Cutting audio onto a bottle - special project

[Gyro]

I'm undertaking a special project that is linked to an album release that is sponsored by a beer company that sponsors emerging artists.

Basically the brief is to record a music track onto a bottle and be able to play it back at various venues associated with the album release using a dedicated playback unit we would build .
The creatives from the advertising agency have hired my company Gyro Constructivists to build the device.

I have spent much time so far investigating the feasibility of the idea over the past week.

Here is the process I'm looking at to date, but I'm certain once I post this there will be a flurry of alternative ideas:
Being aware the we can't cut into a glass bottle we intend machining one from solid acrylic, we can do test cuts onto an acrylic cylinder, and also explore the possibility of coating a bottle with a thermo sensitive layer, perhaps epoxy resin, or a methyl-cellulose paint coating.
Cutting lathe will consist of a powered gantry that has speed control for the horizontal axis.
A cutting head (ideally heated) mounted to the gantry will traverse the horizontally mounted bottle. The bottle to would be mounted on a computer controlled lathe mandril that will allow precise control of rotational speed for optimum recording quality.
Cutting head fed with inverse-RIAA EQ for playback with commercially available linear tracking mechanism and amplifier with phono input.
I suspect a mono recording as it allows for higher levels with less chance of needle hopping.

Options for cutting device for the bottle:
1. Source a T560 cutting lathe from Vinyl recordings Germany
2. Build our own lathe using commercially available cutting head
3. Build cutting head from scratch, not preferred!
4. Alternative option for cutting using hard drive actuator arm fed with an audio signal fed with the inverse-RIAA EQ to limit movement of the arm by excessive bass input, and mount the tip much closer to the axis.
Link httpd://www.youtube.com/watch?v=uM63nUaGgao
5. Engage services of audio engineer for the cutting process enabling correct audio mix for our usage

Playback of device for the bottle:
Comprising sourcing of a linear tracking tone arm mounted above the cylinder using a lathe mandril similar to unit in the cutting process.

Engage services of audio engineer for the cutting process enabling correct audio mix for our purpose, utilizing the official inverse-RIAA EQ for phono recording and playback.

Any help would be appreciated, especially regarding the use of a hard drive actuator instead of a cutting head assembly.

We build models and special effects for the film industry and have the engineering expertise but lack any experience in this particulat field.
Website: https://www.gyro.co.nz
Thanks in advance Andrew Turney

[dubcutter89]

Hi!
Cutting into beer-cans has been done before,
contact flo kaufmann: http://www.floka.com

don't know if it is possible for glas...

cheers

[concretecowboy71]

I saw somewhere that audio was found in grooves on ancient clay pots.

Might have been a hoax, but the idea seems somewhat plausible with modern technology.

Maybe clay bottles?

[opcode66]

I believe that was an episode of X Files....

[concretecowboy71]

Yes, they did use that on the X-files but there were some actual cases where people claimed this is possible.

Love the X files!

[THEVICTROLAGUY]

GREETINGS,
the process is actually quite easy i think. the Edison cylinder phonograph is already set up to do the recording, all you need is a sleeve to slip over the bottle that has been recorded on an Edison cylinder phonograph. there are several ways to do this, the easiest would be to simply record a cylinder then slide it on to the bottle. i have a recorder that will produce paper thin cylinder recordings. you could also produce a " napkin ring " cylinder, essentially a cylinder recording about two inches wide that will hold one minute of audio, i have made several of them.

to actually record on the bottle is not possible unless you use the method of coating the bottle with wax, cut the modulated grooves, then using acid " develop " the grooves, leaving the recoding on the glass. you could try the new 3d printer method of recording and play the label. lots of possibilities, but since the Edison phonograph is already producing cylinders, it seems like that is the logical place to begin, rather than building some elaborate computer controlled device that is going to be used for a simple demonstration. let me know if i can be of assistance with this.

Benjamin

https://www.youtube.com/embed/dvk6UtWcl_Y?feature=player_detailpage

https://www.youtube.com/embed/WwWtY6izI7Y?feature=player_detailpage

[THEVICTROLAGUY]

here is a follow up demo recording on a cylinder. this was recorded on my iphone as an m4a audio file, a voice memo in fact. transferred to a cylinder using my recording process and is playing through a guitar amplifier. just a thought, but the process seems perfect for your needs. size constraints of the cylinder are a consideration, but i have no doubt the process can be modified to produce any size cylinder you wish. a sleeve would be the easiest way to proceed, slipped on to the bottle and you have an instant playable record.

Benjamin

THEVICTROLAGUY@GMAIL.COM

https://www.youtube.com/embed/QthGIBRplms?feature=player_detailpage

[piaptk]

He said in the original post he is making the bottle out of acrylic. Ive cut acrylic with standard ruby styli and it cuts fine... Before i figured out how to emboss/impress on poly, i used acrylic a lot.

I think making an acrylic wrap to slide over the bottle and then cutting it on a cyclinder recorder is the way to go.

[piaptk]

Also, if you are in NZ, contact Peter King... he is an OLD SCHOOL lathe cutter, and as far as I know, one of the original experimenters with alternative materials, setups, and homebrew equipment. He is also one of the coolest dudes I know. http://www.peterkinglathecutrecords.co.nz/

[Gyro]

Thanks for all the feedback and tips you have all contributed.

However I do need to get as high a fidelity as possible over a 3-4 min duration.

The brief is to cut into a bottle, so a sleeve would be a last resort of the other alternatives aren't up to scratch. So I'm experimenting with a various coatings over the next week.

I've tested a hard drive actuator be resting a stylus on the tip and feeding a signal to the actuator using the RIAA EQ with surprisingly good results for a first attempt, some arm damping is required, possibly a paddle in a silicone fluid trough or a solid damping buffer or travel limited and tweak the EQ of the output signal, although this is only theory.

I like the idea of cutting a wax bottle but suspect the etching process will leave a rough surface without a "V" groove.

I have had a few conversations with Peter King, who is very willing to help although he is pretty hard to contact as he doesn't use email or have internet access I suspect.

Link for the actuator tonearm proof of concept.
https://www.dropbox.com/s/cyeox7k46ywf0zo/Actuator_Playback.mp4
https://www.dropbox.com/s/g0aot6z857x5q80/Actuator_Playback.jpg

Does anyone know if it's possible to heat a metal stylus which is easier to source than a sapphire tip.
I was chatting with Robert Stebbings today who used to cut masters back in the day, he suggested 5-6 turns of ni-chome wire fed with 2volts AC.

Look forward to your input.

I'll post work in progress over the coming weeks.

Andrew

[markrob]

Hi,

Cool project.

When I was making my homebrew steel stylii using HSS drill blanks, I had no problem heating them using a few turns .005" diameter nichrome. I bonded the heater coils to the shank using Duco cement which is nitrocellulose based. After winding, I would cook the Duco by running enough current throught the wire to make the glue smoke a bit. It seemed to create an insulation barrier between the wire coils and the steel shank. You'll will probably need a bit more voltage than 2 volts. You really want to control the heat by monitoring the current (typically about .5 amps). I use a HP bench supply in constant current mode, but a simple variable DC or AC supply with a series resistor works fine. Something on the order of 12 volts should do it. You won't have all of that voltage drop across the heater, most will be across the limiting resistor.

However, If if you plan to make multiple cuts, I'd go with a standard saphire stylus from Transco. I'd use the Neumann tapered style as it is short. Steel just doesn't have a long cutting life.

Mark

[Techie]

Does the bottle project have to be a groove? You originally said you needed to record onto a bottle. Is a magnetic coating an option? My mind wonders sometimes....

[Angus McCarthy]

2¢:

I'm not certain why you'd go through the trouble of re-inventing the wheel on this project. It would be fairly straightforward to build a transport similar to that of an Edison machine (or, actually retrofit one - old-school factor!), and simply use an existing Mono head to cut a lateral groove (if that is your intended format). The drawback I see with trying to cut laterally is that you will have to sacrifice potential recording time to gain volume - and remember that there is -maybe- 6 inches of circumference to your average beer bottle (being generous). That means to maintain fidelity, the bottle will have to spin about three or four times as fast as a 7-inch single to achieve the same kind of linear speed. That means three times as much horizontal space.

If you need to squeeze as much as 4 whole minutes onto this thing, your best option may actually be a vertically-modulated groove, since there is little to no land wasted between each rotation. In this case, you would need to play back the bottle on a machine that drives the playback head across the bottle at the same rate as the recorder - just like an Edison machine. You could track down a working, stock, vertically-cutting head, but you would be a lucky man indeed. Your best bet there would be to construct a purpose-built head.

[Gyro]

Hi all,
Had a long chat with Peter King last night regarding cutting tips and heating thereof, so that's todays task, once I collect the ground tungsten carbide tips which are reground cutting blades used in the vinyl signage cutting machines.
I've been warned against hill and valley cuts as the stylus is likely to jump from the groove with the bass present in the audio. I've found a great linear tracking arm the Pioneer PL- L1000, also a Rabco SL-8E linear tracking Tone Arm, along with 4 other cheaper linear arm turntables for testing.
http://lhchangaudio.blogspot.co.nz/2011/03/pioneer-pl-l1000.html

Any tips on the arm is welcome.

Cheers Andrew

[diamone]

I'm undertaking a special project that is to...record a music track onto a bottle. We intend machining one from solid acrylic.

Don't re-invent the bottle. All kinds of guys these days are doing modern electric cylinder masterings and mouldings. Places will sell you freshly mastered and moulded onto PVC cylinders of Madonna or Maroon 5 or whoever you want - and they already have the modern cylindrical mastering and moulding perfected. So all you'd have to do is change the mold from a true cylinder to that of a bottle. Or, do what one guy did and mould the cylinder out of clear PVC and then mould the top and bottom of the bottle as if they were end-caps to the cylinder and attach them thereto.

[Steve E.]

Diamone has a good point. Peter Dilg in Baldwin, NY is one guy who does cylinder moulding.

[Gyro]

Music on a bottle:
I'm undertaking a special project that is linked to an album release. One of the tracks will be cut onto a bottle that can be then played at various venues.

My special effects company "Gyro Constructivists" have the job of realising the brief.

After a few weeks investigating the feasibility of the idea we took on the challenge.

Being aware the we can't cut into a glass bottle we intend machining one from solid acrylic, using acrylic tube for the test cuts, and also explore the possibility of coating a bottle with a thermo sensitive layer, perhaps epoxy resin, or a nitro-cellulose paint as has been the industry standard since the 1940's.

Having seen footage of hard drive actuator arm play music when connected to the headphone out socket or speaker cables I decided this would be the best approach. Reasons being, readily available at no cost, all components are very high quality, driven by a voice coil, gives true mono motion, plus the irony of using what is effectively a digital component to create an analogue sound.

The hard drive actuator arm from now on referred to as the "cutting head" will be mounted on an arm will traverse the bottle mounted to the lathe carriage . The bottle mounted on a computer controlled lathe that will allow precise control of rotational speed for optimum recording quality.

Making a mono recording allows for higher levels with less chance of the stylus skipping.

Playback of device for the bottle:
Comprising sourcing of a linear tracking tone arm mounted above the cylinder using a lathe similar to unit in the cutting process.

~~~~~~~~~~~~~~~~~~~~~~~~

4 weeks later and 300 hours later.

Descrbed below some of the key element of the build.

Cutting head and arm:
We stripped 8 hard drives down the ascertain the most appropriate arm for our application.

The arm from 4"drive as opposed to 2.5" drive allows more current resulting in greater amplitude.

We built three versions of cutting head getting improvements at every step finally eliminating the bearing all together using a machined piece of flat aluminium clamped to the head between rubber shims. Discovered that the bearing the arms typically have a harmonic resonance at around 8khz as described in a patent, a spring steel sleeve is used to remove the resonance , as we discovered upon stripping the drives.

Cutting tip: 
Having spent the first 3 weeks of the project doing test cuts with a standard playback tip we were not getting a good retrieval of the upper frequencies 6khz. We have opted to use a microgroove cut for a few reasons, mainly we get a much better high frequency response from the cut and we can get a little over 3 mins of audio onto the bottle rather than less than 2 minutes a standard groove. Also the downforce is much less resulting in less heat input to the cutting tip and less current required, the coils on the head were smoking in some tests!

Also mounted a cartridge with the stylus resign on the end of the cutting tip so we can moniter the audio as it's being cut and are able the make a direct comparison between the two.

We tried tungsten steel with is too hard to sharpen, so high-speed steel which allows get a very clean mirror resulting in a very quiet cut.  We also have a sapphire tip which we are not using for cutting as we only have one, and given the fragile nature we are using it as our reference only. Final cutting and polishing is carried out under a microscope.

Heating the tip: Heating the tip wound with NiChrome wire resulted in a smoother cut, requiring less downforce and reduced surface noise.
Every time the downforce and or cutting speed is adjusted the current supplied to the tip requires recalibration.

Spring vs Damping: To control the actuator's movements, damping was attempted with various materials, but this removed high frequencies around the 8khz, a more powerful spring was able to temper the actuator's large movements without reducing fast ones.  However it did introduce resonances and harmonics which were removed by reducing those frequencies with equalisations prior to recording.
We experimented with damping he cutting head initially with blue tack, then a silicone oil bath mounted to the arm with a paddle attached to the head, this being easily tuneable by adjusting the size of the paddle and viscosity of the silicone.
Adding up to a kilo of ballast also made improvements.

Surface Substrates and coatings
Initially we cut onto polycarbonate and acrylic to test the feasibility of using a hard drive actuator this proved the principle but a lot of surface noise present.
We spent the first few weeks of test cuts onto an acrylic platter coated in multiple layers of Nitrocellulose paint as it was a faster way of doing a lot of test cuts.

Standard acrylic automotive paint proved reasonably successful but still had a tiny amount of surface noise. Clear nitrocellulose was successful once a good ratio of castor oil was established again through trial and error. 

Cutting Speeds: Many of the above developments gave us incremental improvements to upper frequency ranges, but we achieved a huge improvement by recording at a quarter speed, and subsequently 1/8 speed. This way the cutter head didn't need to achieve these high frequencies in real time in order to cut them onto the record. 
Also using a vacuum to remove the cutting swarf as it's very hard to remove from the tip once it"s baked on from the heat.

We applied the RIAA equalisation curve reduces low and increases high frequencies using a filter in Garadgeband for recording and is reversed by the phono input in playback. Further equalisation was added for removing resonances and harmonics in the head and arm.

Cutting files:
Tone Sweeps of 50hz>1000khz used for most test cuts

Next steps:
Fitting a motor with speed lock encoder sourced from a laser cutter.
Commence build of the playback deck.

The first cut to a coated acrylic cylinder - Audio Link here:
https://dl.dropboxusercontent.com/u/11284652/Audio_First_Cut_to_Cylinder.aiff

Image links here:
http://www.facebook.com/media/set/?set=a.535032239876324.1073741825.248294555216762&type=1&l=e8388c3b37

More to come once we have the player under way.

Cheers Andrew@Gyro

[Angus McCarthy]

Encouraging results, Andrew!

[Gyro]

Finally got the project finished, see here on Vimeo:
http://vimeo.com/68007497

[markrob]

Hi,

Kudos on the project! Great video overview of the process. Really nice job of tackling all of the engineering challenges.

Mark