yep, DIY'ing is a lonely process! as is enjoying music for the most part. At least we have this great forum, 15 years ago we had none of it and DIY'ing is greatly benefiting. The choice of store bought arms in my price range is very limited so this is my only real option to get better sound than the rega 301 and acos I currently run. The rega just does not give me enough upper end presence and sounds overly/falsely 'resolved' as a consequence. The acos is actually better in that respect but still, neither gives up the micro details I'm looking for and I still think it's partly because the lack of lateral 'roll' movement of these gimbal arms do not allow for those bits of info in the grooves to be retrieved and that a unipivot does. But the basic unipivot does not provide for control of that lateral movement (unless you use a fluid well or magnet etc as this arm does) and so I hope this DIY arm will better the rega......will go on either a thorens125 or garrard/lenco.......
https://www.youtube.com/watch?v=o8ZdogYAlKk
I wish he would rotate the magnets circularly around that post to see what resistance there is if any. In terms of the arm application, we would not want any/much resistance in that direction I wouldn't think.......still trying to learn about magnets, poles, faces etc. A circular ring magnet has poles but a flat magnet can be magnetized on each face. What i don't know is if there is any poles/resistance in that situation. i.e. horizontal, rotational resistance caused by the magnet
here you can see rotation. doesn't seem to be much resistance.......also notice that the magnets are not perfectly parallel with each other, suggesting that one may need to rotate the two magnet combo until one finds the 'sweet spot' (if there is any) and the two magnets are level with one another
https://www.youtube.com/watch?v=gmx43Vx-luE
whoa....wonder what would happen if a ball magnet was recessed half way in the bottom of the arm and the string tree located perfectly tcentered over a ring magnet, as in this vid. would the control of the arm be any different better/worse than the two flat face magnetized magnets as in stock schroeder arm.......also notice the horizontal spin he is able to do. there appears to be some moderate resistance. wonder if this is enough to mess with the free flow of the cart along the record...and also if it is different than the horizontal resistance in the stock scrhoeder mag arrangement...
https://youtu.be/YZ1SaJ0--To?t=481
if the ball was epoxied in the bottom of arm, the string would only be needed to help carry the arm weight no? Is this the sarme thing happening in stock schroeder arrangement..i.e. is the string and mag sharing the weight of the arm.
I wish he would rotate the magnets circularly around that post to see what resistance there is if any. In terms of the arm application, we would not want any/much resistance in that direction I wouldn't think.......still trying to learn about magnets, poles, faces etc. A circular ring magnet has poles but a flat magnet can be magnetized on each face. What i don't know is if there is any poles/resistance in that situation. i.e. horizontal, rotational resistance caused by the magnet
here you can see rotation. doesn't seem to be much resistance.......also notice that the magnets are not perfectly parallel with each other, suggesting that one may need to rotate the two magnet combo until one finds the 'sweet spot' (if there is any) and the two magnets are level with one another
https://www.youtube.com/watch?v=gmx43Vx-luE
whoa....wonder what would happen if a ball magnet was recessed half way in the bottom of the arm and the string tree located perfectly tcentered over a ring magnet, as in this vid. would the control of the arm be any different better/worse than the two flat face magnetized magnets as in stock schroeder arm.......also notice the horizontal spin he is able to do. there appears to be some moderate resistance. wonder if this is enough to mess with the free flow of the cart along the record...and also if it is different than the horizontal resistance in the stock scrhoeder mag arrangement...
https://youtu.be/YZ1SaJ0--To?t=481
if the ball was epoxied in the bottom of arm, the string would only be needed to help carry the arm weight no? Is this the sarme thing happening in stock schroeder arrangement..i.e. is the string and mag sharing the weight of the arm.
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reciprocating processional hyperboloid. A magnet does not have poles. it has the inverse of counterspace, measured in volume!!..great explanation of magnetism based on tesla, steimetz, dollard understanding of electromagnetism. This must be why the tilt is seen on all the magnets, including the last ball in ring video. Would think we'd need to account for this in the arm no?
https://youtu.be/Aw1M3LbzGlY?t=366
more detail
https://www.youtube.com/watch?v=kVcRSAvnOuA
https://en.wikipedia.org/wiki/Hyperboloid
https://youtu.be/Aw1M3LbzGlY?t=366
more detail
https://www.youtube.com/watch?v=kVcRSAvnOuA
https://en.wikipedia.org/wiki/Hyperboloid
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Hi Plexi0
You wrote:
>if the ball was epoxied in the bottom of arm, the string would only be needed to help carry the arm weight no? Is this the sarme thing happening in stock schroeder arrangement..i.e. is the string and mag sharing the weight of the arm. <
That leads me to believe your understanding of the functioning principle of the Schröder arm bearing is wrong. The magnets attract each other and are kept at a distance by the string. In other words, the magnets do not carry the weight of the arm!
Since they do not touch each other, there is no "resistance"(or friction), other than the velocity dependent counterforce to movement in ANY direction(predominantly in the hoirozontal plane) generated through induction of eddy currents. And some veeeery small (thread)internal friction due to the fibres/molecules moving relative to each other.
I built this bearing utilizing ball magnets and still use different shapes for the surfaces on the SQ variant. That allows for the "stiffness" of the bearing to be changed according to what is desired in one plane vs. the other. Same for stable vs. neutral vs. unstable balance. All that info is to be found in the thread.
It is possible to use 2 ring magnets, but not one ring magnet and one ball or disc magnet.
In addition:
https://youtu.be/YZ1SaJ0--To?t=481
Good example of Earnshaws theorem at work. No matter what spherical magnet he picks - (I should have used the other one...") - yeah , right!... - the sphere will always make contact on one point inside the disc magnet. It is not sufficient to proclaim it won't, particularly when it always will... so forget about that one.
Lots of that stuff on youtube...
Cheers,
Frank
You wrote:
>if the ball was epoxied in the bottom of arm, the string would only be needed to help carry the arm weight no? Is this the sarme thing happening in stock schroeder arrangement..i.e. is the string and mag sharing the weight of the arm. <
That leads me to believe your understanding of the functioning principle of the Schröder arm bearing is wrong. The magnets attract each other and are kept at a distance by the string. In other words, the magnets do not carry the weight of the arm!
Since they do not touch each other, there is no "resistance"(or friction), other than the velocity dependent counterforce to movement in ANY direction(predominantly in the hoirozontal plane) generated through induction of eddy currents. And some veeeery small (thread)internal friction due to the fibres/molecules moving relative to each other.
I built this bearing utilizing ball magnets and still use different shapes for the surfaces on the SQ variant. That allows for the "stiffness" of the bearing to be changed according to what is desired in one plane vs. the other. Same for stable vs. neutral vs. unstable balance. All that info is to be found in the thread.
It is possible to use 2 ring magnets, but not one ring magnet and one ball or disc magnet.
In addition:
https://youtu.be/YZ1SaJ0--To?t=481
Good example of Earnshaws theorem at work. No matter what spherical magnet he picks - (I should have used the other one...") - yeah , right!... - the sphere will always make contact on one point inside the disc magnet. It is not sufficient to proclaim it won't, particularly when it always will... so forget about that one.
Lots of that stuff on youtube...
Cheers,
Frank
I was watching the curious man on youTube talking about magnets etc. If he hadn't said about Faraday I would have given up completely. OK what he says is fair enough. With enough thought it applies to other things. The fact that supposed electrons moving in a conductor can create this force is well beyond lucky. Also some metals ( etc ) will retain it is well beyond lucky. The fact coils can null to be less influenced ( hum ) and a ships compass made is what we usefully can know. I am sure Richard Feynman could have used less words and tell more truth. Well it had to be, I ask I find in my youTube link.
I looked for an the exact Feynman quote on problem solving ( Tuva lecture just before his death ) . As I didn't this is how I remember it.
HOW TO SOLVE A PROBLEM
First define the problem.
Do lots of thinking.
Solve the problem.
That's how you solve a problem.
https://www.youtube.com/watch?v=MO0r930Sn_8
BETTER
https://www.youtube.com/watch?v=xdZMXWmlp9g
I looked for an the exact Feynman quote on problem solving ( Tuva lecture just before his death ) . As I didn't this is how I remember it.
HOW TO SOLVE A PROBLEM
First define the problem.
Do lots of thinking.
Solve the problem.
That's how you solve a problem.
https://www.youtube.com/watch?v=MO0r930Sn_8
BETTER
https://www.youtube.com/watch?v=xdZMXWmlp9g
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I see two basic top sections. One looks like 5/16" (10/32) thick solid alu U channel that serves as both bottom and top plate. The thickest channel I could find is this, which is only 7/32 . Hope that is enough. All it's holding is the light weight of arm.
6061 T6 Aluminum Association Channel 6" x 210" x 3 1 4" x 12" Long 6" Channel | eBay
The other top section uses the massive, what appears to be 1 and 1/4 approx solid round brass. This seems much more than needed for strength. would imagine it sounds different than the U channel...
6061 T6 Aluminum Association Channel 6" x 210" x 3 1 4" x 12" Long 6" Channel | eBay
The other top section uses the massive, what appears to be 1 and 1/4 approx solid round brass. This seems much more than needed for strength. would imagine it sounds different than the U channel...
Where did he get his Phi^-3 from ? Circa 0.236068. More likely a quantity of e if a hyperboloid ( 2.718 ). The tenuous link is 3D space.
There is a stange proof for Pi that touches on this. e^(i.pi)= -1. It looks rather beautiful until one realises it is showing what I would call the trinary nature of the number i . That is powers of i rotate around 0 between -1 and 1 ( binary is 0,1 and this isn't really and 0 never comes into it like in real life ) . So the formula is just describing a 50/50 rotation. Much like Pi^0=1 is interesting. To have a solution to a transindental number is always nice. i is a very wonderful number. It seems from the answers it offers to be real. Below is a book I would like as the dilema is discussed. i^Phi is interesting. Not least if you come up with i^Phi plus 1,2,3,4...,, Now if our man said i^phi I would say perhaps.
If i^ phi is used it offers circa -0.825 and + 0.565 solutions with +/- variations as 1 is added ( a rotation ).
Enter [ (-1)^0.5 ] ^ 1.618. Many calculators will do it. Try 0.618,1,618,2,618 and more interestingly 3.618 etc. Phi is [ ( 5^0.5 ) +1 ]/2
DSP without Complex Numbers?
View image: Screenshot from 2015 11 01 15 16 38
this metal hollow tube that holds the string looks to be stainless steel. ? or aluminum? Wouldn't stainless interfere with magnet operation?
this metal hollow tube that holds the string looks to be stainless steel. ? or aluminum? Wouldn't stainless interfere with magnet operation?
thanks
http://s11.postimg.org/bsvq7h7oj/P1000056.jpg
getting started. Honduran mahog with rosewood lamination. Trying to get the arm light and delicate enough for 12" arm but if not will cut down to 10"......10mm at headshell end which is surely as small as it can be..... The weight now is just a tad heavier than carbon golf club shaft section. The two feel totally different with different tap tones for sure. I'll bet they do sound quite different......The real honduran mahog is quite light but still fairly stiff . The lamination further helps stiffen.......Am planning on making a rosewood headshll and gluing it on separately, or possible aluminum if my tools can finely fashion well enough. Will turn the end down once I source the end stub. I don't know how you all are making that endstub with two diameters unless you are milling it yourself? or are you using two pieces, one for the main section at string and another that holds counterweight?
http://s11.postimg.org/bsvq7h7oj/P1000056.jpg
An externally hosted image should be here but it was not working when we last tested it.
getting started. Honduran mahog with rosewood lamination. Trying to get the arm light and delicate enough for 12" arm but if not will cut down to 10"......10mm at headshell end which is surely as small as it can be..... The weight now is just a tad heavier than carbon golf club shaft section. The two feel totally different with different tap tones for sure. I'll bet they do sound quite different......The real honduran mahog is quite light but still fairly stiff . The lamination further helps stiffen.......Am planning on making a rosewood headshll and gluing it on separately, or possible aluminum if my tools can finely fashion well enough. Will turn the end down once I source the end stub. I don't know how you all are making that endstub with two diameters unless you are milling it yourself? or are you using two pieces, one for the main section at string and another that holds counterweight?
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i will have to use two pieces and epoxy one in the other...
Metal Supermarkets Everett | Buy Stainless, Aluminum, Hot and Cold Rolled
https://www.speedymetals.com/default.aspx
two great sites to source metal parts
Metal Supermarkets Everett | Buy Stainless, Aluminum, Hot and Cold Rolled
https://www.speedymetals.com/default.aspx
two great sites to source metal parts