Скачать или смотреть Power Drawbar Upgrade Installation | R8 / TTS CNC Mill

In this video, I walk through the step-by-step installation of a power drawbar assembly on an R8 spindle CNC mill.

We start by installing the drawbar and correctly stacking the disc springs in the proper triple cup, edge-to-edge configuration. Getting this spring orientation right is critical for consistent clamping force and long-term reliability.

From there, I:

Slide the drawbar through the tophat and spindle

-Install the R8 TTS collet, aligning the keyway with the spindle alignment pin
-Hand-tighten the drawbar into the collet to hold everything in place
Insert a TTS tool holder into the spindle

Using a factory spindle pin wrench, I hold the lower spindle while tightening the drawbar from the top, gradually compressing the disc springs. During tightening, I repeatedly test-fit the air cylinder assembly to ensure proper clearance between the piston and the top of the drawbar.

Once I reach approximately 0.010” of clearance, I move on to installing the air-operated power drawbar cylinder:

-Slide the cylinder assembly into place from the front
-Install the two shoulder bolts with retention springs
-Carefully start the fasteners by hand to avoid cross-threading
-Tighten both guide bolts evenly to maintain alignment with the spindle

These shoulder bolts act as alignment guides while the springs help keep the drawbar properly seated during machine operation.

This is a critical upgrade if you’re running TTS tooling and want faster tool changes, consistent clamping force, and less wear on your spindle.

🧠 Topics Covered

Power drawbar fundamentals

Proper Belleville spring stacking

R8 / TTS collet alignment

Drawbar preload and clearance setup

Air cylinder installation tips

If this helped you, like, subscribe, and comment with your CNC setup or questions. I’m documenting this entire machine upgrade step by step.