Checking Spindle Drawbar Force with Clamprite Spindle Drawbar Force Gage


Checking spindle drawbar force is economical and effective for discovering drawbar problems, maintaining good toolholder/spindle taper interface, maintaining tool life and part finish in a production machining environment.

Why Check Spindle Drawbar Force, Why Check for Spindle Drawbar Force Loss?

1. To preserve Spindle, Drawbar, Clamping Collet, Toolholder and Cutting Tool

Drawbar force is often the first thing to weaken or fail on a CNC Machining Center! If you check spindle drawbar force, or check drawbar force loss, there is an opportunity to know when drawbar problems need correction before a serious problem develops.

A stack of 100 to 150 Belleville springs provide the retention force that pulls the toolholder into the spindle taper. Belleville springs wear grooves into the drawbar and the friction between these springs and the drawbar can result in drawbar force loss, which can permit chatter, bad finish, reduced cutter life, and scrapped parts.

Also, Belleville springs can and do fatigue and break, resulting in extreme loss of drawbar force. Programmers will often compensate for this, unaware that one spring after another is failing.

With a reduced drawbar pull, the toolholder can be pulled out of the spindle taper during a cut, causing damage to the spindle taper, bearings, toolholder and pullstud, cutter, and fixture. A routine force check with a spindle drawbar force gage would reveal drawbar force loss, which would be the cue to initiate corrective action.

2. To maintain good Toolholder/Spindle Taper Interface, Maintain Tool Life and Part Finish

A toolholder that is held in place with near-specified drawbar pull will have a rigid interface with the spindle which will provide the best possible part finish. Tool life will be maximized and the spindle taper will remain accurate for the the maximum time.

How to order the Clamprite Spindle Drawbar Force Gage

Check our full webpage for gagehead sizes, spindle taper adapters – Spindle Drawbar Force Gage – or contact us just below