Questions with Michael Herman

1. What do I need to keep in mind about my machine and spindle?

When choosing a spindle and tool holder, you want consistent results and long service life. In the BIG-PLUS spindle system, the shank contacts the spindle taper and spindle face simultaneously. The margin between the two is smaller and the contact area between the flange and spindle is larger. This increases rigidity, which has implications for everything from ATC repeatability to boring smoothness. It also reduces fretting corrosion and eliminates Z-axial movement at high speeds, vastly extending overall tool life.

One caveat – you’ll only get BIG-PLUS benefits from licensed BIG-PLUS spindle systems. BIG-PLUS spindle dimensions are strictly controlled by the BIG DAISHOWA Master Gage and meant to work with BIG-PLUS licensed tool holders. Unlicensed holders may fit the spindle, but they aren’t guaranteed to reach peak performance.

2. My milling chucks aren’t meeting expectations. What are my options?

With milling chucks, pullout is a major issue, particularly when machining heat-resistant super alloys such as titanium or Inconel. In demanding applications, there’s a need for guaranteed security against pullout to ensure there’s no damage to parts or delays in manufacturing.

The Mega Perfect Grip, with fully concentric clamping, combines the accuracy and cutting performance of heavy-duty milling chucks with the security against pullout of solid side-lock tool holders at runout less than 0.0004" at 4xØ. It accepts industry standard Weldon flat milling cutters (ASME B94.19-1997) and no special milling cutter grinding is required. A lock mechanism using a key grip prevents the slip and pullout of the tool during heavy cutting.

3. Which tool holder provides the best accuracy in tight spaces?

Hydraulic chucks are ideal tool holders for high-precision, high-accuracy machining. Instead of relying on a nut, collet, or extreme temperature to clamp the body of a tool, hydraulic chucks use fluid. By expanding an internal membrane in the holder body, the hydraulic fluid applies uniform pressure around the cutting tool. The evenly applied gripping provides more control and consistency than a collet or manual tightening of a nut.

Hydraulic holders are useful in low clearance, tight work envelopes because of their relatively slim design. They allow a further reach into mold cavities or other tricky work envelopes with less interference and without using extensions that can sacrifice rigidity. These characteristics are effective in delicate 5-axis machining, finishing especially.

4. What role does digital boring play in efficiency?

Precision boring operations are often done last, so scrap due to oversize holes means hours of lost work. With demanding requirements, the difference between a good aerospace part and a scrapped one can be just a few tenths of an inch on a bore.

Boring heads, such as our EWE product line, include digital readouts that, with the help of solid-state magnetic scales, display the actual diameter of the tool instead of hard-to-read Vernier markings. These heads make adjustments in the machine much simpler and reveal any backlash at the adjustment screw. They can also pair with a mobile app via Bluetooth so adjustments can be tracked and saved; reduction of human error, speedier adjustments, and readily available wear and setup histories are just a few of the benefits of this arrangement.

The next phase is closed-loop boring. The EWA fine boring head has a built-in motor that moves the cutting edge to the proper diameter automatically via remote Bluetooth commands, eliminating the time and risk associated with the machine operator manually adjusting the boring head by hand.

BIG DAISHOWA Inc.