Scratching the sound on the cheap

[harry dalek]

I am working on a tiny Lathe made from a old dvd motor just using that for the turntable ...an old dvd laser tracker for the lathe movement and 2 video camera geared motors for the tracking and turntable slow movement .
Bit reusing some junk laying about
Working on the cutter the problem iearly stages very early !..and the problem i see is the cut or scratch in this case has to match track other wise play back stylus will slip or sink ..in this case it does both nice and cheap fix !

I needed to test the idea out so put together a very crappy quick knock up pulled to bits cartridge with the laptop speaker and a pen cone sewing needle to transfer the vibrations to the old stylus .... a few sec's of recording shows some promise and i was just hand tracking and holding the thing together...so in the short video is a few secs i managed to get not great but does show it will record , i will fix it to my lathe soon when i glue this thing together.

I am not wanting to make the best lathe possible but a mono mechanical sound recorder which i hope in further experiments will have enough bandwidth for my needs which in time might surprise you as it will be nothing ever tried on this forum .

[mrd]

Nice work! Really like the idea of re-using the scrap electronics

[piaptk]

Thats nuts! Nice work!

[harry dalek]

Thanks MRD and piaptk few weeks ago i never knew what a record lathe was but i have a need for my Main hobby narrow band Television I want to record Video like john logie Baird on a record ,its not that easy as any deviation in speed will cause problems in syncing i may have to reconstruct the sync pulse and reinsert it on the out put video .
Here still very early stages if all go's well i will be lucky to get a simple poor image but it is fun trying making every thing from junk ,bit of tweaking correct some mistakes like speed angle of cut such might get there .

[opcode66]

That's a lot of motor noise.

[harry dalek]

That's a lot of motor noise.

I think its mostly the angle of cut being wrong i forgot and went dead vertical but yep another problem to fix for sure or hope to !
Think i need some damping also under the cd (felt) it worked on the case floor to stop it acting as a speaker !
Any motor vibrations should be cut out this way ,i will work onit again later in the week .

[symatic]

that's awesome

[mrd]

Thanks MRD and piaptk few weeks ago i never knew what a record lathe was but i have a need for my Main hobby narrow band Television I want to record Video...

Nice! Are you aware of this? - https://obsoletemedia.org/vinylvideo/

[harry dalek]

Nice! Are you aware of this? - https://obsoletemedia.org/vinylvideo/

Yes it's been around a few years now shows how good it can be ...doing well recording it on a 45 rpm !
Baird recorded on a 78 rpm 30 lines no sync below a link to the remaining recordings only a few exist that first page link is a private recording off air from the 30 line Baird BBC tv service on a cheap lathe of the time ! amazing
https://www.tvdawn.com/earliest-tv/the-silvatone-recording-1933/

[harry dalek]

Version 2 and 3 of the lathe below ..i have an embossing stylus coming but the below photos and videos are where i am up to at the moment .
The stepper motor has great torque and with a speaker cone great sound if any thing i expect higher volume record . Interesting idea in the youtube video !
https://www.youtube.com/watch?v=C9vcqTHhu_Y

[soeffingodly]

Very cool! Well done.

[harry dalek]

Very cool! Well done.

Thanks ! it is harder making the turntable as well and a problem to keep it at the correct speed RPM with just voltage control .
So my next step is to sync the strobe encoder disc under the turntable to a crystal clock running at 50 hz i could do 60 as the strobe disc has both printed on it just have to change the crystal circuit .
Any case what i use is for feed back to a motor control circuit using a PLL or a bistable switch i have used both for motor control in the past but never so slow !.
Any sort of video signal the turntable has to be running correct to the Hz,i don't know if its possible at these slow record speeds but john logie baird did it at 78rpm in the early 30's with just gearing syncing ....if all gos well back to Slow scan tv 120 line test apart from correct record speed it only needs under 3khz bandwidth.
Any way heaps of work still to do but this is on my mind now.

[harry dalek]

Been a while since posting but i did mage to emboss record SSTV video on a CD ,the big problem as you see is keeping speed correct thus the line wobble ...the syncing is swinging with motor speed .
The platter DC motor is the problem so i am swapping the motor so up sizing the project ,i want to first get correct syncing and 2 up the bandwidth of the recording so i can move onto NBTV.next post i will show what i am up to
Recording and play back here was from same device ..i used a tiny stepper motor for the lathe head it has a bandwidth to 8 khz fine for sstv not NBTV need at least 10 khz here .

DSCN6404.jpg

[harry dalek]

First Tests on the Mk2 home made lathe ,some 8 second Slow Scan television again used in tests .
My hope was the embossing would not effect the speed on record but it does darn so play back is to fast i used a magnet as an eddy current brake to get the video back to correct speed 78 rpm

[Fela Borbone]

Amazing! Love it..

[harry dalek]

Amazing! Love it..

Thanks Fela

I would love to get to the point as this fella did more a optical record but than mechanical recording .
So there's not much new under the sun ; )
in 2006 Jeremy Jago did some mechanical NBTV recordings on record looks to be 78 rpm ,i will be increasing motor speed and more bandwidth on the recording head...i expect many more months of work here /

[harry dalek]

Well i have managed to record and play back NBTV on a record mechanically first results not perfect but getting there !
https://www.youtube.com/watch?v=wAua8z4Onq8&t=19s

https://www.youtube.com/watch?v=hiPvadVCw7o&t=85s

[harry dalek]

Latest recording 45 RPM pulse width modulation NBTV video recording ,i need to work on the platter speed problem the embossing causes a speed to slow a touch so the recording is faster on play back i use a magnet for eddy current braking to help get it in sync ...much harder at 45 RpM ! a mistake recording !
[YouTube2]https://www.youtube.com/watch?v=hUpUE84MzpI&t=28s[/YouTube2]