Manual Radius Grinding Machines

Manual Radius Grinding

Machine for PCD/PcBN

The RG5B-XD is the latest in a very successful line of RG machines made by Coborn Engineering in the UK. The machine is unique in terms of strength and rigidity - both are essential for grinding diamond under high grinding pressures.

Many of the machine parameters are controlled via the touch screen. Tools are made in a series of steps e.g. grind facet left, grind facet right, grind radius between facets. Parameters for each step or "block" are saved to the internal PC.

Parameters are: wheel direction, wheel position, wheel speed, wheel stroke length. A tool program is thus made up of a series of such blocks. Programs, once written can be re-called of course or modified as required.

The tool image can be inspected using a projector (as on the machine above). Alternatively, a camera/vision system (VS5-G, see below) can be fitted. The image from the camera then appears on the touch screen.


The Tilting 'Boom' The tool post sits on the pivot table and the pivot table sits on the boom. The boom tilts to give the tool clearance. This is a key feature of the Coborn machine. The machine spindle is fixed and it is the boom which tilts. This means the machine is very compact and there are no large cantilevers which would lead to lack of rigidity.	The Boom locks The boom can be wound to the required clearance by a single handle and is locked in place by keys either side. 'Zero' can be set by a reference pin (seen here to the left of the locking handle). Boom tilt will give cylindrical clearances up to 25 degrees. Conical clearance is obtained by tilting the tool.	In-feed In-feed is by hand, of course. There is an ergonomically placed handle to the left side of the machine.


The tool post The tool post sits on a cross-slide which allows the tool to be positioned left/right and front-back. Vertical adjustment is also possible. The tool nest has a quick release clamp so that the tool and tool nest can be removed quickly and easily - and replaced accurately.	Optics - Option 1 - Projector The machine can be fitted with a projector for tool measurement by inspection. Normally a x50 magnification lens is used. Larger tools may need a smaller magnification lens. Graticules are drawn on semi-transparent paper.	Optics - Option 2 - VS5-G Vision System A camera/vision system is also available in place of a traditional projector. A camera is the best way to view the tool. The image is shown on the touch screen/controller when required. Graticules are generated electronically and the image can be zoomed digitally up to x 400.


Optics - VS5-GM An additional software module ('M') can be added to the basic VS5-G vision system. This allows tools to be measured to +/- 2 microns accuracy at the press of a button on the screen. An area is defined by moving the red lines (shown left); the system then measures the widest part of the tool in the region between the red lines. Setting the lines vertically lets you measure from the highest point of the tool to the pivot centre - the tool radius!.

Contact peter.heath@qs-diamondtechnology.com for further details.