ANGLING FOR 90 - tangential pivot tonearms - Page 34 - diyAudio
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Old 11th February 2012, 03:32 PM   #331
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To Esperado. Sure, a smart engineer with good background in electronics will be able to create perfectly tracking electronically guided arm (there are already a lot of them), possibly even a better one, than most of mechanical ones. However, mechanically inclined hobbyists here are trying to achieve that task mechanically, for a reasonable cost, and sonically it supposed to be above the average level of industrial items, that is pretty realistic task.
And let's have some fun, besides...

Last edited by walterwalter; 11th February 2012 at 03:39 PM.
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Old 11th February 2012, 03:41 PM   #332
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Quote:
Originally Posted by Esperado View Post
Or forget about all those museum's old analog problems and have a look to the Digital solutions offered by our century to record, preserve and reproduce music . ...Thousand time better... Not so good looking...
Thanks for the pointers. But... hmm... last time I checked, this forum is for "analogue source." Am I right or am I missing something here?
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Old 11th February 2012, 04:45 PM   #333
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Here is another fun item: "Mag-Lev/Hydraulic Vertical Piston Linear Tonearm" by SimplyPhysics. On their web-page, here's how they describe this prototype tonearm:

Quote:
Work is underway on the nextgen of innovation, a maglev linear tracking & "armless" design (pictured below). It's sans an “arm” tube or wand, utilizing a vertical hydraulic piston with internal magnetic dampening. The stylus cannot leave perfect tangent & the piston is sans relative mass, only tracking force. It cannot “teeter-totter" as in pivoting or linear tracking "armed" designs. No other design maintains perfect vertical tangent and azimuth alignment, and it's linear maglev!
Click the image to open in full size.

The turntable looks interesting too but let's just focus on the arm. It's a purely mechanical design, with NO air-bearing, no motor, no sensor, no electronics, and no power supply. Extremely low mass, low friction...almost sounds like a mechanical ideal... but will the implementing of magnet affect the cartridge by the magnetic force since the cartridge body is so close to the magnetic rail and that magnetic "piston" bearing. The basic question is that are the magnets well shielded? How rigid is that thin cushion of magnetic force between the maglev rail and the arm assembly--much the same concern with air-bearing? And how well does the "vertical hydraulic piston" bearing work in terms of friction and movement? It's an intriguing design and we have to wait and see if this prototype will actually work when it comes out in the market. I have my doubts because so far all I see is just a drawing. Another concern is how is VTA or, more importantly, SRA is adjusted since there's no "teeter-tottering" and only vertical motion, I hope there's something at the headshell area that allows for the SRA, stylus rake angle.

If this type of pistonic bearing works, it can be applied to many other designs for good use since it eliminates the vertical bearing at the armbase. I can imagine using that on a Dynavector tonearm with its "split plane" design. Or the below arm...

Click the image to open in full size.

Click the image to open in full size.

Now that weird arm above reminds me of the Vestigal tonearm:

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Click the image to open in full size.

Another tonearm that inhibits vertical motion at the base is the Loci tonearm:

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Click the image to open in full size.

.

Last edited by directdriver; 11th February 2012 at 04:53 PM.
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Old 15th February 2012, 05:55 PM   #334
stevieg is offline stevieg  United Kingdom
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Quote:
My old Dad used to say that the Vincent motorcycle was a collection of solutions looking for a problem.
My Dad's point was that you can overengineer to the point of unuseabilty/unintelligibility. My problem with the extremely complex behemoth approach is that if you just want to spin a few tunes on the turntable, it should be a relatively simple activity. I think turntable are similar to bicycles - perfection is easy to design; trouble is, you then have to fit a human in there...

Nanook's twin single pivot idea has merits; the fewer the bearing the fewer things to rattle. Also the wire guided swinging headshell.

Still loving this thread, but have a need to spin some Warren Zevon. Bye!

Cheers Steve
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Old 15th February 2012, 07:35 PM   #335
Nanook is offline Nanook  Canada
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Default twin pivot approach...

Quote:
Nanook's twin single pivot idea has merits; the fewer the bearing the fewer things to rattle. Also the wire guided swinging headshell.
Even simpler (although not a tangential pivoting tonearm at all!) is my 219, which is about as dumb stupid easy as you can get.

Quote:
Still loving this thread, but have a need to spin some Warren Zevon. Bye!
And in this hobby what's the point if we don't actually love listening to music!
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Old 27th February 2012, 08:43 PM   #336
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Default BJ tonearm

Some rare photos of the Burne-Jones tonearm.

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Click the image to open in full size.

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Old 27th February 2012, 10:06 PM   #337
Nanook is offline Nanook  Canada
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Default still thinking of dual pivots...

As I have stated all along in this thread and others, when one has to engineer a solution, it is usually the simplest version that comes out ahead. Not always (there are always creative means to an end), but usually.

The simplest articulating tonearm that could offer near tangential tracking is most probably the Thales arms or those that use the same principles (I'm sure if we look hard enough the Garrard "Zero" arm may be able to be shown that it relies on similar mathematics. The "hung cartridge as pictured in DD's last post may simply have to much play, or else adjusting the play out could be very tedious and time consuming. I was (and am) of the opinion that a cartridge should be mounted as firmly to the tonearm/headshell as possible, if for no other reason to control the geometry.

I have the pieces from 2 Sugden tonearms that could allow me to experiment with a Thales concept. The most difficult part would be making a pivoting "headshell" or mounting plate. And of course the arm would be something like 12" long as well
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Old 28th February 2012, 12:51 AM   #338
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Default great thread...

I sold a Zero 100 to an elderly neighbor years ago for 20 bucks, which is what I paid for it at a thrift store. I'd like it, or another one, back because I'd like to know if it maintains a consistent offset, which the B-J definitely does not, or a progressively decreasing offset, a la Van Eps or Warden. Just missed a Garrard on CL for $35. Sorry; I'm not one of those big spenders who keep hifi going. Off to VE to see if the Garrard thread can answer this for me. My limit is $5 per item unless it's very special.
Still, that's more than $2.19.
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Old 28th February 2012, 05:05 AM   #339
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Quote:
Originally Posted by Nanook View Post
The "hung" cartridge as pictured in DD's last post may simply have to much play, or else adjusting the play out could be very tedious and time consuming.
Those hanging cartridges are not to be taken seriously. I got those images from a Russian site that, even with rough translation, they are supposed to be concept prototypes that never materialized into actual products. They are merely concepts and, for me, provided visual entertainments, just like this entire thread.

I am quite aware of simplicity and structural integrity in a tonearm design but balancing that with ingenious use of geometry, bearings, and guiding mechanism is no mean feat. It sure is fun to think about them for me.

My Kenwood KD-770D turntable is broken so I might salvage its tonearm and it has a straight armwand with a detachable headshell that has an offset angle. I might replace the headshell with a conventional straight headshell that I can add a pivot with a ball bearing a la RS Labs and also come up with some guiding mechanism for quasi-tangential tracking. I am curious where this will lead to.

Nanook, I look forward to your experiment.
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Old 28th February 2012, 08:17 AM   #340
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Originally Posted by phivates View Post
I sold a Zero 100 <snip> I'd like it, or another one, back because I'd like to know if it maintains a consistent offset, which the B-J definitely does not, or a progressively decreasing offset, a la Van Eps or Warden.
The concept of offset makes no sense when applied to tangential tracking tonearms.
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