I will be using cylindrical magnets and shaping them.
My next problem is to fathom out what 'barrel shaped " looks like when filed out of a cylinder magnet
Thank you for still taking an interest in this thread Frank. I wish that I could afford to buy an arm from you..... I would do so in a heartbeat. Sadly diy is my only hope of ownership.
Hi deadhead,
Make sure you order several extra magnets. Neo material is very hard and prone to fracture. Excessive heat will surely partially or completely demagnetize neo magnets. Stick with N50 or N52 to get a strong size to strength ratio. Also, bare neo material will practically rust over night, that is why almost all neo magnets are nickel plated. Slow and steady will win this race. As mentioned, the dust from neo material is toxic so protect yourself. Post some pictures if possible. Good luck.
Make sure you order several extra magnets. Neo material is very hard and prone to fracture. Excessive heat will surely partially or completely demagnetize neo magnets. Stick with N50 or N52 to get a strong size to strength ratio. Also, bare neo material will practically rust over night, that is why almost all neo magnets are nickel plated. Slow and steady will win this race. As mentioned, the dust from neo material is toxic so protect yourself. Post some pictures if possible. Good luck.
Hello deadhead,
I wrote "barrel-segment" shaped, not barrel shaped. Imagine the upper magnets "face" to have two radii, the smaller at a right angle to the armwand, the longer one along the armwand. Again, smaller radius as seen from the front, large radius when looked at from the side.
No "sadly" to be connected with what you can build yourself. DIY-audio is just more fun than the professional side(which can be a lot of fun from time to time as well, but overall... Not to mention the pride of listening to what you've built, not "just" bought.
Cheers,
Frank
I wrote "barrel-segment" shaped, not barrel shaped. Imagine the upper magnets "face" to have two radii, the smaller at a right angle to the armwand, the longer one along the armwand. Again, smaller radius as seen from the front, large radius when looked at from the side.
No "sadly" to be connected with what you can build yourself. DIY-audio is just more fun than the professional side(which can be a lot of fun from time to time as well, but overall...
Not to mention the pride of listening to what you've built, not "just" bought.Cheers,
Frank
Hottattoo and Herr Schroeder... thank you both for you help and encouragement . Magnets , to practice on, will be ordered today.
A lot of the links and the photos in this thread are now dead links... it would be nice if some people could ,maybe, check their posts and update them.
Would also be really good if people who have made a Schroeder arm of their own and have not posted in this thread would post photos of their work. It is always interesting to see if any new ideas are out there.
All the best to all
Joe.
A lot of the links and the photos in this thread are now dead links... it would be nice if some people could ,maybe, check their posts and update them.
Would also be really good if people who have made a Schroeder arm of their own and have not posted in this thread would post photos of their work. It is always interesting to see if any new ideas are out there.
All the best to all
Joe.
Does this mean the center of bearing is slightly off center by using a weak magnet?
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Does this mean the center of bearing is slightly off center by using a weak magnet?[/QUOTE]
Nope, strength(or weakness) of the magnets is not the point here... it is the attachment point of the thread vs. the height to diameter ratio of the magnets in use that determines the behaviour of the bearing when the arm is moved out of equilibrum. For a ball the effective diameter is much smaller than the actual diameter.
And there is the difficulty of aligning the poles of a ball shaped magnet perfectly perpendicularly.
Best,
Frank
Nope, strength(or weakness) of the magnets is not the point here... it is the attachment point of the thread vs. the height to diameter ratio of the magnets in use that determines the behaviour of the bearing when the arm is moved out of equilibrum. For a ball the effective diameter is much smaller than the actual diameter.
And there is the difficulty of aligning the poles of a ball shaped magnet perfectly perpendicularly.
Best,
Frank
I have read all through this thread several times and yet I still cannot get this thing clear in my mind...Is the upper magnet drilled through in a Schroeder arm? Does a hole get drilled all the way through it and the knot reside somewhere near the bottom of the magnet?
Lots of the diy arms on this thread seem to find a way to fix the knot at the top of the magnet and so avoid drilling the magnet at all. That would make the pivot point of the string half way through the arm whereas the drilled magnet would have the pivot point at the bottom surface of the arm.
But what happens in a real Schroeder ?... drilled or not drilled? ( I am thinking of his later arms and not his early ones.)
Does anyone know please?.
Lots of the diy arms on this thread seem to find a way to fix the knot at the top of the magnet and so avoid drilling the magnet at all. That would make the pivot point of the string half way through the arm whereas the drilled magnet would have the pivot point at the bottom surface of the arm.
But what happens in a real Schroeder ?... drilled or not drilled? ( I am thinking of his later arms and not his early ones.)
Does anyone know please?.
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Thank you for that.. which of the newer Schroeder arms did you get to look at?
Hi,deadhead
Basically, the knot gets tied at about the center of gravity of the aluminum rear part of the arm. I would a thin drill (perhaps .75mm to 1mm) and drill completely through the aluminum and then flip it over and use the exit hole as your line up for the drill size for the magnet. However, I would use an endmill of the magnet diameter you choose so you get a flt bottom of the hole. I would also use a piece of low carbon steel about 2 to 3mm thick the same diameter of magnet you choose and drill a diameter slightly larger then the string you will use. You can now drill the steel disc about half way through with a 2 or 3mm drill so when you tie the knot it will stay inside the disc and let the magnet sit flat inside its hole below the disc. So, you put the string through the top of the aluminum arm piece and out through the bottom and pass the string through the disc, tie the knot ,pull the disc to the bottom of the magnet hole and install the magnet. Leave the string long and then cut it when you are sure everything is right. I hope you understand my non professional writing. I suck with computers or I would draw my idea for you. Good luck.
Basically, the knot gets tied at about the center of gravity of the aluminum rear part of the arm. I would a thin drill (perhaps .75mm to 1mm) and drill completely through the aluminum and then flip it over and use the exit hole as your line up for the drill size for the magnet. However, I would use an endmill of the magnet diameter you choose so you get a flt bottom of the hole. I would also use a piece of low carbon steel about 2 to 3mm thick the same diameter of magnet you choose and drill a diameter slightly larger then the string you will use. You can now drill the steel disc about half way through with a 2 or 3mm drill so when you tie the knot it will stay inside the disc and let the magnet sit flat inside its hole below the disc. So, you put the string through the top of the aluminum arm piece and out through the bottom and pass the string through the disc, tie the knot ,pull the disc to the bottom of the magnet hole and install the magnet. Leave the string long and then cut it when you are sure everything is right. I hope you understand my non professional writing. I suck with computers or I would draw my idea for you. Good luck.
That is a really comprehensive simple and lucid explanation ... thank you.
My only other question , for complete clarity is, is that the way Frank Schroeder does it?
I have some 10mm x 6mm magnets that might just fit in... after shaping and adding the pole pieces .. and leave the knot at the C of G of the arm wand. I will practice the shaping and see what size I end up with . Otherwise I can buy smaller ones. I have more or less decided to make the aluminium part of the arm 12mm thick.....I don't know what others have found to be the best size?
Frank doesn't say what size magnets he uses ( although they could easily be measured ) so I don't know if the magnets should be smaller diameter ..say 8mm or even 6mm. The 10mm ones that I have are ferociously strong.
I am gathering all the materials together to make the arm and have nearly finalised my design.
I will post this next question as a separate question so that it does not get lost..
Virtually all the clones that I have seen, and Franks arms , have the column that mounts the arm through the arm board as an extension of the column that holds the two main gallows plates apart. ( does that make sense ? )
I have a notion to make my mounting column as an extension straight down from the lower magnet so that the arm would mount exactly in line with its pivot point. Does that make sense? It seems to me that it would make setting up the arm that bit simpler to do.
Whats the collective wisdom on that idea?... ok or stupid?
I can think of one reason where it might be not the best thing to do.
Virtually all the clones that I have seen, and Franks arms , have the column that mounts the arm through the arm board as an extension of the column that holds the two main gallows plates apart. ( does that make sense ? )
I have a notion to make my mounting column as an extension straight down from the lower magnet so that the arm would mount exactly in line with its pivot point. Does that make sense? It seems to me that it would make setting up the arm that bit simpler to do.
Whats the collective wisdom on that idea?... ok or stupid?
I can think of one reason where it might be not the best thing to do.
With respect I do not think that that is the case.
I think that Frank has now, and over many years, refined the design of his arm so that the many many subtlties of the design make it the great arm that it is.
It just looks simple. Simple it is not I think.
Anyone can make an arm to do 95% of what any arm can be. It is achieving that last 5% that separates the great from the rest.
Just fitting two flat magnets and a bit of string to a tube of metal or carbon fibre and calling it a Schroeder clone is like trying to build a Rolex watch after looking at a photo of one. Lots of information will be missing.
Hi,deadhead
As a DIY person, you can't use Franks mfg. methods since he sells many arms and you are making 1 or 2 for yourself. I am sure he either has several jigs or some CNC contractor who makes the critical arm parts for him.
The secret to making this arm work properly is the near perfect alignment of the top and bottom magnets (and shape), string, and gallows. If making a guess, I would say the aluminum part of the arm where the magnets go is about 14 to 15mm in diameter and the magnets are 10mm diameter.
I have met Frank at several audio shows and he is a very nice guy who will answer most questions regarding this products but must keep certain aspects secret. Frank has been MOST generous to the DIY community with his time and information and is a real asset. I belong to 2 audio clubs in the N.Y.C. area and know 2 people who use Franks arm. I could very easily ask to measure every arm dimension and publish it, but I will not do so out of respect for Franks research, hard work, time, and money he invested. Besides,
DIY is supposed to fun and a challenge.
As a DIY person, you can't use Franks mfg. methods since he sells many arms and you are making 1 or 2 for yourself. I am sure he either has several jigs or some CNC contractor who makes the critical arm parts for him.
The secret to making this arm work properly is the near perfect alignment of the top and bottom magnets (and shape), string, and gallows. If making a guess, I would say the aluminum part of the arm where the magnets go is about 14 to 15mm in diameter and the magnets are 10mm diameter.
I have met Frank at several audio shows and he is a very nice guy who will answer most questions regarding this products but must keep certain aspects secret. Frank has been MOST generous to the DIY community with his time and information and is a real asset. I belong to 2 audio clubs in the N.Y.C. area and know 2 people who use Franks arm. I could very easily ask to measure every arm dimension and publish it, but I will not do so out of respect for Franks research, hard work, time, and money he invested. Besides,
DIY is supposed to fun and a challenge.
I never asked and don't want...I was asking what the DIY community chose for their proportions and why?
Frank has already been more than helpful.
