I forgot to mention that in the "tones part" in my uploaded last mp3, there is too much harmonic distortion, mostly in 440Hz (A4) and above...
Why do you think this is happening?
Regards,
Sifis
My home made lathe
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grooveguy
- Posts: 431
- Joined: Thu Jun 22, 2006 5:49 pm
- Location: Brea, California (a few miles from Disneyland)
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Re: My home made lathe
Hi, Sifis,
In the video you linked to, it's really hard to tell much about how the stylus is driven. The speaker frame is in the vertical plane, so the motion should be in the right direction, but the coupling between the speaker and the stylus isn't clear in the video. Your sketch of the speaker you are using is a bit confusing because the speaker is drawn horizontally, with the motion shown up and down. To feel comfortable about what you are doing, either a better photo or a sketch showing the plane of the disc, how the driver is mounted, and how the motion from the driver voice coil is coupled to the embossing stylus.
As for the 'downforce weight,' this is a factor more for tracking the record in playback; that is, are you pushing the stylus deep enough into the disc to create a groove that can be played? Here's a quick sketch of how I see that this needs to be:
In this sketch, the Carriage is what is driven from the right to the left by your feedscrew mechanism. The Speaker frame is mounted firmly to the carriage. The voice coil of the speaker, which has low mass, is coupled to a lever, which is pivoted close to the Disc surface. Motion 1 and Motion 2 of the voice coil cause the opposite and smaller Motion 1 and Motion 2 of the stylus. The pivot for the lever is fixed firmly to the carriage as well. It is important that the stylus is anchored securely just above the surface of the disc. This is nearly identical to the 'soundbox' of an old acoustic phonograph:
In the drawing of your lathe, it looks as though the stylus is fixed to the frame of the speaker. I don't understand this, as the voice coil is what is moving in response to the signal.
In the video you linked to, it's really hard to tell much about how the stylus is driven. The speaker frame is in the vertical plane, so the motion should be in the right direction, but the coupling between the speaker and the stylus isn't clear in the video. Your sketch of the speaker you are using is a bit confusing because the speaker is drawn horizontally, with the motion shown up and down. To feel comfortable about what you are doing, either a better photo or a sketch showing the plane of the disc, how the driver is mounted, and how the motion from the driver voice coil is coupled to the embossing stylus.
As for the 'downforce weight,' this is a factor more for tracking the record in playback; that is, are you pushing the stylus deep enough into the disc to create a groove that can be played? Here's a quick sketch of how I see that this needs to be:
In this sketch, the Carriage is what is driven from the right to the left by your feedscrew mechanism. The Speaker frame is mounted firmly to the carriage. The voice coil of the speaker, which has low mass, is coupled to a lever, which is pivoted close to the Disc surface. Motion 1 and Motion 2 of the voice coil cause the opposite and smaller Motion 1 and Motion 2 of the stylus. The pivot for the lever is fixed firmly to the carriage as well. It is important that the stylus is anchored securely just above the surface of the disc. This is nearly identical to the 'soundbox' of an old acoustic phonograph:
In the drawing of your lathe, it looks as though the stylus is fixed to the frame of the speaker. I don't understand this, as the voice coil is what is moving in response to the signal.
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Re: My home made lathe
Thanks for the reply and the advices grooveguy.
After long reading of building DIY cutterheads, I realise that I need to built a new cutterhead, according to your sketch.
I decide to use some plastic couplings from the centre of the frame of my visaton driver and maybe a brass torque tube to hold the stylus.
I saw this amazing video (https://www.youtube.com/watch?v=s62GfJEr6PI) that epicenterbryan explains the motions of the stylus.
So, I 'll try to built a MONO cutterhead according to these principles.
One thing to ask:
I use number 3 of these stylus: http://www.ebay.co.uk/itm/Record-lathe-cutter-presto-record-in-stylus-needle-styli-rek-o-kut-recorder-/281255271864?hash=item417c1eddb8:g:JF0AAOSwDN1UUHTk
Is it necessary to have a 22-25 degrees angle from the vertical? As I see the "ZEZcutter" and "GrooveScribe" doesn't has any angle. Or am I wrong?
Second query: What material do you think it will work better to use for couplings, to the frame of my driver? (http://www.visaton.com/en/industrie/koerperschall/ex45s_8.html)
Plastic borns lot of resonances? Is it better to use aluminium cone?
Regards,
Sifis
After long reading of building DIY cutterheads, I realise that I need to built a new cutterhead, according to your sketch.
I decide to use some plastic couplings from the centre of the frame of my visaton driver and maybe a brass torque tube to hold the stylus.
I saw this amazing video (https://www.youtube.com/watch?v=s62GfJEr6PI) that epicenterbryan explains the motions of the stylus.
So, I 'll try to built a MONO cutterhead according to these principles.
One thing to ask:
I use number 3 of these stylus: http://www.ebay.co.uk/itm/Record-lathe-cutter-presto-record-in-stylus-needle-styli-rek-o-kut-recorder-/281255271864?hash=item417c1eddb8:g:JF0AAOSwDN1UUHTk
Is it necessary to have a 22-25 degrees angle from the vertical? As I see the "ZEZcutter" and "GrooveScribe" doesn't has any angle. Or am I wrong?
Second query: What material do you think it will work better to use for couplings, to the frame of my driver? (http://www.visaton.com/en/industrie/koerperschall/ex45s_8.html)
Plastic borns lot of resonances? Is it better to use aluminium cone?
Regards,
Sifis
-
grooveguy
- Posts: 431
- Joined: Thu Jun 22, 2006 5:49 pm
- Location: Brea, California (a few miles from Disneyland)
- Contact:
Re: My home made lathe
Hello, Sifis,
Now that I see what Visaton driver you are using, the problems you have become somewhat more clear. I have not followed different experimenters' cutterheads very closely, but feel that you would have more success using a more conventional 'loudspeaker' type of driver motor. Your Visaton unit is meant to excite surfaces in the manner you see in advertisements that say, "Make the walls of your house into a loudspeaker." That type of driver works only against its own mass. Picture this: if you were to stand next to an open door, hold the knob and push it back and forth, the door would respond exactly as you push and pull. This is because you are standing on the solid floor and can exert force against the door as you push and pull it. Now imagine yourself on roller skates or sitting in a office chair with wheels. You are not anchored to the floor, so as you now push and pull the knob, you are likely to waste a lot of your energy in moving yourself back and forth. Because you have greater mass than the door, you will still move it, especially when you push and pull very fast (high frequencies). Nonetheless, some of your energy is spent in moving your body as well as the door.
This is what your driver might be doing unless you have some means of clamping the other side of it securely and attaching that side to the carriage that your feedscrew moves across the record plane. Especially with that driver, the mass of the plate that vibrates is far greater than the mass of your stylus, which limits high frequency response. And if the back side of the driver is not anchored, that will limit your low frequency response.
I would make some experiments with a typical loudspeaker, much as the fellow did in this YouTube video:
http://www.youtube.com/watch?v=pcCsAzHoSpQ
You could use a simple loudspeaker from an old transistor radio. The aluminum cone is simply a low-mass means of coupling the energy from the outside diameter of the voicecoil, so that the voicecoil does not twist, as it might if you took the energy from just one point.
As for the inscribing angle, if you are cutting a groove, the stylus wants to be vertical. Embossing apparently requires an angle, and 20 degrees seems to be a popular one, except that Norman Field (search on YouTube) has had very good success with a near-vertical stylus while using a lubricant. This is something you can experiment with after you are able to emboss a groove successfully, like in the YouTube link above.
Sorry, but I will be out of town at a broadcasters' convention for the next week, but will check back with you afterward to see what progress you have made. Good luck!
Now that I see what Visaton driver you are using, the problems you have become somewhat more clear. I have not followed different experimenters' cutterheads very closely, but feel that you would have more success using a more conventional 'loudspeaker' type of driver motor. Your Visaton unit is meant to excite surfaces in the manner you see in advertisements that say, "Make the walls of your house into a loudspeaker." That type of driver works only against its own mass. Picture this: if you were to stand next to an open door, hold the knob and push it back and forth, the door would respond exactly as you push and pull. This is because you are standing on the solid floor and can exert force against the door as you push and pull it. Now imagine yourself on roller skates or sitting in a office chair with wheels. You are not anchored to the floor, so as you now push and pull the knob, you are likely to waste a lot of your energy in moving yourself back and forth. Because you have greater mass than the door, you will still move it, especially when you push and pull very fast (high frequencies). Nonetheless, some of your energy is spent in moving your body as well as the door.
This is what your driver might be doing unless you have some means of clamping the other side of it securely and attaching that side to the carriage that your feedscrew moves across the record plane. Especially with that driver, the mass of the plate that vibrates is far greater than the mass of your stylus, which limits high frequency response. And if the back side of the driver is not anchored, that will limit your low frequency response.
I would make some experiments with a typical loudspeaker, much as the fellow did in this YouTube video:
http://www.youtube.com/watch?v=pcCsAzHoSpQ
You could use a simple loudspeaker from an old transistor radio. The aluminum cone is simply a low-mass means of coupling the energy from the outside diameter of the voicecoil, so that the voicecoil does not twist, as it might if you took the energy from just one point.
As for the inscribing angle, if you are cutting a groove, the stylus wants to be vertical. Embossing apparently requires an angle, and 20 degrees seems to be a popular one, except that Norman Field (search on YouTube) has had very good success with a near-vertical stylus while using a lubricant. This is something you can experiment with after you are able to emboss a groove successfully, like in the YouTube link above.
Sorry, but I will be out of town at a broadcasters' convention for the next week, but will check back with you afterward to see what progress you have made. Good luck!
Re: My home made lathe
Hi again grooveguy,
Well, I know that this driver works against its mass. That's why I glue it (with silicone), in a piece of plastic that is holded in the main carriage of my tonearm. Silicone is hard enough to hold it in place. Also, as you can see in pics, there is a piece of foam between the plastic and the back side of the driver.
However, I understand that the plane of the driver, has too much mass. Also, I understand that if I'm pushing it against a surface from the back side, it's getting louder. (that's why I realise that the driver works against its mass).
Anyway, as I said in a previous post, maybe I should quit this driver and I try some other one.
Well, I know that this driver works against its mass. That's why I glue it (with silicone), in a piece of plastic that is holded in the main carriage of my tonearm. Silicone is hard enough to hold it in place. Also, as you can see in pics, there is a piece of foam between the plastic and the back side of the driver.
However, I understand that the plane of the driver, has too much mass. Also, I understand that if I'm pushing it against a surface from the back side, it's getting louder. (that's why I realise that the driver works against its mass).
Anyway, as I said in a previous post, maybe I should quit this driver and I try some other one.
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Re: My home made lathe
Hi there,
Well, while I was looking for my next driver, I found this one (https://abra-electronics.com/electromechanical/audible-devices/speakers/spk-trans-l-surface-transducer-large-spk-trans-l.html)
and this one : http://www.daytonaudio.com/index.php/loudspeaker-components/loudspeaker-drivers-by-series/exciters/bct-2-45-x-25mm-bone-conducting-transducer.html
The first was used by EpicenterBryan for his GrooveScribe project. Because I can't find it in Europe, I decide to buy the second one, of Dayton Audio.
Grooveguy, I don't want to try just a speaker from an old transistor for example, because I don't know a lot about speakers.
I believe that this kind of drivers, has much benefits so to build it and connect with a torque tube.
However, I don't know exactly how it works.
Does anyone uses this exact driver?
Also, does anyone knows about how the driver oscillates? Is it the coil-magnet mechanism ONLY expands and contracts the center shaft?
Or it creates vibration to the hole body of the unit?
Any advice or comments are welcome
Regards,
Sifis
Well, while I was looking for my next driver, I found this one (https://abra-electronics.com/electromechanical/audible-devices/speakers/spk-trans-l-surface-transducer-large-spk-trans-l.html)
and this one : http://www.daytonaudio.com/index.php/loudspeaker-components/loudspeaker-drivers-by-series/exciters/bct-2-45-x-25mm-bone-conducting-transducer.html
The first was used by EpicenterBryan for his GrooveScribe project. Because I can't find it in Europe, I decide to buy the second one, of Dayton Audio.
Grooveguy, I don't want to try just a speaker from an old transistor for example, because I don't know a lot about speakers.
I believe that this kind of drivers, has much benefits so to build it and connect with a torque tube.
However, I don't know exactly how it works.
Does anyone uses this exact driver?
Also, does anyone knows about how the driver oscillates? Is it the coil-magnet mechanism ONLY expands and contracts the center shaft?
Or it creates vibration to the hole body of the unit?
Any advice or comments are welcome
Regards,
Sifis