The Secret Society of Lathe Trolls

Yes, that's correct; I have two of the K series units and they are not capable of cutting spiral grooves. Only the larger overhead machines could do that. The smaller machines with an overhead (12 and E series) couldn't cut spirals either; just head up and down only.

If the unit originally had a crystal head, the drive is coming off the plates of the output tubes (~180 VRMS). This would fry a magnetic head. A magnetic head was made for the Recordio series, the Astatic M-41, which show up on ebay occasionally. However, to use this head with the original electroni...

Sorry this took so long; here are the two pages of the tech literature that came with the Grampian head:

This does a good job of demystifying the 78 manufacturing process:

https://www.youtube.com/watch?v=2zL53iEHf_0

I have the manual for this head; will scan it and post when I get home from work today.

If I remember right, the Recordette series had a built-in microphone; little plastic thing that stores in the lid of the unit and a cloth bound cord goes down through the turntable deck into the machine. This is also a crystal element mic, which what you're describing indicates that it needs to be r...

The link posted doesn't work. Is there another web address to use?

The correct spelling is Charles Cros (one s). He did design the Paleophone, but never made a working model. Edison had a similar idea inspired by Bell's telephone - he basically turned Bell's "gallows" transmitter on its side and added a moving medium (foil) to actually put down sound so it could be...

This article covers a lot about mechanical recording:

http://journal.sciencemuseum.ac.uk/browse/issue-03/the-art-and-science-of-acoustic-recording/

https://www.tcm.com/video/206271/unsuspected-the-1947-movie-clip-i-rather-enjoy-playing-god

Hmmmm... the room must have been cooled with liquid nitrogen if a metal lacquer shattered when smacked over the guy's knee.

Yes, very well planned, meticulous and precision work!! I took metal shop in high school and was very interested in machining, but didn't pursue it. I do understand what painstaking work doing something like this would require.

The moving platter is nothing new; lathes built for acoustic recording on wax (Lindstrom, Scully, etc.) had the platter moving under the recorder. This was because the horn or horns of varying sizes and shapes used for recording, couldn't move along with an overhead or sled assembly as with modern l...

A big problem with the old hobby cutters is that the 80's idler wheel's rubber is usually at the end of its lifespan and hard or in need of conditioning or replacement. Replacement is generally a custom machine shop copy. This can be done for about 100 bucks or so if needed. Try Terry's rubber roll...

Try Aaron at http://www.blanqrecords.com I have used his discs and they're very quiet compared to others. You have to use a diamond cutting point, which you can get from myshank, which IMHO are the best diamond styluses made. I have also successfully used a NOS stellite point on Aaron's discs with g...

I'm not sure but maybe a #4-40 might work?

Yes, I highly recommend MyShank; just got a diamond for plastic for my Westrex head and it was excellent quality.

Yes, I think an old large floppy disc would work as well; same concept. The other machine's discs I think were thinner. The Mail-A-Voice was intended for dictation and business communication. The discs would fold and fit into a #10 envelope for mailing. At the other end you unfolded the disc, got th...

One of these discs would work as well; for the GE Play Talk toy:

https://www.youtube.com/watch?v=hDo3awqwCvc

If you can find a disc for a Brush 'Mail-A-Voice' machine it would work; the Timex is the same concept. Drive disc in the center with a tracker and the magnetic head is at the end of the "tonearm".

Like this:

https://www.ebay.com/itm/265220657358?hash=item3dc06210ce:g:i7IAAOSwAW9gy-7L

Also done. Thanks Steve!