Warning About Unlicensed Tool Holders
CAUTION! Using unlicensed BIG-PLUS® tooling can cause spindle damage!
BIG Daishowa Seiki CO Ltd. recommends the use of only genuine BIG-PLUS® tooling in your BIG-PLUS® spindle system.
The BIG-PLUS® system was developed by BIG Daishowa Seiki to provide the ultra-high rigidity, concentricity accuracy, and exact repeatability necessary for ultra-high precision machining. Since then, BIG-PLUS® has become the gold standard for spindle systems, as more that 100 of the world’s best machine tool and spindle builders have become BIG-PLUS® licensees.
Why do BIG DAISHOWA SEIKI and its licensees receive universal praise and recognition for performance?
The answer is found in the simultaneous dual contact system that ensures much higher rigidity through exceptionally tight contact not only between the BIG-PLUS® spindle and the taper of the BIG-PLUS® tool holder but also between the flange face of the BIG-PLUS® tool holder and the BIG-PLUS® spindle face. In order to achieve this ultra-precise contact, the 100+ spindle builders licensed by BIG Daishowa worldwide have each committed to use the master spindle gauges and measuring devices produced and controlled by BIG Daishowa.
These gauges assure strict compliance of all genuine BIG-PLUS® spindles made by BIG Daishowa and its licensed manufacturers around the world. The most important gauge is the "Master Gauge", as it provides traceability to the original Master held by BIG Daishowa in Japan. The measuring device, once calibrated to the master gauge, ensures that the spindle face location is precisely located to the gauge line diameter of the spindle taper to the appropriate tolerance.
With the popularity of BIG-PLUS® spindles comes the need for genuine BIG-PLUS® tooling. As with the BIG-PLUS® spindle, the tooling to be used in that spindle must be produced and controlled with an ultra-precise flange face located and measured in proper relationship to the gauge line of the taper. With official BIG-PLUS®gauges traceable to BIG Daishowa's Master Gauge, a quality tooling manufacturer can produce to the BIG-PLUS® specification.
However, it also requires the know-how of BIG Daishowa to help train the licensed manufacturers of tool holders in order to ensure that all holders are produced to the same tolerances at every production site. Only in this way can users have confidence that any of the machine tools they purchase for use in a BIG-PLUS® spindle will work to the higher performance levels needed for ultra-high precision machining.
Unfortunately, some unlicensed tooling companies have manufactured and marketed tool holders for use in BIG-PLUS® spindle systems. Do not be fooled and assume that an unlicensed tool holder that "fits" a BIG-PLUS® spindle has the required tolerances to perform as well as genuine BIG-PLUS® tool holders. Makers of "will-fit" tool holders simply do not have access to properly licensed gauges, know-how, system dimensions, and tolerances from BIG Daishowa, and purchasers of those products risk problems arising from performance, premature spindle wear, or accidents.
Unless all the tools are marked "BIG-PLUS® Spindle System-Licensed BIG DAISHOWA SEIKI", the use of tooling not made by BIG Daishowa or its licensees may result in unsatisfactory performance and/or damage to very expensive spindles.
Conditions producing such unsatisfactory performance include:
- Distance between flange face and gauge line diameter more than specification — little or no face contact occurs; tool holders provide only taper contact and no benefit of BIG-PLUS®.
- Distance between flange face and gauge line diameter less than specification — face contact only; tool holders "float" in spindle taper with no positive radial location. Large cutter runout and fretting corrosion on spindle face occurs immediately. Severe spindle damage will occur.
- Gauge line diameter less than specification; face contact only with minimal or no taper contact. Severe spindle damage can occur.
- Gauge line diameter more than specification; taper contact only and no benefits of BIG PLUS®