Draw Bar force testing equipment Dynamometer
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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 drawbar force
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Chatter
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Repeatability problems
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Degradation of tool life
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Poor surface finish
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Thrown tool from spindle
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Wear around outside edge of taper from tool walking out during cut
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Retention knob wear
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Machine problems that can cause low spindle clamp force
- Broken Belviews or springs on the drawbar
- Coolant or debris contamination causing excessive friction
- Tool retention fingers worn
- Spindle taper has been reground causing tool to sit deeper in spindle
- Draw bar shaft worn from belviews rubbing on the main shaft
- Retention knobs of tools worn
What kind of damage can low spindle clamp force cause?
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Damage to spindle-must be replaced
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Damage to machine and waycovers when the tool lets loose or the retention knob fatigues and breaks.
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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.
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Damage just about anything when that tool is spinning at 10,000 plus RPM.
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