Precision International Corp.

United States

Coborns Planetary Scaif benches are generally used to polish facets on single crystal diamond tools. They may also be used in gem diamond polishing. The bench combines the high speed rotation of a scaif plate with a relatively slow, smooth, horizontal planetary motion. The planetary motion speed is variable between 0-50 cyclesminute. This motion gives a number of advantages over a standard scaif: The plate does not become tracked as polishing takes place over an annular band. The scaif surface remains smooth and flat.The motion results in a constantly changing angle of attack: this gives a self-zooting action producing line free facets without manual work.In many situations the tang can be set on the machine and the diamond or tool left to polishKnarted stones become easier to polish as the angle of attack constantly changes.All planetary benches are fitted with a 2.2kW, adjustable height spindle. The working height of the plate surface can thus be re-established after the plate has been remachined. PS benches can be supplied with either a fixed (type A) or adjustable (type B) planetary stroke. An inverter drive can be fitted as an optional extra.

The precision Rotary Grinding attachment converts Surface Grinding machines into a rotary grinding function, offering users greater operating flexibility and improved machining economies. The attachment can be used both on standard and CNC Surface Grinders, the unit fits easily into machines which have enclosed guarding arrangements and performs well under flood coolant conditions. The rugged design of the attachment provides a high level of accuracy in respect of flatness and surface finish. The attachment conforms to European directive 9837EC, supported by EC directive 7323EEC and EC directive 89336EEC respectively for the Electronic Controller and Electric Motors.

Coborn scaif (or skive) spindles are precision instruments designed for years of continuous use for diamond polishing. These spindles have an unmatched reputation in the gem and industrial diamond industry. Spindles are direct drive motors for the scaif plate and normally sold to be fitted to the customer's own benches. The options are: Horsepower (1.5hp or 3hp 1.1kW or 2.2kW)Fixed or variable heightStandard or self pressurized, air-flow typeIf only one diamond is being polished, 1.5hp will be adequate; 3hp is better for multiple users or fixtures. The Expanding Nose is a very important feature, which ensures the scaif plate is centralised onto the spindle axis for smoother running and makes the changing of scaif plates much easier. As plates wear, they must be re-machined occasionally. If fixtures are carefully set, then it is useful to be able to raise or lower the height of the plate surface to maintain its working level. A variable spindle is available. It is recommended dust is removed constantly during use to protect operators. An air-flow type spindle is available.This uses the natural centrifugal action of the high speed rotation of the plate to draw air and dust into the bowl beneath and then to a filter or external exhaust. We recommend you use a PB2 Portable Balancer to dynamically balance the scaif plate in-situ.

Coborn scaif (or skive) spindles are precision instruments designed for years of continuous use for diamond polishing. These spindles have an unmatched reputation in the gem and industrial diamond industry. Spindles are direct drive motors for the scaif plate and normally sold to be fitted to the customer's own benches. The options are: Horsepower (1.5hp or 3hp 1.1kW or 2.2kW) Fixed or variable height Standard or self pressurized, air-flow type If only one diamond is being polished, 1.5hp will be adequate; 3hp is better for multiple users or fixtures. The Expanding Nose is a very important feature, which ensures the scaif plate is centralised onto the spindle axis for smoother running and makes the changing of scaif plates much easier. As plates wear, they must be re-machined occasionally. If fixtures are carefully set, then it is useful to be able to raise or lower the height of the plate surface to maintain its working level. A variable spindle is available. It is recommended dust is removed constantly during use to protect operators. An air-flow type spindle is available.This uses the natural centrifugal action of the high speed rotation of the plate to draw air and dust into the bowl beneath and then to a filter or external exhaust.

PCD is hard - very hard. If you want to grind PCD tools then you need high-quality vitrified bond wheels from Trochilics Ltd - the sister company of Coborn Engineering. Coborn has over 60 years experience in machines for cutting, polishing and grinding diamond, PCD, CVD and PcBN ultra-hard materials so they know what they are talking about. If a diamond wheel is to grind PCD it must be kept open by frequent dressing. This exposes new sharp diamond and keeps the wheel cutting freely. A dull wheel can soon start to vibrate or chatter especially if the machine is not rigid. Wheel, machine and PCD all interact. Soft wheels will grind easily but then the life will be low. A hard wheel may not suit your machine. A few experiments are needed. Trochilics Ltd offers 5 vitrified bond formulations with varying degrees of hardness and diamond concentration. The OLIVE bond is a universal, general-purpose bond recommended for manual machines: the KILO bond is designed to give very consistent results on CNC machines. All wheels are dynamically balanced. The standard wheels are held ex-stock in the UK, ready for immediate shipment.

The LM is a linear motion axis with a position accuracy of 1m. It mounts directly onto the toolpost of the RG9. It allows: multiple grinding positions movement of the tool axis by up to 75mm This combination allows the manufacture of tools such as:helical tools stepped end mills stepped reamers

The DIAFORM CNC system is simple, fast and accurate both to program and set-up. DIAFORM CNC has full 3 axis dressing capability. When linked to machine control can provide up to six axis capability using high accuracy diamond tooling, both single and rotary. No matter what the machine, the DIAFORM can provide all the benefits of specialist CNC form grinding. Features 0.5 micron resolution sets the diamond tool presentation to the profileFull 3 axis single and rotary dressing capabilityHigh surface finish with constant material integrityFits surface, cylindrical, centerless & special purpose grinders and grinding wheel forming machines

Templates for either 10:1 or 5:1 reduction dressers can be used repeatedly for tool room or production applications. Conventional machinery can be used to produce the template. Alternatively CNC milling and wire cut EDM machines can generate templates quickly and with the use of outputs from CAD machines. Permanent profile reference for unlimited redressing with guaranteed micron accuracy

The Optidress E Diamond Wheel Profiling System, available for use with the Optidress E Form Wheel Dresser, provides a highly cost-effective alternative to creep feed or crush grinding, as well as off-line form wheel dressing. Crush grinders require a separate diamond roll for each shape, while the Optidress Wheel Profiling System lets you redress the same grinding wheel multiple times. Features Controlled dresser arm movements (0.0001 in all directions)Dress form wheels up to 12 in diameterWorks quickly and accuratelyForm or redress grinding wheels without removing them from the machine spindleFree video availablePrecision International also offers specially-designed resin bonded diamond wheels for use with this system (not a requirement)

This versatile Rotary Grinding Table with built-in sine table and variable speed motor quickly converts a surface grinder to rotary circular work. Highly accurate setups are possible for precision prototype or production toolroom work.

PCD is hard - very hard. If you want to grind PCD tools then you need high-quality vitrified bond wheels from Trochilics Ltd - the sister company of Coborn Engineering. Coborn has over 60 years experience in machines for cutting, polishing and grinding diamond, PCD, CVD and PcBN ultra-hard materials so they know what they are talking about. If a diamond wheel is to grind PCD it must be kept open by frequent dressing. This exposes new sharp diamond and keeps the wheel cutting freely. A dull wheel can soon start to vibrate or chatter especially if the machine is not rigid. Wheel, machine and PCD all interact. Soft wheels will grind easily but then the life will be low. A hard wheel may not suit your machine. A few experiments are needed. Trochilics Ltd offers 5 vitrified bond formulations with varying degrees of hardness and diamond concentration. The OLIVE bond is a universal, general-purpose bond recommended for manual machines: the KILO bond is designed to give very consistent results on CNC machines. All wheels are dynamically balanced. The standard wheels are held ex-stock in the UK, ready for immediate shipment.