The Secret Society of Lathe Trolls

In a stroke of (bad) luck, my RCA head has come down with the same issue. I'm going to be trying out some ideas me and soulbear talked about for forming a new damper. In the meantime I got my damper out in mostly one piece. Heres a photo Hello! Did you manage to find a replacement for this damper?

I managed to find sorbotane from old stocks. The sheet has lain unpacked since the 90s.

It turned out to be insufficiently hard and viscous. Sorbotan could not suppress all resonances.

It may be necessary to change the setting of the cutting head for the sorbotane damper

If viscoloid is the term for the material and not a general term for plastics, I do not know what is usually understood by the term "viscoloid" in the rest of the world. This is what we call a translucent rubber-like material from yellow to brown colors. Our collectors really appreciate it precisel...

The technology of production of shellac plates turned out to be quite simple. I took my knowledge from both foreign and Soviet books on electroplating and record production. I have access to Arshinov's archive. This man in the 30s from the Soviet record company Gramplasttrest went on business trips ...

This plastic cuts well. In any case, the wear of the cutting stylus would only lead to increased noise on the recording. I conducted a test with a light flare (in our literature it is called the "Meyer Glare"). He recorded a pure tone with frequencies from 30 to 10000 hz. At a frequency of about 900...

A little off topic, but here's a video of playing a homemade shellac record


https://www.youtube.com/watch?v=XIUvlT1-ZzQ

I make records by cutting on plastic. I also mastered the technology of production of stampers and pressing gramophone records from shellac mass. I'll post a video with the results here sometime It is almost impossible to find materials for recording factory production on the territory of the former...

Two sound recordings are presented here. The first recording was made with the original damper. The second recording was made with a homemade damper. A gramophone is not the best device for playback, but even on it you can hear a significant difference in the sound of recordings https://www.youtube....

The armature is centered correctly. All settings correspond to the factory settings The fact is that the native damper was quite rigid and viscous, so the resonant frequency was higher. My homemade dampers are softer, so the resonant frequency has decreased significantly. I have not yet been able to...

Hello! Thanks for the hints. At the moment I use such a simple 12-220 inverter circuit, in it I made a frequency adjustment. The output signal is far from a sine, but the electric motor, due to the large inductance of the windings, works well

Or here is another design, described in the magazine "Radio" in 1941. It uses an asynchronous motor from a fan with a capacity of 50 watts. (But 50 watts is the power consumption, useful power on the motor shaft there is no more than 7 watts). The cone pulley on the motor shaft is used to regulate t...

Understood, thanks for the explanation. An interesting thought. In one of the Soviet tape recorders (the scheme was probably copied from some foreign device) there was a scheme for stabilizing the engine speed. A metal disk with slots and an ordinary magnetic head from a tape recorder were used as a...

I don't quite understand what you mean by the term "electromagnetic brake". Do you mean slowing down an asynchronous motor by applying direct current to the windings as in the circuit I attached to this message?

I think that the motor should be synchronous, not asynchronous. The speed in an asychronous allways decrease as it developes torque. Synchronous motors are rare to find... Hope this helps. 12051180933.jpg Such synchronous electric motors are widespread in our country. But they are not suitable for ...

Thank you so much for your help! Yes, the speed slows down only when cutting. In the Soviet Union in the 30's and 60's the subject of home recording was very popular, so there were several books on making your own recording machine (in our country the state did not produce such machines for home use...