Angling for 90° - tangential pivot tonearms

It does, and there is.

If you extend the dashed friction force line back through the virtual pivot of the KL and apply that force along the constrained motion defined by the sliding mechanism, it will resolve itself into a lateral skating component whose magnitude will vary depending on where the headshell is on the record playing surface.

Ray K

I can just repeat myself: since the friction force is perpendicular to the direction of movement of the stylus, there just can not exist a lateral component, according to the rules of vector decomposition of forces.
 
Let me post the two videos again and an extra one.

YouTube Video #1 of KLaudio linear tonearm in Munich 2016

YouTube Video #2 of KLaudio linear tonearm in Munich 2016

YouTube Video #3 of KLaudio linear tonearm in Munich 2016

In the audio of Video#2, someone asks the designer "How does your anti-skating work?" just when he's about to explain it the clip ends. Too bad!

The videos shows when the arm is in the straightest position, stylus in middle groove, the assembly is furthest in the back and it travels forward on both inner and outer grooves. So, yes, there is a 'neutral' position as Ray suggested.

It seems those linear bearings are under a lot of mass, especially the whole 12" arm assembly, so how they overcome friction makes me curious about the quality of their bearings.
 
You are missing the fore/aft motion of the sliding base that moves the arm pivot with it. Your sketch describes the skating forces seen with articulated arms such as the Burne-Jones, Impossible, Van-Epps, etc. Again, you need to study the Klaudio YouTube video.

Ray K

I understand the pivot of Klaudio arm is not fixed. My drawing is based up alighiszem's drawing to explain the existence of skating force. I understand the drawing is simplified.
 
Back at it! Reading thru the last 40 or so pages to catch up. Seems no one has really tried to clone the Schroeder? Anyway, my attempt will finally continue now and I will try to post my efforts here. My first task is to read thru the patent a few times. Right now I believe I understand the basic operation, just don't think that the bearings I've selected will be adequate/or work the same as those Frank has chose. One question I should ask now to the forum is about damping. I believe that in the case of my arm, low mass for high compliance cart, that I will need more damping. Will the magnetic forces inherent in this design be sufficient to provide some of the damping I will need? I believe so but am not sure.
 
mcspack

I built a Schroeder LT clone a few years ago. (Not the twin arm Birch geometry arm) Careful attention of Frank's posts, the photos DD posted, and the patents will get you about 90% there. The remaining 10% can be derived from the rest, but will take a bit of thought. Frank mentions bearing pre-loading in the patents and posts. He's giving something away there and it will pay to read up on it. I used inexpensive ceramic hybrid bearings and, once set up correctly, they worked well. It's critical that the vertical axes of the horizontal movement bearings are accurate as possible.

I deliberately built a low mass arm intended for ADC or Shure high compliance cartridges because I thought that would be a tough test of the arm. It worked.

I'm not sure what damping you're asking about, but the magnetic guide, like most of the LT components, has more than one function including some damping.

Good luck with your arm.

DD - re the Klaudio: The parts! All those parts!
 
DD - re the Klaudio: The parts! All those parts!

Personally if I see a tonearm as Klaudio's, or similar kinds with so many parts, I would instinctively suspect it's performance. Yes. I may love air bearing tonearms too much. On my air bearing arm, there is basically just a head shell, but I found any changes in material and structure would change the sound.
 
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Thanks Doug,

Glad to know someone has ventured down this path before, especially with low mass-high compliance. Probably a bit off topic but damping is more of a concern with high compliance cuz they don't have much/any in the cantilever like a med-low comp cart would have. Some of the best sounding low mass arms had some type of damping. Servo, oil trough, magnetic. Seems this design already has a bit of damping built in, more or less, with the magnetic rail. I think I know how to venture down this build with hybrid ceramics. Seems that everyone might have to come up with their own pre-load strategy depending on how exactly they build their clone and which bearings they choose.
 
DD - re the Klaudio: The parts! All those parts!
Still simpler than this one! :D

Actually it does present more possibilities for non-parallel arms in its use of pivoting AND linear motion bearings for future inventions. I have some ideas in mind but at this point it's really half baked so I rather keep it to myself.

Personally if I see a tonearm as Klaudio's, or similar kinds with so many parts, I would instinctively suspect it's performance.

I don't blame you!
 
Here's a doodle for a pivoting arm on a rail that I've been dreaming of building.
Uses a single phase rail.
Devil is in the software, angular chip (fallback is linear encoder) measures the offset from zero to drive the rail (it's not linear), but the bobbin's tangential line does not follow the record's. So there is a variable change in the distance moved:rotation of pivot.
I'm banging on that atm.
 

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