Hi Carlo, Hiten, yespsb, jotom750, fredex and last but not least DarPhyve. Thank you very much for the kind words and I apologize for lumping all of you together. (I am basically lazy)
There was a European manufacturer who showed some interest but that seems to have petered out.
Last year I designed and built five conventional pivoting tone arms with Baerwald geometry and a floating head shell. They are almost finished except for the electronic anti skating circuit board. As soon as I get my hands on a decent camera, I'll start a thread on it.
Sincerely,
Ralf
Ralf,
First, congratulations! I know it has been a long journal for you.
However, I still have different views about your project. You call your arm "A FLOATING HEAD SHELL FOR A SELF PROPELLED, TANGENTIALLY TRACKING TONE ARM".
1. "SELF PROPELLED". In fact, the force to drive the arm inwards is the skating force. There are no other forces except the skating force. If by your definition, ALL regular pivot arms ARE self-propelled because the skating force will drive the arm inwards. I don't see the significance of calling your arm self-propelled.
2. "A FLOATING HEAD SHELL". I don't see the need for a floating headshell at all. If you try to separate the headshell from the arm, a floating headshell can't do that because the only driving force is from the friction of the stylus and the groove. The arm won't move if the headshell is completely independent of the arm. A floating headshell does nothing but adds some unwanted vibrations.
Your anti-skating device is a very clever device. If I understand it correctly, it provides a constant force against the skating force. This device may be very effective for a tangentially tracking arm since the skating force for your arm is a constant force. However, all regular pivot arms have variable skating force. If your anti-skating device can alert the anti-skating force electronically to match the nonlinear staking force, it will be wonderful.
In any case, I know it is not easy to be granted a patent. Congratulations again!
Jim
First, congratulations! I know it has been a long journal for you.
However, I still have different views about your project. You call your arm "A FLOATING HEAD SHELL FOR A SELF PROPELLED, TANGENTIALLY TRACKING TONE ARM".
1. "SELF PROPELLED". In fact, the force to drive the arm inwards is the skating force. There are no other forces except the skating force. If by your definition, ALL regular pivot arms ARE self-propelled because the skating force will drive the arm inwards. I don't see the significance of calling your arm self-propelled.
2. "A FLOATING HEAD SHELL". I don't see the need for a floating headshell at all. If you try to separate the headshell from the arm, a floating headshell can't do that because the only driving force is from the friction of the stylus and the groove. The arm won't move if the headshell is completely independent of the arm. A floating headshell does nothing but adds some unwanted vibrations.
Your anti-skating device is a very clever device. If I understand it correctly, it provides a constant force against the skating force. This device may be very effective for a tangentially tracking arm since the skating force for your arm is a constant force. However, all regular pivot arms have variable skating force. If your anti-skating device can alert the anti-skating force electronically to match the nonlinear staking force, it will be wonderful.
In any case, I know it is not easy to be granted a patent. Congratulations again!
Jim
There is no skating force. Just think of it as a passive parallel tracker.
It is not the skating force that cause the stylus move from the outer groove towards the inner groove. This travel is caused by the forced path defined by the groove. (If the spiral were cut from the inner to the outer direction, the stylus were traveling outwards, but the same inward pointing skating force were arise on a traditional pivoting tomearm).
Straight Tracker's floating headshell decouples the cartridge (the floating part) form the skating force. The arm itself is driven by the skating force and only the skating force, and the floating headshell is driven only by the groove.
This is a skating force. Please see the diagram. As long as the line between the pivot and the stylus is not tangential to the groove, the blue line in my diagram, skating force exists.
What did you mean by decouples? Did you mean the headshell moves by itself without interference with the arm? The headshell will NOT even maintain its position without the arm. A small linear rail will NOT decouple the headshell and the arm.
Is the arm itself driven by the skating force? And is the floating headshell driven by the groove? How? I need to ask you a simple question. Where is the source of the force? The only force is the friction between the stylus and the groove. This is the only force to drive everything, the headshell, and the arm.
Hi super10018,
Hi Jim,
Thank you for the kind words.
There is a lot to answer in your post. Please give me a few days to comment. I'll prepare a CAD drawing to support my answer.
Ralf
That's an excellent way to explain it. The word "decouple" is fitting.
The stylus is tangential to the groove. After all, it's a servo arm and the pivot base is articulated, similar to a Birch style arm. If the narrow headshell rail is widened to be 4 inches, you would not even need a servo at all. Think of it as a parallel tracker that got squashed or narrowed to only one inch, therefore, we need something to extend the horizontal path. You are taking the visual of the arm too literally. Imagine if the headshell can create vertical or pistonic movement, you would not even need the arm at all as it would be a floating headshell gliding across the radius of 4 inches of groove area.
Or you can just ignore all of the above and wait till Ralf the patent holder to explain it for himself.
No. It is not a servo arm at all. There is no servo. I thought it was a servo arm before. The device which uses power is a pure anti-skating device. It does NOT drive the arm. There is no extra force to drive the arm at all. The arm is only driven by the friction of the stylus and the groove. So, as long as the line between the pivot and the stylus is not tangential to the groove, skating force exists.
No, the arm is driven only by the skating force. The skating force turns the arm clockwise. Without the servo, the arm would hit the headshell. The torque of the servo is CCW, and holds the floating headshell always in the center of the track.
Does it make any difference? You insist to use the word servo while I call it an anti-skating device. However, we don't disagree on its function.
You keep saying that the arm is driven only by the skating force. I had asked how. If you take the headshell off the arm, does the arm move? Of course not. The arm itself doesn't generate skating force even if you add an offset angle. So the skating force moves the arm inward through the stylus, the headshell, then the arm. If you try to decouple the headshell from the arm, the arm will NOT move.
Last edited:
Maybe I should let Ralf explain if my understanding is correct or not. Ralf uses the same device on regular pivot arms as anti-skating devices. Doesn't that tell you something?
I just want to add that servo is a form of correcting system. Ralf's arm does NOT use servo to correct tangency but it does use servo to correct the center location of the headshell in the cradle, as alighiszem suggested that otherwise the arm would hit the headshell. While it is not the conventional servo arm a la Goldmund T3, as Ralf's arm's tangential accuracy is already predetermined by the cam system, it relies on a motor and detecting circuit to do the task so it is still a servo system.
Well, servo means a driving system for me. Ralf's arm uses an electronic anti-skating device to counter the skating force. Let's assume such a device is used on regular pivot arms. By your definition, all these arms become servo-controlled arms. Does this sound right? I don't think so. In any case, we all know the function of such a device. You may call it a servo while I call it an anti-skating device. There is no fundamental difference.
Let's assume the arm hit the headshell. So what? A solid headshell can perfectly meet the tangential accuracy. The tangential accuracy is not determined by a small linear rail but by the cam system as you stated. The stylus or the headshell will be pulled arm towards the center of the record no matter the position of the headshell. For a solid headshell arm, the stylus pulls the arm towards the center. For a floating headshell arm, the stylus pulls the arm towards the center, too. Otherwise, the arm won't move at all. There is no such thing to decouple the headshell from the arm by adding a linear rail and keeping the headshell in the center of the linear rail. A small linear rail on a floating headshell is not the same as a regular linear arm. So skating does exist.