The story of the first functional AM44 prototype
In 1931, Georg Neumann started manufacturing a high quality disk recording lathe in Germany, introducing the distinctive and instantly recognizable shape of the Neumann lathe bed, which remained in production with only a minor restyling to a more squared-up version, up until 1980, when the VMS80 was introduced with an entirely new design.
The original beds were aluminum castings and every known Neumann lathe ever sold used an aluminum bed. However, during the second world war, material shortages forced many manufacturers to seek alternatives to aluminum, which was becoming scarce.
Neumann experimented with grey cast iron, a material used extensively for the beds of machine tools due to its excellent mechanical properties and vibration damping characteristics. Although it was an excellent choice of material, it was never used on any of their commercial products, probably due to cost and weight considerations.
Neumann stopped manufacturing disk recording equipment in the mid-1980's and was subsequently sold.
A rather investigative type from Solothurn, Switzerland, called Flo Kaufmann, decades later, discovered approximately 30 raw grey cast iron Neumann beds, collecting dust and spiders in a warehouse. He took them home and started the AM44 project, following the original naming convention, with the presumed year of manufacture.
The project aims to bring to life a new disk mastering system, based on these beds built up with newly designed and manufactured parts, which would remain Neumann-compatible, to also be usable as upgrades on original Neumann lathes.
After several years of effort, J. I. Agnew eventually managed to make all necessary arrangements for the acquisition of one of these beds and a bunch of prototype parts, to build up a functional prototype of the AM44, and conduct testing, measurements and further development.
The bed was painted red, having already received the basic machining while still in Switerland. A suitable bench was designed and constructed and the bed was finally ready to be built up into a lathe!
The Neumann lathe bed.
Main bearing unit with subplatter. Notice the strobo? This is for the lathe control electronics.
Adjusting the 16" vacuum platter.
Accelerometer vibration testing.
Slide unit and suspension arm fitted.
Listening for motor noise and rumble.
Vacuum clamp-down platter with vacuum line.
Wiring up the electronics.
Testing motor mounting options and transmission.
Control panel prototype.
Double decoupling motor bracket.
Caruso cutter head and prototype suspension fitted for test cuts.
Adding mass to test suspension time constant.
Adding more mass...
Chip suction tube close-up.
Trying out a new concept for the suspension arm. This precision dovetail assembly came from a Soviet medical/microbiological microscope.
It features precise micrometer dials for adjusting the height, located comfortably far from the suspension.
Trying it all out!
Inspecting the cut with proper optics!
So this is how the prototype came to be.
A lot of testing and development work has been done on this system. Several commercially released records were mastered on it. The AM44 project is very much still in development. Check back to see more progress.
In the meantime, you may find our other lathe projects inspiring. Feel free to get in touch if you would like to purchase an AM44 or other disk recording lathes, or if you need help developing such products.
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