A Fresh Set of Eyes

Occasionally, a fresh perspective is needed to identify solutions to challenges.

Take, for instance, a situation encountered by one of our clients, a substantial job shop located in Orange County. They were facing difficulties in machining the internal diameter (ID) of a large part with a 2.48” ID, boring to a depth of 5.0” in 15-5 stainless steel. Initially, the task seemed straightforward, as the customer opted for a 1.25” anti-vibration bar with a positive rake DCGT style insert featuring two cutting edges. However, chip control issues persisted, leading to complications such as birds nesting inside the hole, requiring the customer to backbone to remove chips.

The starting parameters were set at 297 SFM, with a feed of .0035” IPR, taking two passes and resulting in the completion of 2 parts before the insert needed indexing, consuming approximately 7.15 minutes for the entire operation. Seeking a more effective solution, Darren, collaborating with our vendor partner - Aram Fundukian of Mitsubishi Materials, chose to reassess the approach rather than simply experimenting with a different insert geometry.

With a fresh perspective came fresh solutions. Transitioning to a 2” diameter boring bar, cutting to a 6” gauge length, and allowing for a direct mount to the turret significantly enhanced tool rigidity. A switch to a negative rake insert (DNGG) with 4 cutting edges provided added cutting strength and stability. Aram opted for Mitsubishi’s new “FS” chip breaker, designed specifically for challenging materials like nickel-based and other aerospace materials. The cutting speed was increased to 450 SFM, and the feed rate to .004 IPR. These adjustments effectively addressed the chip control issues. Additionally, machining in the direction of the chuck added rigidity, enabling the completion of the operation in a single pass, taking only 2.0 minutes.

Final results:
Initially, with the Original parameters, the customer achieved 2 parts per corner (4 parts total per insert), with an approximate cost of $3.75 per part in insert cost, requiring over 7 minutes plus additional tooling for completion.

Results with Mitsubishi’s Approach:
8 parts per corner (32 parts per insert), with an approximate cost of $0.47 per part in insert cost, and a mere 2 minutes to complete the operation. This translated to a remarkable 71% increase in productivity and 80+% savings in insert cost per part.

Let us bring a new set of eyes to your shop floor and experience “The S&D Difference” for yourself.