{l} \mathit{incr} \\ \textbf{OFF} \end{array}\end{pmatrix}\end{bmatrix}

This is an alternative to the INCR option (see above) to optionally enable constant surface speed emulation. The value of incr indicates the number of RPM increments for the current gear range. This is equivalent to using the INCR option with an RPM value calculated as the total range of the current gear divided by incr. Coding STEP,OFF or specifying zero for incr will cancel constant surface speed emulation.

As an example, if the current gear range is from 100 to 500 RPM and “STEP,8” is programmed, the spindle speed will be adjusted when the calculated spindle RPM deviates from the current spindle speed by 50 RPM ((500–100) / 8 = 50) or more.

\begin{bmatrix},\textbf{RANGE}, \begin{pmatrix}\,\begin{array}{l} \mathit{gear} \\ \textbf{HIGH} \\ \textbf{MEDIUM} \\ \textbf{LOW} \\ \textbf{AUTO} \end{array}\end{pmatrix}\end{bmatrix}

The spindle gear range can be controlled using the HIGH, MEDIUM, LOW and AUTO keywords. HIGH and LOW gears are equated to the fastest and slowest spindle speed ranges respectively. MEDIUM will select the mid-range gear if there is one. Do not request a MEDIUM gear if the machine has an even number of gear ranges.

The user can also specify AUTO. If an auto M code is defined in QUEST, this code will be output and all M codes to change gears will be suppressed. If an auto M code is not supported, then GENER will automatically output the gear change codes based on the specified spindle speed. If AUTO is not available and a gear cannot be specified using HIGH, MEDIUM or LOW, then the RANGE,gear format must be used, where gear is the gear number. Gear number 1 is the LOW gear. Higher gear numbers represent higher machine gears. If the RPM coded along with a gear range is not within the specified limits, the gear range will be corrected and a message will be output.

\textbf{SPINDL /} \begin{pmatrix}\begin{array}{l} \textbf{ON} \\ \textbf{OFF} \end{array}\end{pmatrix}

The spindle is stopped by using the OFF option. If the machine is in a units per revolution feed rate mode, stopping the spindle may cause unpredictable results on the machine and will cause errors to be generated in the listing.

To reinstate the last spindle condition, the ON keyword can be coded instead of the full command specification. If ON is used on the very first spindle command, the system defaults will be used. They are: minimum RPM for the default gear range set in QUEST; clockwise rotation; default gear range set in QUEST; and highest available speed for MAXRPM.

\textbf{SPINDL /} \begin{pmatrix}\begin{array}{l} \textbf{LOCK} \\ \textbf{NEUTRL} \\ \textbf{ORIENT} \big[,\mathit{angle}\,\big] \end{array}\,\end{pmatrix}

There are three special functions in addition to the standard spindle control; they are LOCK, NEUTRL and ORIENT. The spindle is considered OFF when any of these are specified. A spindle ON command should be coded to restart the spindle.

The LOCK function is used to stop the spindle and lock it so it cannot be rotated.

The NEUTRL function stops the spindle and disengages the spindle motor to allow the tool to be freely turned.

The ORIENT function is used to stop and lock the spindle at a known angular position, generally using an M19 code. The angle of orientation is measured in degrees off the positive X-axis in a counter-clockwise rotation direction. This angle indicates in which direction a known point on the spindle will point. If the angle is omitted, the previous orientation angle will be used. If the angle is omitted on the first use of the ORIENT function, a warning message will be output and the minimum angle will be used.