How to Replace a VMC/TMC Air Cylinder Kit

Before we can install the upgraded Air Cylinder Kit on the VMC/TMC machines we need to remove the existing assembly. The following steps will cover the removal of the existing parts.

To get to the Air Cylinder Kit you need to remove the front and right side Head Covers. Photo 1 shown with front cover removed and red arrow pointing to the right side cover that still needs to be removed.

Once the covers have been removed you need to determine if the machine has Coolant Through Spindle or if it is just CTS Ready(Coolant Through Spindle ready). The following (2) bullet points will show the difference between CTS and CTS ready.

Machines that are equipped with CTS have a rotary joint attached to the spindle with a coolant and air line attached to it. The green arrow is pointing at the rotary joint. See Photo 2.

The CTS ready assembly doesn't have a rotary joint it just has an air blast line that is attached to the threaded rod in the cylinder and then goes through a support brace and into the spindle at the bottom of the assembly. The blue arrows are pointing to the air blast line and support brace. See Photo 2

This step covers both CTS and CTS Ready machines. The red bullet point covers machines that have CTS installed and the orange point covers machines that are CTS ready.

To remove the existing Air Cylinder from a machine that has Coolant Through Spindle, first disconnect the coolant hose from the rotary joint, then remove the air line and fittings, and then finally remove the Rotary Joint. See Photo 1

Note: The rotary joint has a left hand thread.

To remove the Air cylinder kit on machines that are CTS Ready first remove the screws from the Lower Support Bracket then loosen the Airline that goes from the cylinder to the spindle and then remove both pieces together. Try not to bend the Air Line. See Photo 1

Next remove the socket head cap screws that go through the clamp nut into the upper plate of the Air Cylinder Kit assembly. Then remove the clamp nut. See Photo 2

Note: The Clamp Nut and Clamp Plate have a left hand thread that attaches it to the threaded rod on the cylinder.

Finally loosen and remove the nuts that hold the cylinder mounting plate to the large standoffs. Now remove the assembly and reattach it to the two right side standoffs so it hangs outside of the 4 standoffs. Now you can remove the Air Cylinder Kit from the the air cylinder, again this is a left handed thread. See Photo 3

You may need to cut some cable ties on cables, air or oil lines to be able to move the air cylinder to remove the cage from it.

With the old Air Cylinder Kit removed from the cylinder remove the clamp plate and replace it with Clamp Plate (P/N 3263041060). See Drawing 31889 in Photo 1.

Once the Clamp Plate has been replaced on the Air Cylinder Kit you should inspect the threaded rod in the cylinder and replace it if the threads are damaged (P/N 3202041090).

If the threaded rod is replaced use 243 (Blue) Loctite on the end that threads into the Clamp/Unclamp Cylinder. See Yellow Balloon in Photo 1

Note: The threaded rod has a left hand thread.

Next attach the Nut Air Cylinder (3263041050) to the threaded rod on the cylinder. Thread it up far enough that the Clamp Plate-CTS-Top (3263041060),Washer Wave Disk Spring (50240308), and Clamp Nut (3202041100) can be installed to the threaded rod as well.

Install one of the M5-0.8x30 SHCS through the lower clamp nut and into the Clamp Plate. Tighten the Clamp Plate and Nut until it stops against the upper lock nut. Slowly loosen until the SHCS can be threaded into the upper lock nut (approximately 1/4 to 1/2 a turn). Then install the other 3 screws. Leave slightly loose for now.

Reinstall the cylinder with new Air Cylinder Kit parts onto the large stand-offs and tighten the nuts.

Once the Cylinder has been reinstalled on machines that have CTS, reinstall the rotary joint. Don't reinstall the fittings just yet.

Adjust the Air Cylinder Kit Assy so that there is a 5MM gap between it and the spindle, and tighten the 4 SHCS in the lock nut. There should be a slight amount of movement between the Clamp Plate and the Upper and Lower Lock Nuts even with the screws tight. This is by design.

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

You should now clean the spindle taper to insure that there isn't any coolant or debris in the spindle.

Next clean a spot on the table and set the Bump Out Tool Setting Gauge on the table small diameter down. Verify the taper of the setting gauge and setting tool are clean. Place the setting tool into the gauge and set it so it reads zero. It is important to record the position of the small needle on the indicator as well.

Place the setting tool into the gauge and set it so it reads zero. It is important to record the position of the small needle on the indicator as well.

Next press and hold the Unclamp button on the the spindle and insert the Bump Out Tool into the spindle and measure the bump out with the gauge. The bump out should be between 0.020" and 0.030". Be sure to check the position of the small arrow and compare it to when is was in the Gauge Setting Tool.

If the Air Cylinder Kit needs adjusting, loosen the 4 clamping screws and rotate the Air Cylinder Kit up or down until the correct bump out is achieved. Once the correct bump out has been achieved add 243 blue Loctite to the clamping screws then tighten.

This step covers both CTS and CTS Ready machines. The red bullet point covers machines that have CTS installed and the orange point covers machines that are CTS ready.

On machines that have CTS: Once the Cylinder has been reinstalled on the large standoffs reinstall the rotary joint. Next reinstall the air and coolant fittings and then the air and coolant lines.

Note: The rotary joint has a left hand thread.

For CTS Ready machines reinstall the Air Tube and Support Bracket together trying not to bend the Air Tube. Next attach the compression fitting to the threaded rod on the Clamp/Unclamp cylinder and tighten.

Reinstall any Tie wraps that were cut so the Clamp/Unclamp cylinder could be moved to replace the Air Cylinder Kit.

Reinstall the front and right side sheet metal covers and clean machine.