Draw Bar force testing equipment Dynamometer
Draw bar force gauge or Dynamometer is used to measure clamp force of spindles. 30,40,50 taper machines and many other types of spindles. Indications of low spindle drawbar clamp force Chatter Repeatability problems Degradation of tool life Poor surface finish Thrown tool from spindle Wear around outside edge of taper from tool walking out during cut Retention knob wear

Machine problems that can cause low spindle clamp force

1. Broken Belviews or springs on the drawbar
2. Coolant or debris contamination causing excessive friction
3. Tool retention fingers worn
4. Spindle taper has been reground causing tool to sit deeper in spindle
5. Draw bar shaft worn from belviews rubbing on the main shaft
6. Retention knobs of tools worn

What kind of damage can low spindle clamp force cause?

• Damage to spindle-must be replaced

• Damage to machine and waycovers when the tool lets loose or the retention knob fatigues and breaks.

• Injury to an operator!! That tool holder can many times find a hole around a pallet changer and go through to the setup station or go through a window.

• Damage just about anything when that tool is spinning at 10,000 plus RPM.