Service Home How To Procedures C-Axis Angle Head Drive - Installation - AD0853
Last updated: 05/02/2025

C-Axis Angle Head Drive - Installation

AD0853

Revision C - 5/2025

Introduction

This procedure tells you how to install the C-Axis Angle Head Drive.

Machine Compatibility:

  • VF-1/2/SS/YT
  • VF-3/SS/YT
  • VF-4/SS/-V
  • VF-5/40/SS/-V
  • VF-6/40/SS, 7/40, 8/40, 9/40, 10/40, 12/40, 14/40
  • VM-2/3/6
  • GM-2
  • 4th Axis Drive
     NOTE: Machines with a single-axis rotary installed require both 4th and 5th-axis drives. The C-Axis drive is not compatible with 2-axis rotaries. 
  • Software Version 100.21.000.1130 or higher
  • Sigma7 Motors

Required Tools:

  • Tool Holder
  • 0.0005" Dial Indicator
  • Mag Base
  • Allen Keys
  • Box Wrench Set
  • 3X Gauge Blocks OR Machinist Jacks with 1x Gauge Block.

This procedure applies to the following service kits:

  • 93-1001222: C-AXIS SPNDL HEAD KIT LGR MILL
  • 93-1001223: C-AXIS SPNDL HEAT KIT SML MILL
     NOTE: Not available to order until August 2025

Installation

1

If applicable, remove the previous version of the coolant ring. Loosen the two fittings [1] and disconnect the PCOOL Auxiliary supply line [2] and the Flood Coolant MAIN supply line [3]. 

2

Use a 5/32" allen key to loosen the coolant ring clamps [1].

Remove the previous version of the coolant ring.

Install the updated version of the coolant ring by placing it inside the clamps and hand tighten screws to hold it in place.

Attach the coolant hoses to the new ring, and tighten the fittings.

Screw in the side clamps first, then tighten the center last. 

3

Find the dimension of [A]:

Place a toolholder in the spindle and a mag base with an indicator on the table.

 NOTE: The HSK spindle face acts as the gage line, so no tool is needed for these spindles. The bottom drawing displays the HSK spindle, the top is applicable for BT and CT spindles.

Jog the spindle down until the indicator touches the underside of the tool flange face [1].

Zero the indicator and the Z operator position in the control.

Jog the Z-axis away from the indicator.

4

Jog the machine so that the indicator touches the underside of the spindle housing flange [1].

Jog the Z-axis until the indicator is zeroed.

Enter the operator Z value into the [A] dimension of the shim calculator, or write down this number. This value can be positive or negative.

 NOTE: Be sure to use the correct shim calculator based on your spindle configuration. 

5

Find the dimension of [B]:

Place 2 gage blocks on the table, roughly 3 inch (76.2 mm) apart.

Place a mag base with and indicator on the front of the spindle nose housing [1].

Jog down the Z-axis until the indicator is zeroed on the top of the right-side gage block [2].

Zero the operator Z-position in the control.

Jog the Z-axis out of the way and repeat this process on the left gage block. 

The change in height between gage blocks NTE: 0.0004".

6

Place the C-Axis drive onto the gage blocks so that the black adapter place faces upward. Do not place the outer housing [1] on the gage blocks.  The gage blocks should be mating with the C-Axis spindle surface [2]. 

7

Jog down over the top of the gage block that was zeroed out.

Jog in the Z-axis until the indicator is zeroed on top of the C-axis mounting flange [1].

Write down or enter the operator Z-value in the [B] dimension of the Shim Calculator, or use the formula below. The value can be positive or negative. 

Note: All measurements should be converted to millimeters before using the formulas below.

CT-40 Formula: [A] - [B] - 2 - 19.05 = [C]

BT-40 Formula: [A] - [B] - 2 - 27 = [C]

HSK63A Formula: [A] - [B] - 2 = [C]

8

Using the calculated value of [C]:

Take the shim pack out of the C-axis drive packaging.

Find a combination of shims that gets the closest to the [C] value.

The smallest shim increment is 0.004 inch (0.1 mm). Use calipers if needed to check the thickness of the shims.

 NOTE: The shim stack height should be within 0.1mm of the value of C. 

Install the shim pack in the C-Axis mounting flange [1].

9

Slide the mounting plate over the spindle nose. Check for any interferences with the flood coolant ring rail clamps.

If the fit is satisfactory, remove 4 of the 3/8" mounting screws [1] and mark each with an X.

Do not remove the two bolts that are closest [2] and farthest [3] from the operator.

10

Install the shim stack [1] on the mounting plate. 

Make sure that the two large cutouts in the shims are aligned with the two large thru holes on the mounting plate [2].

11

Slide the mounting plate and shim stack over the spindle nose. Use the provided longer length mounting bolts to secure the plate.

Tighten the plate until seated, then back off 1/8th of a turn.

12

Install a tool into the spindle that allows a mag base to be attached and place the mag with an indicator to the tool.

Check that the plate is concentric with the spindle axis. Touch off the indicator on the inner rim of the plate, as shown. 

Check the runout of the plate and use the set screws to adjust its position. 

Torque all of the bolts to 45 ft-lbs.

Remove the bolts closest and furthest from the operator and replace them with the provided bolts of longer length. 

13

Install the drive assembly:

Use the three aluminum stock blocks or the vice grip to prop up the drive on the table.

Ensure that the drive assembly is properly centered on the blocks or vice grip.

14

Lower the Z-Axis into the center bore until M8 bolts have thread engagement and it is lowered to the lip.

15

Thread in the M8 bolts to draw in the drive assembly to the mounting plate.

Tighten the bolts until seated.

Jog the Z-axis upwards.

Torque the M8 mounting bolts to 25 ft-lbs.

16

Before performing a tool change, remove the chip guard [1] from the tool changer enclosure by removing the four button-head screws. Replace the screws after removing the guard, to prevent chips from escaping. 

Electrical Installation

1

Remove the two button head screws [1] on the cable bracket located at the back of the enclosure of the machine.

2

Jog the X-Axis all the way to the right, and Y-Axis all the way back. Jog the Z-Axis down to the bottom of travel.

Route the conduit through the back of the enclosure [1]. Ensure the cable has enough slack, the cable should not be taut.

3

Plug Rotary Power Plug cable into plug labelled 4th Axis Power [1].

Plug Rotary Encoder Plug cable into plug labelled 4th Axis Encoder [2].

4

Press [SETTING].

Navigate to the Rotary tab. Find setting MILL SPDL C-AX-P20 [1]. Press [ENTER] to set axis [2].  

 

5

Set Axis Configuration to Axis C by pressing [C] [1].

Set Physical Connection to 4th Axis by pressing [4] [2].

Set Rotary Relation to Independent by pressing [I] [3].

Set Location to Tool by pressing [T] [4].

 

Load Angle Head Tools

NOTE: The following steps outline a general procedure for loading the angle head tool. Follow the manufacturer's provided instructions for your specific tool.

1

Press [ZERO RETURN] then press [C].

Handle jog the C-Axis and line up the center of the stopping block [1] with the notch closest to operator [2].

 [ZERO RETURN] again and jog C-Axis to line up the center of the stopping block [1] with the notch closest to operator [2].

 

2

Press [SETTING]

Navigate to the Rotary tab. Select the 4th axis [1] under Current Rotary Selections. Hit [ALTER] to set offsets. Select Set TC Offset [2].

Be sure the stopping block is aligned with the notch closest to the operator.

Zero-return the C-Axis to set it back to home.

3

Select [CURRENT COMMANDS].

Navigate to Devices > Mechanisms [1].  In the table, navigate to Main Spindle and press the right arrow button.

Press [F2] to orient the spindle [2]. 

Calibrate Angle Head Tools

NOTE: The following steps outline a general procedure for calibrating angle head tools. This process will vary depending on the design of the tool. Use these steps only as a general guide.

1

Jog the tool until the C-Axis is at 0 and the tool is pointed to the right. 

Loosen the screws at the base of the tool [1] so that the tool can rotate independently of the spindle. 

 NOTE: The angle head tooling pin should be oriented in this position before executing a tool change.

2

Place an indicator on the table and so that the needle is zeroed on the flat side on the back of the tool [1].

Jog the X-axis and check the parallelism of the tool.

Use a mallet to gently tap the tool to adjust until within the tolerance of 0.0005". 

Tighten the screws to lock the angle head into position. 

3

Handle jog the C-Axis to +90.

Check the parallelism on the same flat spot on the tool.

 

4

Take note of the C-Axis position.

Press [DIAGNOSTIC] to open the Parameters, Diagnostics and Maintenance menu.

Navigate to the Parameters > Compensation > C tab. Navigate to the 90.000 position in the C Axis Lead Screw Compensation table [1]. Enter the C-Axis value. 

NOTE: Send the C-Axis to zero using G28 on the control.

Zero return C, then manually jog the C-Axis back to 90 and check the parallelism again.

If it is not within tolerance, note the position then add it to the existing compensation. Re-check the parallelism.

5

Repeat step 6 for C-Axis positions at 180 and 270.