How to Replace a VMC/TMC Air Cylinder Kit

Before installing the upgraded Air Cylinder Kit, remove the current assembly.

Remove the front and right-side head covers to access the air cylinder (Photo 1).

Photo 1 shows the front cover off and a red arrow pointing to the right-side cover that still needs removal.

After cover removal, determine if the machine is:

CTS Equipped: Has a rotary joint with coolant and air lines (green arrow – Photo 2).

CTS Ready: No rotary joint; only an air blast line attached to a threaded rod and running through a support brace into the spindle (blue arrows – Photo 2).

For CTS machines: Disconnect the coolant hose and air line, then remove the rotary joint (left-hand thread).

For CTS Ready machines: Remove the lower support bracket and air line together, being careful not to bend it.

Remove socket head screws securing the clamp nut to the upper plate (Photo 2).

Unscrew and remove the clamp nut (left-hand thread). Remove the mounting nuts from the cylinder plate.

Shift the plate to the two right-side standoffs so it hangs outside the frame.

Unscrew and remove the air cylinder from the cage (left-hand thread).

Cut any cable ties as needed to move the cylinder and remove the cage (Photo 3).

Remove the old clamp plate and install the new Clamp Plate (P/N 3263041060). See Drawing 31889 in Photo 1.

Inspect the threaded rod for damage; replace with P/N 3202041090 if needed.

If replacing the rod, apply Blue Loctite 243 to the end that threads into the clamp/unclamp cylinder (left-hand thread). See Yellow Balloon in Photo 1.

Thread the Nut Air Cylinder (P/N 3263041050) onto the rod.

Thread it far enough to allow installation of the Clamp Plate-CTS-Top (3263041060), Wave Disk Spring Washer (50240308), and Clamp Nut (3202041100).

Install one M5-0.8x30 SHCS through the clamp nut and into the clamp plate.

Tighten the nut and plate fully, then back off 1/4 to 1/2 turn until the SHCS can reach the upper lock nut.

Install the remaining 3 screws and leave them slightly loose for now.

Reinstall the cylinder and new Air Cylinder Kit onto the large standoffs.

Tighten the mounting nuts securely.

For CTS machines, reinstall the rotary joint (leave fittings off for now).

Adjust the Air Cylinder Kit so there's a 5mm gap between the kit and the spindle.

Tighten the 4 SHCS in the lock nut with no rotational movement in the assembly.

There should still be a slight pivoting motion between the clamp plate and lock nuts for self-alignment.

Note: The 5mm gap is an initial adjustment, it may need to be adjusted further in the next step.

Clean the spindle taper to ensure it’s free of coolant and debris.

Clean a flat spot on the table and place the Bump Out Tool Setting Gauge small-end down.

Verify that both the gauge and bump out tool tapers are clean.

Insert the bump out tool into the gauge and zero the indicator.

Record the small needle position on the indicator for reference.

Press and hold the spindle Unclamp button, then insert the bump out tool into the spindle.

Measure bump out—it should read between 0.020" and 0.030". Compare small needle position to the gauge setting.

If adjustment is needed, loosen the 4 clamp screws, rotate the assembly, then reapply 243 Loctite and tighten.

For CTS machines: Reinstall the rotary joint onto the spindle (left-hand thread).

Reconnect the air and coolant fittings, followed by the lines.

For CTS Ready machines: Reinstall the air tube and support bracket carefully to avoid bending.

Reinstall the air tube and support bracket together, being careful not to bend the tube.

Replace any tie wraps cut during disassembly.

Confirm all hardware is securely fastened.

Reinstall the front and right-side sheet metal covers.

Clean the machine to complete the installation.