What does a vinyl record groove look like?


I have been scouring the internet in an effort to better understand how vinyl is cut and what the groove actually looks like, and therefore tracks like. This is what I think I have learned. A record cutter is a 90 degree V-shaped chisel that undulates back and forth and up and down and in so doing cuts vertical tracks into the sides of the groove it cuts. Bass notes are large undulations (relatively speaking) with midrange and treble undulations riding on top of them and along with them. According to Neil, who might chime in here, the cutter is tilted back 1 degree like a chisel might be, in order to peel up the vinyl that it removes as it cuts. Am I right when I say the cuts in the 90 degree sides of the groove are then 1 degree of vertical (as you look at a groove from the side)? What confuses me is I keep reading articles that talk about 22 degree, or 24 degree, or something like that, cutting angles. What is this all about? My whole purpose here is to completely understand how a groove really looks so I can better understand how a stylus can best track that groove. Not to mention it is flat out amazing to me that all that information can be cut into the groove of a chunk of vinyl in the first place.
240zracer
Most of the contributors to this thread will find this info elementary but the sites are good resources and the vinyl groove photos are unique

Micrographia

Westrex Cutting Head & Scully Lathe
Dougdeacon, I thought that the lateral movement of the stylus produced only the mono signal, and the vertical movement gave the signal the stereo balancing. Am I wrong about this?

I thought that the lateral movement of the stylus produced only the mono signal, and the vertical movement gave the signal the stereo balancing. Am I wrong about this?

The first few pages of the Michael Fremer Setup DVD includes a .PDF file that gives an informative accounting of how it works with some nice diagrams.

Rgds,
Tim
Fatparrot,
You're right, but vertical stylus movements are not a result of the groove itself moving up and down. It doesn't. Vertical stylus motions result when a different undulation is cut on one groove wall vs. the other. This differential between the resultant L wall and R wall vertical motion creates L-only or R-only signals.

From the information sheet included with my HFN&RR test record:
On a stereo disc the two groove walls carry related but nevertheless independent signals, each wall undulating at 45 degrees to the record surface. ...

With modulations on one groove wall only... a stylus perched firmly in the groove must move both laterally and vertically.

In stereo recording and reproduction those sounds emanating from the center of the picture are represented by exactly equal signals in the left and right channels, and in accordance with an agreed convention such signals operate the disc cutter so that as one wall goes up the other comes down, resulting in purely lateral groove movement. This of course, is the same as on mono discs, which can be regarded from this point of view as stereo recordings of central sound sources only.

Doug