UK diamond toolmaker, Cranden Diamond Products has recently invested in a new Wasino GLS-5T Optical Profile Grinder. The acquisition of this machine is a major part of the company's expansion program to maintain its position as a leading manufacturer of high precision profile CBN and diamond grinding wheels.

Cranden Diamond Products was formed by Andrew Cranshaw and Eric Dennis in 1985, to specialise in the manufacture of electroplated and resin bond diamond and CBN tooling. From its purpose built factory in Kent, the company produces on average 500 profile grinding wheels per month, electroplated with diamond and CBN. Tools are manufactured to within +/- 3' on angles and tolerances of +/- 3 microns over the abrasive coating. Cranden employs 45 qualified engineers and laboratory staff and exports 60 % of the products it makes to a worldwide customer base.


The reason for the purchase of this machine was that Cranden had noticed a technological shift from skills-based production of profile wheels to CNC accountability during quality control of its products. CNC machinery often needs to be 'told' where a specific form on a wheel actually is, so a machine was needed which had the capability to grind profile forms to within sub-micron tolerances, and to be able to check and prove the integrity of each ground part on the very machine that produced the form. It was Cranden's opinion that the best machine on the market for such work was the Wasino GLS-5T. The Wasino complements Cranden's machinery range of Mazak CNCs and Agie wire eroders.
With the GLS-5T OPG, accuracy levels are exceptionally high with the machine's measuring system having a resolution of 50 nanometres (0.05 of a micron) and so achieving high positional accuracy of 0.1µm with surface finishes < 0.1 µm.

The machine has 4 axes, with option of 5, the screen is 540 x 420 mm with 20:1 and 50:1 magnification and an option of a further 2.2 x screen loupe. The table is 400 x 250 mm, grinding area is 300 x 150 x 150 mm, with a wheelhead/spindle stroke of 0 - 155 mm and up to 400 strokes per min possible. Spindle speeds up to 6,000 and 20,000 rpm are standard. The wheelhead swivels front to back, side to side and rotary to cover clearance angles and profile forms.
Wasino's unique feature of programming is using the 'teach-playback' function: a drawing/plot of the profile is placed on the screen and, using the handwheels, the operator moves the tip of the wheel to the profile touching in several places (3 for a radius etc) and presses a button to register each position. This operation is finished in seconds and the machine can then grind the profile either semi-auto or automatically. The profile can then be checked against the plot and adjusted for any slight wheel wear by further teaching with the worn wheel and so producing perfect parts from an in-perfect wheel. Parts are therefore known to be correct before removing from the machine.