You might like to see a (daft) idea I came up with many years ago for minimising tracking error. www.koolkatz.biz - Audio. Never developed it so don't really know how effective it would have been.
Pivoting, Sliding, Tangential Tone Arm
Hello Direct Driver,
I just discovered your thread concerning tangential tone arms.
I'm amazed as to how one individual can find that much information
on this subject.
In the early eighties I patented a tone arm as you suggest.
It was a sliding, pivoting, tangential arm. My patent covered a purely
mechanical version and a motorized version. I built a prototype of the
motorized version, which functioned fine. Because of the fact that CDs
came on the market about this time, I decided not to build the mechanical
version of that arm. Three years ago I found out that vinyl was still very
much alive and I decided to resurrect my tone arm and give it another try.
The first arm was designed on the drawing board, while the one I'm working on now was designed with CAD software which I had learned in
the meantime.
The arm is straight, no offset. Its length is 7.950" and its pivot is attached to a carriage which rolls on a track which is 1.550" long.
The track's centerline is in line with the center of turn table platter.
Hello Direct Driver,
I just discovered your thread concerning tangential tone arms.
I'm amazed as to how one individual can find that much information
on this subject.
In the early eighties I patented a tone arm as you suggest.
It was a sliding, pivoting, tangential arm. My patent covered a purely
mechanical version and a motorized version. I built a prototype of the
motorized version, which functioned fine. Because of the fact that CDs
came on the market about this time, I decided not to build the mechanical
version of that arm. Three years ago I found out that vinyl was still very
much alive and I decided to resurrect my tone arm and give it another try.
The first arm was designed on the drawing board, while the one I'm working on now was designed with CAD software which I had learned in
the meantime.
The arm is straight, no offset. Its length is 7.950" and its pivot is attached to a carriage which rolls on a track which is 1.550" long.
The track's centerline is in line with the center of turn table platter.
Attachments
I've been out of the loop on this thread. Wow, Straight Tracker, that's a fascinating tonearm! Please tells us more about this and elaborate on the mechanism. Is the one in the picture a mechanical arm or a motorized one? I notice there's no pivot at the headshell, (good idea) so I take it to keep tangency, the armwand has to be able to lengthen and shorten according to pivoting of the arm to stay in the geometry of the Thales semi-circle. My complaint of the other arm is that the pivot is at the headshell and that might create too much vibration so close to the cartridge and the added mass. By shifting the extra pivot closer to the armbase can be beneficial but require more complication in the design. I'm glad someone has done it and made it work! More pictures please!
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I found more better pictures of that mysterious DIY string tonearm. Check it out. Very clever design and I love its simplicity.
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I found more better pictures of that mysterious DIY string tonearm. Check it out. Very clever design and I love its simplicity.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
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The concept of the articulating headshell to reduce or eliminate tangential tracking error is at least 40 years old. That's how old Garrard Zero 100 is. It never caught on. Other steps to reduce or eliminate effects of it were the invention of the eliptical stylus and anti-skating force application.
The problem of reducing angular tracking error is that you may be trading off obtaining a solution for a small problem at the cost of creating a much more serious one, namely hugely increasing the dynamic mass and lowering the compliance of the stylus suspension/arm bearing system. All of the force required to move the tonearm including the articulating headshell comes from the force exerted by the soft vinyl against the diamond stylus. The greater that force has to be to overcome inertial mass, the faster the record will wear out because the pressure (force divided by contact area) increases. If you are going to use an articulating headshell, a conical or hypereliptical stylus is probably best because it increases the contact area and reduces stress. Eliptical and microridge stylus geometries increase it. Once the stress increases beyond the modulus of elasticity of the vinyl, it remains permanently deformed and the record groove is degraded. This is especially likely at higher frequencies and higher modulations where the force is greatest. If the force is sufficient to cause the stylus to lose contact with the groove even momentarily, it will come crashing back down into contact with it also likely damaging it. Therefore it is not wise to use insufficient tracking force for a particular arm/cartridge combination.
Reducing dynamic mass, increasing compliance, and assuring critical damping of the mechanical system were IMO the goals of the best tonearm/cartridge designers. This increased usable record life and reduced distortion more effectively than any other approach. Unfortunately, the overwhelming majority of tonearms are only statically balanced relying on an imbalance of mass around the pivot points to apply tracking force.
The problem of reducing angular tracking error is that you may be trading off obtaining a solution for a small problem at the cost of creating a much more serious one, namely hugely increasing the dynamic mass and lowering the compliance of the stylus suspension/arm bearing system. All of the force required to move the tonearm including the articulating headshell comes from the force exerted by the soft vinyl against the diamond stylus. The greater that force has to be to overcome inertial mass, the faster the record will wear out because the pressure (force divided by contact area) increases. If you are going to use an articulating headshell, a conical or hypereliptical stylus is probably best because it increases the contact area and reduces stress. Eliptical and microridge stylus geometries increase it. Once the stress increases beyond the modulus of elasticity of the vinyl, it remains permanently deformed and the record groove is degraded. This is especially likely at higher frequencies and higher modulations where the force is greatest. If the force is sufficient to cause the stylus to lose contact with the groove even momentarily, it will come crashing back down into contact with it also likely damaging it. Therefore it is not wise to use insufficient tracking force for a particular arm/cartridge combination.
Reducing dynamic mass, increasing compliance, and assuring critical damping of the mechanical system were IMO the goals of the best tonearm/cartridge designers. This increased usable record life and reduced distortion more effectively than any other approach. Unfortunately, the overwhelming majority of tonearms are only statically balanced relying on an imbalance of mass around the pivot points to apply tracking force.
Reply to Direct Driver
My patent covered a motorized version and a version that was driven by friction. The one in the picture is the motorized version. The one I'm building now is driven by friction. The motorized one uses an Airpax 15 degree stepping motor. The arm is dynamically balanced an its pivots are mounted on a carriage which travels on a track whose centerline runs through the center spindle of the turntable. The track is only 1.550" long! the track is located in an overhead housing which makes the arm look mechanically busy. I started to make an improved version in the late eighties but abandoned it because it still had the overhead track. Lately I was able, with the help of CAD, to relocate the track into the base of the tonearm. It looks quite acceptable now.
My aim is to create the perfect tangential tonearm and not nessecarily the simplest. What I would like to do, is create a new Thread on this Tonearm because I have done a lot of research over the years and I have a complete photographic history which I would like to share.
My patent covered a motorized version and a version that was driven by friction. The one in the picture is the motorized version. The one I'm building now is driven by friction. The motorized one uses an Airpax 15 degree stepping motor. The arm is dynamically balanced an its pivots are mounted on a carriage which travels on a track whose centerline runs through the center spindle of the turntable. The track is only 1.550" long! the track is located in an overhead housing which makes the arm look mechanically busy. I started to make an improved version in the late eighties but abandoned it because it still had the overhead track. Lately I was able, with the help of CAD, to relocate the track into the base of the tonearm. It looks quite acceptable now.
My aim is to create the perfect tangential tonearm and not nessecarily the simplest. What I would like to do, is create a new Thread on this Tonearm because I have done a lot of research over the years and I have a complete photographic history which I would like to share.
Good luck on your patent. I know from first hand experience just how hard it is to make money or even get someone interested in a new idea.
It sounds like your motor assisted device should reduce the additional drag on the stylus considerably. I was referring to passive systems like Zero 100. While it can't be eliminated altogether so long as the stylus plays a role in pivoting the head shell, that drag could in principle be reduced very substantially. Have you considered other means which do not rely on the stylus such as a laser which tracks the center of the groove the way ADC Accutrac did for input to the stepping motor controller? Or you could use a laser to the distance to the edge of the record or the spindle to sense its position and adjust the headshell that way.
It sounds like your motor assisted device should reduce the additional drag on the stylus considerably. I was referring to passive systems like Zero 100. While it can't be eliminated altogether so long as the stylus plays a role in pivoting the head shell, that drag could in principle be reduced very substantially. Have you considered other means which do not rely on the stylus such as a laser which tracks the center of the groove the way ADC Accutrac did for input to the stepping motor controller? Or you could use a laser to the distance to the edge of the record or the spindle to sense its position and adjust the headshell that way.
Hello Soundminded
It is very hard to explain things properly in short blurbs. Actually my Patent has expired many years ago. The tonearm in the photo uses no side forces to make it track. There is an optical sensor made by Hewlett-Packard that controls the position of the arm. The version I'm building now, relies on friction in line with the centerline of the tonearm! Since I haven't finished it the idea remains a theory.
Tomorrow morning my Wife is going to scan additional photos etc. which I will post in a new thread. I think it will be much clearer then as to how the tonearm works.
I have looked into measuring distance with a laser, but found it to be very expensive. A company by the name of Keyence makes them. When I start my new thread, it will become apparent that the method I use to maintain position is quite effectve.
It is very hard to explain things properly in short blurbs. Actually my Patent has expired many years ago. The tonearm in the photo uses no side forces to make it track. There is an optical sensor made by Hewlett-Packard that controls the position of the arm. The version I'm building now, relies on friction in line with the centerline of the tonearm! Since I haven't finished it the idea remains a theory.
Tomorrow morning my Wife is going to scan additional photos etc. which I will post in a new thread. I think it will be much clearer then as to how the tonearm works.
I have looked into measuring distance with a laser, but found it to be very expensive. A company by the name of Keyence makes them. When I start my new thread, it will become apparent that the method I use to maintain position is quite effectve.
Its 00:35 and I've just read this thread through.
My fuzzy brain is telling me that the cartridge needs to be kept at a fixed angle to the centre of the platter - 90 degrees. So the easiest way would be to have something that connects to the spindle and tracks the cartridge at 90 degrees whilst it pivots on the arm tube.
My fuzzy brain is telling me that the cartridge needs to be kept at a fixed angle to the centre of the platter - 90 degrees. So the easiest way would be to have something that connects to the spindle and tracks the cartridge at 90 degrees whilst it pivots on the arm tube.
mmmmmmmm yup i was fuzzy wasn't I? i can see where i went wrong now.
I want a linear tracking arm
I have a Sony PS-4300 quartz timed direct drive on the way to play with. Might give Nanook's arm a go while trying something.
I now have in mind 2 small sections of aluminium with a very lightweight (maybe carbon fibre) under hanging carriage holding the cartridge that moves on ball races or similar... (Crazy thought about using balsa or polystyrene and floating the carriage for very low friction....
)
I want a linear tracking arm
I have a Sony PS-4300 quartz timed direct drive on the way to play with. Might give Nanook's arm a go while trying something.
I now have in mind 2 small sections of aluminium with a very lightweight (maybe carbon fibre) under hanging carriage holding the cartridge that moves on ball races or similar... (Crazy thought about using balsa or polystyrene and floating the carriage for very low friction....
)Reply to JRKO
I would not say you were "wrong". All ideas should be investigated. An arm like you suggest could feature a linear air bearing at the spindle and another linear air bearing at the arm pivot. But I would avoid the pivoting head shell. It seems that perfection is expensive. Having had a "Beer income and a Champaign taste" for most of my life, I tought myself machining skills and later CAD skills, so that I could mak the things I couldn't afford.
Ralf
I would not say you were "wrong". All ideas should be investigated. An arm like you suggest could feature a linear air bearing at the spindle and another linear air bearing at the arm pivot. But I would avoid the pivoting head shell. It seems that perfection is expensive. Having had a "Beer income and a Champaign taste" for most of my life, I tought myself machining skills and later CAD skills, so that I could mak the things I couldn't afford.
Ralf
It seems that perfection is expensive. Having had a "Beer income and a Champaign taste" for most of my life Hehehe I was 'living the rock star lifestyle on roady income'seems you were more sensible.
I tought myself machining skills and later CAD skills, so that I could mak the things I couldn't afford. Wish i had the skilz
Floating the cartridge maybe do-able - what's more fluid (viscous) than water but not dangerous that I could float the cartridge carriage on? oo oo whats that coolant they use for PC overclocking that is non conductive?
Let us not forget that it is Christmas and time to make a beard. You take a Fender Stratocaster from 59 sets a linn lp 12 turntable (the only thing that can be used) adds a Schreu engine with a **** (fuchs) tonenarm. This works with magnets in suspension so that the arm floats. How it sounds so. Timing, rhythm and musicality. Comparison Garrard o401 and Lenco l59. Please look at my pictures.
Merry Christmas Ole
Picasa Web Albums - ole slot - ole
Merry Christmas Ole
Picasa Web Albums - ole slot - ole
Hello Ole,
That's a strange looking CAPO attached to the second fret of that guitar.
Sincerely,
Ralf
RS Labs clone
One photo instead of introduction
http://i1230.photobucket.com/albums/ee496/jozo4/dual1940.jpg[IMG]http://i1230.photobucket.com/albums/ee496/jozo4/DSC01890.jpg
First picture is very old Dual record changer and second is some of my experiments with cloning of RS Labs arms or maybe better with Yamamura concept of arms.
Only thing in wich I am secure of from praxis in using this clones is that they need no any antiskating device, that track records very well and that they play the music.
One photo instead of introduction
http://i1230.photobucket.com/albums/ee496/jozo4/dual1940.jpg[IMG]http://i1230.photobucket.com/albums/ee496/jozo4/DSC01890.jpg
First picture is very old Dual record changer and second is some of my experiments with cloning of RS Labs arms or maybe better with Yamamura concept of arms.
Only thing in wich I am secure of from praxis in using this clones is that they need no any antiskating device, that track records very well and that they play the music.