Machinists obviously demand accuracy and repeatability, but according to Mate,these demands also extend to the vice that holds the workpiece. For this reason, Mate workholding functions as a system. A highly accurate and repeatable base needs a highly accurate and repeatable self-centring vice for the system to provide best-in-class operation. Here, Mate reports that its DynoGrip vices shorten set-up time and reduce process variability.

DynoGrip self-centring vices clamp parts to within 15 µm of perfect centre, repeatable to within 10 µm. These results are due in part to Mate manufacturing the lead screw in-house, using tool steel that is properly hardened and coated with titanium carbo-nitride. The screw has a fine 1.5 mm pitch and a trapezoidal thread yielding a strong, steady push.

Perhaps the most important feature is that Mate machines both the right and left sides of the lead screw from the same top dead centre. This process is how the company controls where the lead screw starts and stops. Mate does the same for the internal thread of the pusher to know the top dead centre. Since the company controls every element of the manufacturing process, it eliminates variability and makes it easy to get to the vice to centre accurately and in a repeatable manner.

DynoGrip self-centring vices also have an anti-lift design to counteract natural physicsthat will cause a part to rise up. The pushers and jaws work together to exert a downward force on the workpiece equal to the clamping force. Furthermore, the quick-change jaws feature a serrated tooth geometry which generates a downward force on the workpiece and a deliver superior ‘bite’ into the workpiece.
For further information www.mate.com

Headquartered in Austria, Amann Girrbach manufactures equipment to produce not only dental prostheses such as abutments, crowns, veneers and bridges, but also dentures. In its latest production system, the Ceramill Matik, the company is using a zero-point clamping system from Roemheld group company Stark Spannsysteme. The solution ensures enhanced repeatability when positioning raw material for five-axis milling of the complex profiles that characterise the prostheses. The products are available in the UKand Ireland through Roemheld UK.

Intended for extended periods of unattended production overnight and at weekends, the new machine is an intelligent solution that combines three operations in one: milling at up to 100,000 rpm, cleaning and automatic storage.

Marcel Humml, senior manager operational excellence, says: “The Ceramill Matik incorporates a five-axis machining centre with a 36-workpiece changer, whereas other products on the market have a maximum of 12 workpiece positions and are considerably more expensive.”

He adds: “When testing the Stark zero-point system, we concluded that we would like to have a few modifications. We did not want any visible screws and we preferred exposed sides so that water and dirt could run off better.Due to our compact holder size, we also requested a smaller support surface to save space. Stark undertook all of these modifications in the customised solution they provided to us.The co-operation with Stark during the development phase of Ceramill Matik was unbeatable; the relationship really couldn’t have been better.”

Stark says that its zero-point product is for metal machining on a factory floor and not originally intended for a small production centre producing fine, delicate parts.However, the company was happy to make the necessary adaptations to support automation in the dental sector.
For further information www.roemheld.co.uk