Angling for 90° - tangential pivot tonearms

Adelmo,

Your arm looks better with each new version.

There’s a Dutch guy in Amsterdam who has a deal with Dutch customs - he gets all the bearings they confiscate.

Have you checked Italian ebay for bearings? Did you make a lighter wand?

If you used the Kuzma bearing arrangement, you would have to pay yourself $10,000.

Doug
hI,

I got all the parts for the new lighter wand, now need to find the time to finish it.

I also got the new parts for the ceramic bearings , also need to find the time to finish it.

Completed the TA lift.

Rgds

Adelmo


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Hi Adelmo,

Many years ago I did some testing of different bearings for my linear tracking arm.
I did try some full zirconia bearings. They were OK but not brilliant. Much better were the hybrid bearings from Boca bearings. These are silicon nitride and 440 stainless steel. They were about twice the price of the zirconia bearings but much lower friction and also much more consistent in friction as they rotated. More importantly they sound notably better.

Niffy
Hi Niffy,

I have careful assembled the ceramic bearings in the secondary shaft of my TA. I paid lore of attention to the bearing house allowance and also to the shaft. Must slide smooth but not tight not lose. I also pre load checking the best pre load for turning and no play.

Mechanically speaking it is better, also the new design make more easy to pre load bearings.

Changed the thread of the V motion bearing as I stressed them too much lately and play Rickie Lee Jones, Pirates, 1981 LP. I will not dare to say it sounds better yet but for sure not worse at all. I compared the same music since I have the same CD as well, but CD did sound too much worse. Hard to say, I think the CD have been poorly mastered comparing to the original LP.

In the end I will keep the things for a while as they are, in future I may try other bearings as suggested.


Tks n rgds

Adelmo
 
Greetings to all forum members and readers.

I want to support this topic.

I introduced myself in the "DIY linear tonearm" topic and will not introduce myself here.

I really like this topic and I read it completely a year ago.
Unfortunately, many photos do not open.

Over the past year, I have made about a dozen different designs of rotary tangential tonearms of my own design. About half of them failed.

I cannot boast of the brilliance of my tonearms like Carlo's. But they also work.

My tonearms are my toys.
These are experimental models from a hammer and chisel. And they do not have an external gloss.

Among them, there is one tonearm that I cannot call my own development.
I will show this tonearm here.

This design was inspired by the tonearm "Schroeder LT" by Frank Schroeder.
It's like a clone of the Schroeder LT, only turned inside out.
I even gave it the name "Aki Schroeder".

"Aki" in Old Russian means "as if".
I hope Frank won't be offended by me for this.

I tested this tonearm for about a month, listened to many records and it showed good performance.
It even passed records with large defects easily and effortlessly.
Large eccentricities are not a problem for it either.

I am showing a short video of the bearing moving along the guide with a large eccentricity.
I apologize for the low quality of the recording, but it clearly shows the movement of the bearing along the guide back and forth.

The first photo shows the needle movement trajectory with different guide sizes.

I hope to show other works of my own design in the future.

Best regards,
AG.
 

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Andrey,

If I understand your pivoting linear tonearm correctly, it entirely relies on stylus friction, frequently referred to as stylus drag (SD ) in threads on this forum.

Again, If I understand correctly, your design is unique and is a major accomplishment.

Doug
 
Again, If I understand correctly, your design is unique and is a major accomplishment.
Hi Doug

I am glad that you read my post and gave my design a high rating.
You flatter me, really.

But I don't think so.
In this design I only used my hands, not my head.
In my other designs the head worked first and then the hands.

You correctly noted that in this design the motor is only
the tip of the needle.
All my designs do not have any external energy sources
except the tip of the needle and the groove of the record. These are passive designs.

Perhaps in the future I will show my other designs.
They have a completely different concept of tonearm movement control.
But everything has its time.

I do not read or speak English, my native language is Russian.
I have to use an automatic translator, and different translators
give completely different translations, sometimes with opposite meanings.
So that I can understand you, and you can understand me, I ask you to give a list of abbreviations with a detailed
decryption.
And one more thing. Please keep your suggestions short and simple, so as not to give the translator a chance to distort the meaning.
Thank you in advance.

AG.
 
Interesting idea, Andrey, certainly innovative.
Unfortunately i am unable to understand how it works, despite your detailed photos.
So I tried to "mirror" an old simulation hypothesis of a cam driven PTTA, but i couldn't get the new one to respect the tangency condition in any way.
Could you please clarify how you designed the geometry? An inside out Schroeder is surely of great interest for everyone in this tread

ciao - carlo
 

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they are usual - mp4 videos - maybe downloading them may be opened by WIN itself, or other common appications.
But my failed attempt maybe is not important to explain me your geometry. thanks
c
 
Hi Andrey,
with a bit of reverse engineering on the photos, and seing the backlever under the wand, I think I got there to understand it (better late than ever!).
Works fine: brilliant, congratulations.
With your permission I could post that drawing, but yours will surely be better.
ciao carlo
 
Hi Hiten

I would be happy to answer your question if I understood it.
Please rephrase it so I can understand.
The translator is giving gibberish.

AG.
pardon me. I can not edit previous post. So here is fresh one.
-----------------------------------------------------------
What I was curious about is the surface on which the ball bearing rolls as show with red arrow in the picture.
Can it be made concave shape to reduce friction ? or is friction required to move the bearing ?
regards.
 
Hi,

Can you guys explain to me what are the advantage having the guiding cam in the opposite place comparing to the Frank Schroeder LT TA?. Sorry for asking but I am a bit slow understanding things.

Besides that this TA do not have the no contact mag cam but a contact friction cam.

Tks n rgds

Adelmo
 
With your permission I could post that drawing, but yours will surely be better.
No-no-no, draw it, please.
I don't know how to work on these simulators, and my grandson is a computer genius, he graduated from school a year agoand is now studying in another city. And I can only draw it on a piece of paper.
I'm glad you got to the point and saved me from explaining with the help of this damn translator.

AG.
 
Can it be made concave shape to reduce friction ? or is friction required to move the bearing ?
Thank you.
Now I understand your question.
The bearing rolls, not slides along the guide.
I think that the shape of the bearing surface, whether it is convex or concave, will not make much difference.
But I have not experimented with the shape of the surface.

AG.
 
Here my attempt of "reverse engineering" (sounds serious, isn't it?)- Hope i've been lucky to understnd. May you tell us the process to land on such solution?
c
 

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Excellent, Carlo!
Thank you very much.

The needle goes almost in a straight line, with a clockwise turn.
The perpendicular always points to the center of the record.

May you tell us the process to land on such solution?

Nothing special.
Just sleight of hand and no cheating.
I borrowed the idea from Frank Schroeder, only turned it inside out and removed the magnetic guide.
I don't like these magnets, I think that the base of the tonearm should have a rigid connection with the guide.
Although, maybe it doesn't matter much.

AG.
 

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Hi Andrey,

....I don't like these magnets, I think that the base of the tonearm should have a rigid connection with the guide.
Although, maybe it doesn't matter much.


I agree with you, mags are pretty tricky and not so easy to make them work well, especially in such tiny dimension. However I think the mag guide comparing to the rigid cam have some advantage when tracking eccentric LPs. They allow to well follow the LP eccentricity.

Best regards

Adelmo
 
Hello, Adelmo

I am glad that you read my words and reacted to them.
You disagree with them and that is good. You think one way, and I think another.
And each of us has no evidence that we are right.
And where is the truth?

That is where I came up with the idea of conducting a simple experiment with you,
which will bring us closer to understanding the truth.
You will conduct the experiment with your tonearm clone Schroeder LT, and I will do it with Aki Schroeder.
We will shoot it on a camera mounted on a tripod and upload it to YouTube.

The technical expert, I hope he will not refuse such a favor, will be Carlo.
He will determine the possibilities of each option based on our videos.

But first, we will need to determine the conditions of the experiment.
The first condition is that the experiment should be simple.
And then we will collectively work out the remaining points.

I am ready to conduct such an experiment, despite the fact that I disassemble all the tonearmsand
the parts are lying around in the box.
I will assemble, adjust and conduct the experiment.

Now the answer is up to you and Carlo. The ball is in your court.

If such studies have already been conducted, please inform me.
I know nothing about it.

AG.
 
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