The Secret Society of Lathe Trolls

Mark, I believe that you are correct. I don't have personal experience with cutters that do not employ electrical feedback, so I'm probably not the best person to advise you here. But my understanding of your cutter is that it is performing as constant velocity responding above its resonance of abou...

Looks like a Westrex mono cutter to me. Maybe a 2A or 2B. Definitely a professional cutter.

Nice looking piece, markrob. I'm not very experienced with machine tools, so I may be asking some dumb questions, but here goes: What material did you use - mild steel or tool steel? What kind of cutting tool did you use - steel or carbide? How did you cut the .0625" slot in the end of the piece? Do...

No, disc records are not designed to shrink after they are molded. I used to cut test records that required some very accurate diameters be recorded on them, so I conducted some experiments to determine what shrinkage may be taking place in vinyl record molding. The results showed that very little t...

Diamond cutting styli are not indestructible. I used diamonds for cutting CD-4 masters, so I have some experience with them. They wear about 10 times longer than sapphire or ruby when used to cut lacquers. But the edges are very delicate as on any stylus. They can easily get chipped which will resul...

For anyone interested in the early days of acoustic phonographs, the following books are very helpful: "Edison Cylinder Phonograph Companion" by George L. Frow "The Edison Disc Phonographs" by George L. Frow "The Compleat Talking Machine" (note the spelling) by Eric L. Reiss "Look for the Dog" (Vict...

Looks like a Neumann AM-32b lathe. Not a Neumann cutter head. Press is a Toolex-Alpha 7 inch.

Glad to help any way I can, Thomas. Fire away.

The Talking Machine Forum has regrouped under an internet domain owned by one of the members. This way, there aren't going to be any third party hosts to pull the board down when a catfight ensues. The OTV Board lost most of its members to the Talking Machine Forum and the TMF is now much more popul...

Flowing, one of the things that people experienced with digital recording don't realize is that doing things in analog is extremely difficult to speed up beyond real-time. Digital recording either by magnetic or optical means can pretty easily be done at many times faster than the real-time playback...

I'm not sure what happened today (the OTV board is apparently down). But the OTV board has been rapidly losing members and views due to internal political fighting between the administrator and some of the members. Most of the members have gone over to another board called The Talking Machine Forum:...

You want axial poles for this application. The coil of wire will form axial poles when current is applied. This needs to attract/repel the axial pole field provided by the permanant magnet.

The JVC AHD and VHD discs were compression molded out of a PVC-based compound, if I remember correctly. The process was very similar to that used by RCA in their SelectaVision CED videodisc. Some of our RCA CED manufacturing engineers were asked to consult at JVC during their attempts to get a VHD p...

Some interesting videos here. The last one featuring the 7 inch automatic press is showing a Toolex-Alpha press making vinyl records. We sampled one Alpha 7 inch press and had it running for several months along with our 49 Alpha 12 inch presses, but we couldn't justify keeping it. We just weren't d...

Steve, you might want to check out the following forum/discussion board: http://sonoraman.proboards107.com/index.cgi? The site, the Old Time Victrola Music Message Board (OTVMMB), deals primarily with acoustic phonos which our readers might also find interesting, but it has been stable for a number ...

I'm not an expert in injection molding, but I believe that PVC is too viscous to be injection molded, particularly into the shape of vinyl records. Even at the temperatures used in compression molding, the vinyl is dangerously close to burning up and/or otherwise chemically decomposing, and it is st...

Well, I feel pretty qualified to comment on this topic of record wear. One of my research projects while I was RCA Records manufacturing in Indianapolis was to evaluate new record compound formulations for record wear. We performed tests under several wear conditions that represented typical custome...

Bob, yes, the reason styrene was used in the making of 45s in the US was COST. Process cost, actually. The styrene compound was available mostly from one supplier, Richardson Plastics. It came in pelletized form and was easily fed into the extruder hoppers. Richardson had spend a lot of time develop...

Just curious, CC, how large a pressing plant did you work in during the "good times"? You are right that the Toolex Alpha presses are more common in europe, but we had 7 lines of 7 Toolex Alpha presses each (49 12 inch presses total) running at the RCA Records plant in Indianapolis up to our closing...

The "cutting angle" of 15 degrees that you are probably referring to is defined as the vertical angle of modulation motion. It has nothing to do with the physical dimensions or angles of the stylus. The 15 degree angle which has been standardized for STEREO recording is such that the direction of ve...