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Product: Audio: Record Player
Lissajous Pattern Record Grooves   (+5)  [vote for, against]
Let the pendulum mounted needle go, watch it play soothing music while following the interesting patterns.

The record would be parabola shaped. To cut it, a pendulum with a cutting needle would be set to swinging by releasing it from a position that exactly matches the release point on the player. It would go through the natural swinging patterns creating beautiful curves and patterns while the vibrating cutting needle imparted audio information to those patterns into this soft master disk.

Once the master is created, much harder playable records are cast from this. The record player has an exactly matching pendulum that's released from the exact same point as the cutting lathe so that it will approximate the lissajous pattern in its progression through the recording with slight deviations being corrected by virtue of it following the physical guide of the record notch.

Various patterns could be chosen as well by releasing the pendulum on lathe and player from different points with different approach angles. 4 or 5 choices would be available and the correct position would be marked on the record, although you'd quickly learn to recognize which pattern was cut into the record you're about to play.

Clearly very soothing music that would compliment the motion of the player would be a natural choice.

A more practical idea might be to adapt those swirly drawing contraptions like the one we played with as kids to a record player. Note, I believe the issue of interference with the path by having it constantly cross cut by subsequent passes would be to a large part due to the trajectory of the swinging player element but you might have to have the cut go continuously deeper from start to finish and the player pendulum similarly extend the needle deeper as it plays.

NOTE: This is one of those ideas that changed after writing it but I don't feel like going back and changing it. Have the machine in the first link be adapted rather than pendulum which has some issues. Although the pendulum would be relaxing to watch.

Ok, either of these approaches would work.
-- doctorremulac3, Sep 30 2019

Swirly needle path record player. https://www.youtube...watch?v=ygcGfnVM6Ho
[doctorremulac3, Sep 30 2019]

Orginal idea that I think would be better served with the machine above. https://www.youtube...v=v4gzuwaTHd0&t=88s
[doctorremulac3, Sep 30 2019]

YouTube: Anita Chowdry's "Iron Genie" harmonograph https://www.youtube...watch?v=Anl9R1MQlS0
Mentioned in my anno. A better-produced video, but doesn't show technical details. [notexactly, Oct 01 2019]

YouTube: Gavin Greenaway's homemade harmonograph https://www.youtube...watch?v=63TK_-defac
Mentioned in my anno. The video is just as homemade as the machine, but it shows lots of technical details and paths. [notexactly, Oct 01 2019]

YouTube: David Vernon Williamson's attempts to get consistent drawings from a harmonograph https://www.youtube...watch?v=oaMsz0tfliw
Mentioned in my anno. No two drawings quite the same, even with careful control of the conditions. [notexactly, Oct 01 2019]

YouTube: Alfred Hoehn's pantograph-type drawing machine https://www.youtube...watch?v=akI78l1gXkU
Mentioned in my anno. I don't know if this type has a proper name, but I've seen it called a harmonograph too. (I've also seen it referred to as a type of guilloché machine, but I don't think it's ever actually been used for that). [notexactly, Oct 01 2019]

YouTube: Francisco Nieva's (?) pantograph-type drawing machine https://www.youtube...watch?v=QTqyIPHbAPA
Mentioned in my anno. This one has multiple pens tracing different paths simultaneously, which could be interesting musically. It also has an epicyclic drive mechanism for the pantograph. [notexactly, Oct 01 2019]

Doesn't a pendulum swing through a spherical surface, not a paraboloidal one, unless its cord is restricted by some kind of curvedly tapered tube?

I think a non-contact storage/reading method (optical, magnetic, capacitive?) might be more appropriate for this, because, that way, there's no risk of the needle taking the wrong path when the tracks overlap and then diverge again. The risk of that is a lot less with the Spirograph™-like mechanism (which I what I think you're referring to in the last substantive paragraph), because the mechanism enforces a particular path for the needle. With such a mechanism, though, each record would be limited to playing back only the tracks recorded, and it would have to be supplied with the settings for the geometry of the player. On the other hand, with the pendulum, assuming non-contact reading, the head could be allowed to roam freely over the record, as a pendulum does, and it would produce sounds based on whatever it passed over. Then there would be an art to composing records that would produce interesting sounds in that way, and there would also be an art to setting the pendulum swinging on a given record—almost like a form of DJing. Also, if you left it swinging for an hour or so, the sound output would also depend noticeably on your latitude.
-- notexactly, Sep 30 2019


//Spirograph™//

Wowwww. You could record music by having a little transducer driving a cutting needle in a Spirograph pen on a piece of vinyl.
-- MaxwellBuchanan, Sep 30 2019


Very nice.
-- Loris, Sep 30 2019


//risk of the needle taking the wrong path when the tracks overlap and then diverge again.//

That's why I opted for the spirograph version halfway through the idea. The mechinism leads the way, not the groove itself.

If I had a spare couple of tens of thousands I could throw away on a weekend project I would create and market these. Annual unit sales would be projected to be in the hundreds if not dozens, but that wouldn't be the point.

It would be like my hero the guy who was instrumental in the design of two of my favorite things, the A-10 Warthog and the F-16 Fighting Falcon. He owns a Jazz record label now. He said he licenced something to JayZ for a hit song and that pays for all his other jazz albums that lose money. This guy is about as close to a god as you can get without wearing sandals and having a beard.
-- doctorremulac3, Sep 30 2019


//non-contact// definitely. Friction would not be your friend in this.
//mechanism leads the way// the 2D pendulum is "the mechanism" leading the way too. Heavy weight, good (magnetic repulsion?) bearings at the top.
//extend the needle deeper// I think lowering the whole mechanism from the top would be easier, and keeps the geometry of the pendulum precisely constant (but not needed if you go non-contact...).

(Re: the cycloid drawing machine; many years ago I wrote a Q-BASIC program that did the same thing, only better.)
-- neutrinos_shadow, Sep 30 2019


I likey (+)
-- 2 fries shy of a happy meal, Sep 30 2019


As an alternative to a Foucault-esque pendulum, I suggest looking at harmonographs: [links]. That way, the pattern can be more complex and, more importantly, you can use a planar record while keeping the head in contact/proximity.

// pendulum […] good (magnetic repulsion?) bearings at the top. //

I suggest a knife-edge gimbal. Maglev requires active control, and will impart vibration to the pendulum.

As an alternative, there are also pantograph-style drawing machines: [links]. That mechanism seems like it would produce a more repeatable pattern, as long as the two cranks were geared together and driven by the same motor.
-- notexactly, Oct 01 2019


//active control//
?
A couple of repelling permanent magnets; no activity needed.
-- neutrinos_shadow, Oct 01 2019


Take it up with Earnshaw.
-- notexactly, Oct 02 2019


(Quick googling)... Hmm; you learn something every day.
(On the other hand, how did I not know about Earnshaw already?)
-- neutrinos_shadow, Oct 02 2019


//(On the other hand, how did I not know about Earnshaw already?)//

You had a fever that day and Steven Cooper, who was supposed to be taking notes for you, used his hall pass to skip the last quarter of that class to chat up Melanie Slatinger and you never got the info.

Next question please, or if you would be so kind as to pay the receptionist on your way back... and thank you for visiting the Deuxfrites metaphysical Akashic recording studio and Ideaological emporium.
Have a nice day.
-- 2 fries shy of a happy meal, Oct 02 2019


//Deuxfrites metaphysical Akashic recording studio and Ideaological emporium//
I would ask for a business card, but I don't think all that will FIT on a business card.
-- neutrinos_shadow, Oct 03 2019


The struggle is real.
-- 2 fries shy of a happy meal, Oct 03 2019



random, halfbakery