Turning, micro-milling, micro-drilling, micro EDM, micro- WEDM, micro ECM, etc. ultra-precision machining, electrolytic in-process dressing and grinding.

What is Micro-Machining Micro machining is one of the key technologies of micro engineering. Micro engineering can be defined as the branch of engineering that deals with development and manufacture of products, whose functional features or at least one dimension is in the order of microns However, there is no universally agreed distinction between macro and micro-scale machining. Micro machining processes are categorized according to the machining phenomena and characteristics contemporary level of conventional technologies, person perspective machining method, type of product or material. micro in micro-machining indicates ‘micrometer’ and represents the range from 1 µm to 999 µm. Scientific Technical Committee of the Physical and Chemical Machining Processes of CIRP, 1 to 500 µm was adopted as the range for micro machining

The term “micro machining” is now associated with the qualities of precision and ultra-precision machining.

Need of Micro-Machining Processes The last two decades have shown an ever-increasing interest in higher precision and miniaturization in a wide range of manufacturing activities. These growing trends have led to new requirements in machining, especially in micromachining.

Types of Micromachining Process There are two basic groups of micromachining process: mask based and tool based micromachining. The mask based technology has the limitations of fabricating 3D structures as it is applied only to two dimensional shapes processes using tools, especially those using solid tools, can specify the outlines of various 3D shapes owing to the clear border at the tool surface and the easily defined tool path

Types of Micromachining Process

The manufacturing technologies connected with micro products of silicon are relatively highly developed compared to that of metals, polymers and ceramics From a geometrical point of view, micro products can be organized in to three groups: • Two-dimensional structures (2D), such as optical gratings. • Two-dimensional structures with a third dimension (21/2 D), for example fluid sensors. • Real three-dimensional structures(3D), such as components for hearing aids Micro engineering deals with development and manufacture of products, whose functional features or at least one dimension are in the order of µm. The products are usually characterized by a high degree of integration of functionalities and components.

Micro-cutting process uses physical cutting tools in high precision CNC machines to fabricate parts with micrometers features and sub-micrometer tolerances. An advantage of this process is the ability to use any machinable material, quick process planning and material removal, and three-dimensional geometry only limited by the machine tools used. Disadvantages are that forces are placed on micro cutting tools causing deflection and possible breaking. Deflection reduces process precision and tool breakage results in repeated set up, slower production, and poorer tolerances

Turning microparts can be difficult work Turning microparts can be difficult work. Not only are tolerances and finish requirements generally tighter and finer for parts with ¼" and smaller diameters, secondary operations are often required for medical and aerospace parts. In addition to turning, this raises concerns about how to hold, mill, cross-drill, deburr and inspect the parts. Even finding the parts in the chip tray after cutoff can be a challenge.

It is a conventional material removal process that has been miniaturized. During machining, instructions to the miniature machine controller were supplied as numerical control (NC) codes which were generated by SLICER and TAPER TURNER for straight and taper microturning process. Optical Microscope Scanning Electron Microscope Ultrasonic Cleaning Unit

Many shops have turned to Swiss-style, sliding-headstock lathes for this type of work. Swiss-style machines are generally equipped with higher-speed spindles than conventional CNC lathes, which is half the battle when turning microparts. Machinery’s Handbook states that turning a 1?8"-dia. 304 stainless steel part at 200 sfm means revving a spindle to 6,400 rpm. For softer materials, such as aluminum or brass, speed requirements are even higher. And the problems you’ll encounter with insufficient spindle speed are many, including poor surface finish and built-up edge, which leads to tool chipping. Most conventional CNC lathes max out in the neighborhood of 3,000 to 5,000 rpm, while Swiss-style machines hit main spindle speeds of 10,000 rpm or higher. When it comes to microparts, most conventional CNC lathes just can’t cut it. But there’s more to this picture. Swiss-style machines are designed for small work and have few part-length-to-diameter limitations. Instead of using an indexing turret, as do conventional lathes, the tool indexing mechanism on a Swiss-style machine generally works off a sliding principle, making critical centerline adjustments easier. Swiss-style tooling and workholding is also smaller, which makes everything more “small parts friendly.” A C-axis, subspindle and live tooling is pretty much the norm on a Swiss-style machine, which means you can often drop small parts complete, avoiding secondary operations and increasing accuracy and profitability. In short, Swiss-style machining is the way to go for many micropart turning jobs. “I will do machining down to 3mm on my CNC lathes and screw machines when the part configuration lends itself to those machines,” said Peter McGuire, president of Lovejoy Chaplet Corp., a machine shop in Hoosick Falls, N.Y. “I will then switch to Swiss-style machines for anything smaller than 3mm. The parts become too flexible and are, therefore, much easier to machine on a Swiss-style machine.” Oh, great, you’re thinking. You just quoted a job for 10,000 tiny 303 stainless injector nozzles, and now you have to tell the boss he has to invest in an expensive new machine, even though one job won’t justify the capital outlay for it. Don’t panic. If you’ve got a lathe, you’ve got options for that 10,000-piece injector nozzle order, the one you quoted high because you really didn’t want it anyway. Even if all you have for turning is an old 8"-chuck machine, painted ugly gray-green and limited to a top speed of 3,500 rpm, you still have options. For starters, get rid of that big, clunky 8" 3-jaw chuck. More than likely, the jaw travel is going to be larger than the parts you’re working on, making it impossible to grab a small part. And spinning a chunk of metal at top speed all day long is no fun. The noise coming off that thing is like an F-16 on takeoff. Scary! It’s better to mount a 5C or smaller collet because collets are easier to use for small wo