Working principle:
The VD 3 machines the valve seat in a lathe-type facing operation. A pilot is locked in the valve guide to align the VD 3 in centerline with the valve guide. The VD 3 is placed on top of the pilot. With the single point carbide cutter positioned in front of the inside edge of the valve seat, the proper depth of cut is set.
The depth of cut is set by a micrometer mechanism to maintain positive control over the stock to be removed from the valve seat.

When the VD 3 is then rotated on the pilot, the cutter travels in a circle around the valve seat with continuous outward transverse feed motion under the proper seat angle. As a result, the seat is refaced to concentricity with the valve guide under the correct seat angle

Features:
The tool head includes two toolslides guided in dovetailed slideways inclined under different valve seat angles. The single point carbide cutter can be attached to either toolslide. A feed gear mechanism in the tool head ensures continuous tool slide traverse, when the VD 3 is rotated around the pilot. Cutters with indexable carbide inserts are available in addition to standard carbide tipped cutters.
The standard carbide tipped cutters can be resharpened on a normal tool sharpener.
Solid and adjustable pilots are available to align the VD 3 in centerline with the valve guide.

Application:
The VD 3 is a low cost hand tool for refacing valve seats. The VD 3 refaces even hard seats and especially tough seat materials like Nimonic which, when machined by grinding, tend to load the grinding wheel rather fast.
Roundness, concentricity and surface finish of the refaced valve seat are within manufacturers’ specifications.

Specifications: Capacity: Valve seat diam. 60 - 200 mm Valve seat angle 45° & 30° or 45° & 35° or 30° & 20° Tool Head: Drive manual Feed rate: . Transverse feed 0,05 mm/rev Dimensions & Weight: Width 300 mm Depth 250 mm Height 350 mm Net weight approx.8 kg