Neumann Lathe Damper Adjustment

How to adjust the damper on the head...

Situated above the cutter head on a Neumann lathe is a mechanical damping system. It is a chamber filled with mineral oil or silicone ‘oil’ (strictly it is a fluid rather than oil as it has no mineral composition), this is attached to the same hinged plate and bearing that the cutter head fits in. There is a perforated diaphragm that sits below the surface of the oil. The diaphragm is attached to the suspension box, and this has an adjustable disc to obscure the perforated holes. This acts to dampen the speed of vertical movement of the whole of the cutter head. When the head is lowered onto the Lacquer, it doesn’t thump down. The amount of damping is controlled by adjusting the resistance to the flow of the silicone through the holes in the diaphragm. By reducing the amount of damping the cutting head is more able to follow thickness variations in the lacquer coating. Fine adjustments of about 1/8 of a turn are all that are required, and utilise the Damping Test function (on a VMS80, for other models swiftly adjust manually) to alternate between 150µ and 40µ / 50µ depth and inspect the starts and ends of the depth transitions: adjust for minimum ‘bounce’ when depth changes, too much damping is evident in slower transitions, the ideal setting is the minimum damping required to achieve smooth transitions - it is better to have slightly less damping than too much, in order to follow better the imperfections the lacquers.

The images below show the location of the damping system and the dash pot.