Shop improves Dental Surgical Tool Production with Microconic Over-Grip Collets

A Swiss CNC machine shop presented us with several problems related to long cycle times and poor tool life  with a high-volume group of  Dental Surgical Drills, Taps, and Counterbore Drills with standard ISO shank configuration.  

​These surgical components are made from 465 SS, 17-4PH, and Titanium.  The shop makes them complete with cutting edges on a Swiss-type CNC turning center. 

Due to the complexity of the cutting edge configurations, they are machined entirely on the main spindle, with the cutting edges out first. In all cases the cutting edges are larger in diameter than the shank.  

Before Microconic: The Workholding Problems

Before implementing the Microconic solution there were a number of problems:

• The cutting edges would be damaged by contact with the pick-off collet.
• All operations had to be performed in the main spindle because the part could not be held rigidly enough in the sub-spindle. This made for a very long cycle time.
• The milled flat and groove operations on the shank end had to be finished in the main spindle because of the lack of rigidity & lack of concentricity in the sub spindle
• The cut off tool took a beating due to the interrupted cut at the milled flat.  The cut off tool had to be sharpened or replaced every 60 pieces.
• Due to high tool maintenance and frequent adjustments, these jobs required a skilled setup person to run this product with little time to spend elsewhere. 

​After Microconic Cartridge & Over-Grip Collet:

Using the amazing Microconic over-grip collet, they were able to reach over the cutting edges of even the largest parts and chuck firmly on the shank.  This enabled a new world of cycle time reduction possibilities and new ways of machining the family of parts.

This enabled the use of the sub-spindle to perform the mill and groove operations, which became simultaneous operations in “shaded” time.  Cycle time was immediately reduced by 21 seconds per part.

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Operators immediately noticed that the Microconic system provided:

• Extremely Rigid chucking
• Better finishes
• Much Tighter Finished Part Tolerances
• Increased cut off & endmill tool life
• Live tools could be chucked short for more rigidity.
• Chucking damage was eliminated.
• Concentricity within .0002 TIR consistently
• Overall machine "up-time", or OEE (Overall Equipment Effectiveness) increased by 11%.

Using the Microconic system reduced the need for highly skilled personnel by greatly increasing tool life and stability.

Microconic over-grip collet opens 4mm larger than chucking diameter to reach over cutting edge area.

Summary:

• Overlap sub-spindle operations: Saved 21 seconds (9.2% cycle reduction).
• Savings of $79,300/year  (based on actual cycle time reduction alone).
• 7.2 weeks ROI (Return On Investment) for 3 Microconic cartridges & collets.
• Tool Life Increase: 500% (cutoff): was 60 parts per tool, is 300 parts per tool.
• Down time decrease.  OEE increased by 11%. 
• Increased lights-out production possible due to more predictable tool wear.
• Part quality increase

Although this ROI is fantastic with just the cycle time considered, in reality, it is far better with all of the intangible or untracked benefits listed above.  ​