Trunnion Mechanical Alignment

If the Trunnion is not enabled, follow the procedure on the [TrakMT Options] screen.

[Setup] → [TrakMT Options]

If the trunnion is being installed or its bolts are loose:

Position the trunnion in the correct mounting location.

Hand tighten the main mounting bolts so the trunnion is secured but still adjustable.

Lightly snug the adjustment block to hold position without fully locking it.

Set the X-Axis to 12 o’clock and reset the A-Axis to 0.

Position the dial indicator ¼” from the back edge of the platter using the Y-Axis.

Using the Z-Axis in fine increments, preload the indicator to 0.004”, then set the dial pointer to 0.

Move the Y-Axis toward 6 o’clock until the indicator is ¼” from the near edge of the platter.

Check the dial indicator readings at the 12 o’clock and 6 o’clock positions:

If both readings are 0 and the A-axis display on the control panel reads 0.000°, skip to Step 5 (the A-axis is already referenced correctly).

If they differ, proceed to Step 3.

Tilt the A-axis in fine increments until the dial indicator is midway between the start and end readings.

For example, if the start reading is 0 and the end reading is 0.002”, adjust the A-axis until the indicator reads 0.001”.

Reset the dial indicator to 0 and move the Y-axis back to 12 o’clock on the rotary table.

Check if the dial indicator still reads 0 (or within 0.0001”).

If the readings at both 12 o’clock and 6 o’clock are 0, the A-Axis zero position is found.

To set this position as the new 0, proceed to Step 4 for A-Axis referencing.

Step 4 is required only if you are adjusting and found 4th-Axis zero position from Step 3.

Set Manufacture Password.

Go to [Setup]→ [Mach. data] → [Axis MD] → [Select Axis] →[AX4:MA1] → [Search] for 34210.

Turn on the [JOG], [REF. POINT], and [4th Axis] buttons on the MCP.

Change Parameter 34210 to "1"

Press the "[+]" button on the MCP. The value for Parameter 34210[0] should change from "1" to "2" automatically.

The changing of the value to "2" means that the referencing process is complete.

For Reference: VMCsi - Reset Machine Absolute Zero for Each Axis

Move the dial indicator to 3 o’clock on the platter, positioning it ¼” from the edge.

Preload the indicator to 0.004” and set the dial pointer to 0.

Sweep the X-axis from 3 o’clock to 9 o’clock across the platter.

Observe the indicator reading at 9 o’clock to determine if deviation exceeds 0.0008”.

If adjustment is required, loosen the cradle support bolts on the high side to lower the cradle into the correct position.

If that does not correct the issue, shim the trunnion on the low side using twice the measured difference. After shimming, restart the process from Step 2.

Move A-axis to 0.000° (flat), mount a dial indicator to the spindle, and preload it on one edge of the platter slot.

Jog the X-axis across the slot (right to left) and rotate the C-axis until both ends read the same value. Record this C-axis position.

Tilt the A-axis to +90° or -90° (depending on Trunnion orientation) and repeat to obtain a second C-axis value.

Reverse the sign of both values, e.g., 0.082 → (–0.082), then calculate their average.

Go to [Setup]→ [Mach. data] → [Axis MD] → [Select Axis] →[AX5:MC1] → [Search] for 34090[0].

If 34090[0] is 0.000, enter the averaged result directly.

If 34090[0] already contains a value, subtract the old value from the new averaged result and enter that correction.

Press [Reset PO] to apply the new reference offset.

Tilt the A-axis to +90° or -90°, depending on the Trunnion’s orientation along the X-axis.

Set up the dial indicator as shown in the image.

In JOG mode, move the X and Z axes to position the indicator pointer vertically at the centerline of the rotary table, ¼” from the rightmost edge (3 o’clock position).

Slowly move the Y-axis to preload the indicator to 0.004”, then set the dial to zero.

Move the X-axis to the opposite (9 o’clock) side of the rotary table.

If the readings differ, loosen the left clamp and adjust the left side of the assembly along Y to correct.

Use adjustment screws 1 and 2 to fine-tune until deviation is ≤ 0.0001”.

Once aligned, tighten all clamps and torque both anchor blocks to 150 ft.lbs.

Position the dial gauge pointer as shown in the image.

Preload the indicator to 0.004” and set the dial pointer to 0.

Slowly rotate the platter 360 degrees, observing the + and - variations from zero.

Calculate the Total Indicator Reading (TIR) by finding the difference between the maximum and minimum values.

Ensure TIR does not exceed 0.002”.

If readings exceed the limit, inspect the platter mounting surface and flatness.

Continue to Trunnion Calibration