Can Puma 2000SY B-Axis Drill Both Spindles at Once?

The operator sees one turret station carrying two opposed drills: a .187 in drill faces east and a .339 in drill faces west. The requested cycle feeds the turret in Z-minus into the main-spindle work while the subspindle moves in Z-plus onto the opposite drill. Before commanding both motions together, determine whether the Fanuc control can coordinate the turret Z axis and the Puma 2000SY B axis in one cutting path, and whether each motion can use the feed reference required by its spindle.

What should the operator screen show first?

Open the axis-position, spindle, and modal-status pages. The screen must distinguish commanded position from actual position for the turret Z axis and the B axis. It must also show which spindle is running and how the active feed mode interprets the programmed feed.

If commanding B produces subspindle axial travel, continue to the coordination check. If it produces rotary motion, another movement, or no programmable motion, stop: the program concept is using the wrong axis assignment.

Can Z and B execute one drilling block?

The tag is right; the binding is wrong is a useful diagnostic habit here: seeing a B-axis position proves that the control has an axis named B, but it does not prove that the active program path can coordinate it with turret Z. Axis ownership, channel assignment, interlocks, and machine-builder logic decide that behavior.

Run the decision test above the work with drills clear of both parts. Use reduced rapid and feed overrides, then command a small positive clearance move on one axis at a time. After direction is proven, test a small coordinated move. Watch both commanded and actual positions.

Two configurations can perform the work. A verified coordinated configuration can move Z and B simultaneously. A sequential configuration drills the main spindle and subspindle alternately. The sequential method is preferred here because it matches the demonstrated hand-coded approach, separates the feed conditions, and makes clearance and peck behavior observable.

Why is “twice the feed rate” not enough?

Drill diameter alone does not define an axis-speed ratio. Cutting speed determines spindle speed, while chip load determines feed per revolution. For inch units:

spindle RPM = (12 × cutting speed in SFM) / (π × drill diameter in inches)
axis feed in inches/minute = spindle RPM × feed in inches/revolution

Calculate the .187 in and .339 in operations independently from the drill manufacturer's cutting data, work material, tool material, and coolant conditions. If both spindles use the same surface speed, their required speeds differ because their drill diameters differ. Their linear feed rates also depend on the selected chip load for each drill.

Feed-per-revolution control adds another decision. A path may reference one designated spindle when converting feed per revolution into axis velocity. If Z is associated with the main spindle and B must follow the subspindle, one shared feed command may not provide independent chip loads. Use simultaneous motion only after the modal display or machine documentation identifies the feed-reference spindle for each axis or path.

Which check determines the programming method?

1. Position the turret at a clearance location and orient the two drills toward their intended spindles. Confirm that neither drill can contact a chuck, jaw, part shoulder, or the unused spindle during either approach.
2. Jog turret Z in the proposed cutting direction. If it approaches the main-spindle face in Z-minus, record the displayed sign and clearance coordinate. If it retreats, correct the programmed direction.
3. Jog B in the proposed cutting direction. If the subspindle approaches the west-facing drill in Z-plus, record that sign and its clearance coordinate. If not, correct the direction from the actual machine coordinates.
4. Test a small coordinated Z/B move above the work. If both axes interpolate, continue to the feed-reference test. If they sequence, alarm, or belong to different paths without synchronization, select sequential drilling.
5. Run each spindle and inspect its displayed speed and direction. Verify that each part rotates correctly against its stationary drill and that the opposite setup remains clear.
6. Compare commanded and actual axis motion at reduced override. If either axis lags, stops on an interlock, or references the wrong spindle for feed calculation, select sequential drilling.

How should the sequential pseudo-peck be programmed?

Hand-code the operation as explicit moves rather than inserting an unverified machine-specific canned cycle. The required sequence is:

1. Index the turret to the dual-drill station.
2. Move the B axis to the subspindle clearance position.
3. Feed the turret into the main-spindle work.
4. Retract the turret completely from the main-spindle work.
5. Feed the subspindle onto the opposing drill with the B axis.
6. Retract the subspindle completely from that drill.
7. Repeat steps 3 through 6 for the required pseudo-peck depth.

Give every infeed a defined endpoint and every retract a clearance endpoint. Alternate the operations only after the preceding drill is fully clear. This prevents one axis from changing the effective engagement of the other and lets each spindle operation use its own calculated speed and feed.

How is the cycle proved before production?

1. Run a graphics or path check if the installed control provides one, then execute above both workpieces with the spindles stopped.
2. Single-block the cycle at reduced rapid and feed overrides. Compare the sign and magnitude of each commanded move with the actual-position display.
3. Confirm that the main-spindle drill retracts before B begins its approach, and that B retracts before the next turret-Z peck.
4. Run each drilling side separately in material. Measure hole diameter and depth, then inspect chip formation and drill condition.
5. Run the alternating pseudo-peck cycle and verify that both axes return to their recorded clearance coordinates after every peck.

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