2. ATC Spindle Setup

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Spindle Installation & Drag Chain Setup

Spindle & Drag Chain Arm

1. Start by unpacking the ATC spindle and grabbing the ATC drag chain arm. We will also need 6 x M4 – 8mm flat head screws and the Allen key from the ATC fasteners bag.

2. Lift the spindle out of the bottom foam and place it on the top foam packaging with the threaded mounting holes facing up.

   
   

   ⚠️ Never stand the spindle on its nose (tool end) to avoid damaging the bearings.  

3. Remove the male end link (studded end) from the Z-axis drag chain.

4. Attach this end link to the ATC drag chain arm, minding the mounting position and direction, using two (2) M4 – 8mm screws.

   
   

5. Mount the drag chain arm to the spindle using four (4) M4 – 8mm screws.

   
   

Mounting Plate

1. Place the ATC mounting plate onto the spindle.

2. Select the correct mounting position based on your machine configuration.

   4×4 & 2×4 Machines the standard configuration is the center position. The mounting plate holes should align up with six (6) corresponding holes on the spindle.

   
   

   4×8 Machines the mounting plate should be shifted up. The mounting plate holes will align with the top four (4) holes on the spindle.

   
   

3. Secure the mounting plate using M6 – 14mm button head screws.

Mount the Spindle

⚠️ Due to the weight, we recommend two people to mount the ATC spindle.

Identify Your Gantry Plate

Look at your Z-gantry on your AltMill and compare to the image below.

If your Z-gantry has the orange circled hole pattern, follow the 6 Screw Installation.

If your Z-gantry has the blue circled hole pattern, follow the 4 Screw Installation.

Mount the Gantry

6 Screw Installation

Most newer machines should have this hole pattern in the gantry. For improved stability, we recommend this installation if you have the gantry for it.

Grab:

• Two (2) M6 shoulder screws

• Three (3) M6 – 25 mm button head screws

• One (1) M6 – 14 mm button head screw

1. Thread the M6 – 14 mm screw into the hole (marked #1) in the image below. Leave about 7 mm (1/4 in) sticking out. Hang the ATC spindle on this screw using the mounting slot. This acts as a temporary anchor — do not tighten.
2. Install the two (2) M6 shoulder screws in the lower holes, marked #2 and #3. Start by hand, then tighten fully, in the order listed.
3. Install the two (2) M6 – 25 mm button head screws in the lowest mounting holes. Start by hand, then tighten fully.
4. Install the final M6 – 25 mm screw in the upper left hole, and tighten it fully.

4 Screw Installation

Grab:

• Two (2) M6 shoulder screws

• Two (2) M6 – 25 mm button head screws

1. Hold the ATC spindle against the X-axis gantry. Install the two (2) M6 shoulder screws in the lower holes, marked #1 and #2. Start by hand, then tighten fully.
2. Install the two (2) M6 – 25 mm button head screws in the lowest mounting holes. Start by hand, then tighten fully.

Drag Chain Hardware Installation

This section will modify the 4×4 and 2×4 AltMills to make them compatible with the Z-axis drag chain.

4×8 Machines

SKIP AHEAD TO CABLE AND TUBING ROUTING

4×4 & 2×4 Machines

Remove the Drag Chain Bracket

1. Disconnect the X-axis drag chain from its end link on the bracket.
2. Remove the old drag chain bracket from the back of the gantry.

3. Separate the one (1) end link from the old drag chain bracket, we will use it.

   
   

Install the Z-Plus Drag Chain Bracket

1. Remove one (1) end link from the Z-axis drag chain

2. Install the two (2) end links on the new Z-plus drag chain bracket, by using M5 – 10mm screws and M5 lock nuts. Only use 3 of each for now, to ease cable routing later on.

   Tip: Ensure the male and female drag chain ends are correctly oriented; reversing them is tedious.

   
   

3. Install the Z-Plus drag chain bracket back onto the XZ carriage.

   
   

Cable and Tubing Routing

Prepare the Cables

Gather the following from the ATC box:

• Signal cable
• Pneumatic tubing (10 m)
• ATC spindle cable (blue connector) – if it’s already installed on your AltMill, that’s great!

Place the cable ends and tubing near the spindle connections on the Z-axis.

Route Through the Z-Axis Drag Chain

1. Route the wires and tubing through the opening in the Z-plus drag chain bracket. If it’s tight, loosen the bracket slightly to widen the opening.
2. Use a flathead screwdriver to detach the remaining clips on the Z-axis drag chain.
3. Clip the Z-axis drag chain back onto its end links.
4. Close the clips around the three cables.
5. Use one M5 – 10mm screw and M5 lock nut to fasten the loose end link at the Z-plus drag chain bracket, from the previous section.

⚠️ Important: Keep cables and tubing parallel inside the drag chain & do not cross them

Connect the Spindle

On the ATC spindle, connect the following in this order:

1. Spindle cable

2. Signal cable

3. Pneumatic tubing

   ⚠️ Ensure connectors align with the grooves on the aviation plug; misalignment may damage pins.

Route Through X and Y Drag Chains

1. Detach the X-axis drag chain from the end link on the XZ carriage. Open the clips, place the new cables and tubing inside, and close a few clips to hold them in place.

   • Run the tubing under the Z-plus drag chain bracket, before entering the X-axis drag chain. Leave some tubing out for strain relief.

   • Run the spindle and signal cables straight from the Z-axis drag chain into the X-axis drag chain

   • Make sure these do not cross or twist.

   
   

2. Adjust the cables and tubing as needed, then close the remaining clips along the X-axis drag chain.

3. Reconnect the X-axis drag chain to the Z-plus drag chain bracket.

4. Verify the spindle cable reaches the VFD through the table leg cutout.

5. Verify the signal cable reaches the SLB-EXT.

6. Ensure the tubing is free of kinks and sharp bends.

7. Finally, route cables and tubing for the Y-axis drag chain, adjust as needed, then close the clips.

Congrats! You’ve completed the spindle setup steps.