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.  

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. 

Matt goes on to explain how the Microconic System solves all of the problems with traditional pickoff collet with a   guaranteed 0002" TIR accuracy and ships everything from stock within two days of placing an order!

Masa Tool's Microconic cartridge is made of exotic high-chromium tool steel, triple tempered and cryogenically treated to provide stable construction.  All functional seating surfaces are ground with extreme precision on a one-piece, ultra-rigid body structure.

“The cartridge can be used as a calibration gage to verify the machine spindle accuracy,” Co-owner Chip Prescott notes.

Microconic collets are finished to exacting standards with a five-step grinding process that removes the effect of heat-treat warpage. Also, the proprietary Microconic form of the closure surfaces is inherently more accurate than traditional collets, providing for a greater full-accuracy working range.
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Cartridges are available to fit in push-type dead-length collet closers and also draw-type closers: F20M10 (for TF20 collet replacement), F25M10 (for TF25 collet replacement), and 5CM10 (for 5C collet replacement). All of these cartridges use the same Microconic UM10 collets, with more cartridge sizes in development to be released soon.

Matt Saccomanno, the Co-Founder of Masa Tool and inventor of the Microconic Workholding sytem will talking about process innovations in the metalcutting manufacturing industry during the International Manufacturing Technology Show, IMTS, in September at McCormick Place in Chicago, IL. 

Swiss-type CNC machines have gained in capability and demand as the machined components they produce are trending toward higher precision and micro-sized features. As the machines have become more sophisticated, the underlying basics of workholding remained unchanged until recently.

​This presentation is an overview of new developments as well as traditional approaches with relevance to today’s highly capable sliding headstock “Swiss-type” CNC turning centers. The goal is to summarize best-practices for optimizing use of both main and sub-spindle to maximize productivity and overall equipment effectiveness. The material presented is useful for machinists, CNC programmers, tool crib personnel, manufacturing engineers, estimators, and hands-on managers.

If you would like to reserve your spot in this technical presentation and discussion please click the below button.

Set ups are quicker and more repeatable with Microconic™. You can document the micrometer-adjust collet closure in your set up plan so it's done the same every time, regardless of operator skill and without relying on "feel". ​

State-of-the-art LFV is a widely applicable cutting technology designed to avoid the problem of spiraling chips, entanglement of chips and built-up edges. Benefits include increased cutting tool life, reduced heat generation and reduced power consumption. 
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The popular Citizen CINCOM L20 series sliding headstock lathes are now available with Low Frequency Vibration (LFV). 

This widely applicable cutting technology – able to handle a broad range of machining shapes and materials – is ideal for cutting difficult-to-cut materials.  The state-of-the-art LFV suppresses various risks associated with these materials, such as entanglement of chips and built-up edges.

Depending on the material being cut, a variety of problems can be caused by chips getting entangled with each other, including increased cutting resistance, scarring, changes in the texture of the machined surface, tool nose damage, and built-up edges due to cutting heat.  In LFV cutting, “air cutting” time prevents the machining temperature from rising, which both prolongs tool lives and gives relief from various problems caused by chips.

Masa Tool is introducing its Microconic workholding system for use in subspindle Swiss-type machine operations, enabling the operator to switch operations from the main to the subspindle so that usage is balanced. This capability is said to reduce cycle time in ways that are not possible with conventional collets.

​The Microconic system consists of two primary components: a cartridge that fits in the machine’s standard TF20, TF25 or 5C collet closer, and the collet itself, which fits into the cartridge. Each cartridge model has a solid extended nose and can accept both regular and over-grip collets. The over-grip collets open up to 0.157" (4 mm) larger than the clamping diameter.

​The Microconic cartridge’s extended nose design directs all of the chucking pressure directly over the workpiece for concentricity and rigidity. Total indicated runout (TIR) for the Microconic system is guaranteed at 0.0002" (5 µm) at the workpiece, absent any runout introduced by the machine structure or other elements of the setup. The system capacity ranges from 0.008" to 0.394" (0.2 to 10 mm) in diameter, with all sizes available from stock.

We got a very unexpected present in the mail this past week! We where very excited to learn that our Microconic workholding system for small diameter part machining was featured in the Rapid Traverse section of the June 2017 issue of Modern Machine Shop!!!

We've got pictures of the article below in case you don't currently subscribe to Modern Machine Shop.  You can also download a PDF copy of the entire June issue below in the link. It starts on Page 25 of the PDF download.  If you have the print edition it's on Page 22, or you can just read thought the screen shots below.  

We want to really extend a very big THANK YOU to Matt Danforth at Modern Machine Shop who wrote this article.  Matt really did an awful lot of work learning about the various features of our system. We know there where many many hours that he spent to develop this story just from the sheer number of follow up questions and conversations.  We really have an awful lot of respect for the entire MMS team and the effort they put into getting their story's "just right".

Workholding Advances
Medical parts are often delicate, which can create problems when they are picked off with the subspindle for backwork. It is important but difficult to apply just the right amount of pressure to hold the part in the subspindle. And once the optimum gripping force is determined, it is not easy to communicate to other operators how the adjustment was made.

​Machine tool accessory maker Masa Tool Inc. (Oceanside, CA) has developed a collet system that makes this process easier. The collet is set using a special tool with marked graduations that enable precise adjustments to the gripping force of the collet.

“You can document the micrometer-like adjustment for the collet closure in your setup plan,” said Matt Saccomanno, CEO.  “It’s done the same way every time, regardless of operator skill and without relying on feel.”

One of the more challenging Swiss applications is making dental implants because of their small size. Saccomanno said that Masa recently helped a customer broach a dental implant on the subspindle with the Masa collet system holding only a small land. Considering how much force is applied to the workpiece during a broaching operation, this might have seemed impossible to accomplish.

The reason it is possible is that the Masa collet system applies the gripping forces directly over the area where the collet grips the part. The collet system has two main parts, a cartridge that replaces the standard machine collet and a smaller collet made by Masa that is installed into the cartridge. These components are held to a high accuracy and are made by Masa with proprietary grinding methods. Concentricity variation is held to 0.0002″ (0.005 mm).

“This particular broaching application used an over-grip collet,” Saccomanno said. “The process change moved an operation from the main-spindle to the subspindle and so allowed some simultaneous machining not possible previously. Before they used our system, the part was made entirely on the main spindle.”
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An over-grip collet opens up to pass over a shoulder or some other feature on a part in order to grip the part past the shoulder. Masa makes over-grip collets that can open up to 4 mm over the chucking diameter. This is the largest difference in diameter in the industry and still holds 0.0002″ TIR, according to Masa.