How difficult is it to wind your own cutter head coils?

[Stevie342000]

Having been a relatively long time member of this group since 2009 I think, I have followed it's progress over the years, it appears we may have reached a tipping point with people now actually making replica heads and new fabrications for stereo cutter heads, overhead cutter carriages, motor control for overheads, computer control for Neumann or other associated electronics. Many are approaching an old technology with old methods and new technology to overcome the obstacles.

Most of the companies are long gone so there should be no issue with fabricating a replica, as long as you do not make look exactly the same I assume?

There are numerous Patents out there for the old equipment if you care to look or to check the reference section.

But what I am currently thinking is to fabricate a cutter head based on an old design or two which leads me to the main question:

How difficult is it?
What are the obstacles based on old design or a new one?
Where do you get sprung steel from?
Where do you get the laminations from?
What are the best materials?
What modern equivalent materials can be used?
How thin is the wire on the coil former?
How many turns do the heads that have been dissected have on them from Presto, Grampian, Universal, Audax, RCA etc?
What are the coil formers made from modern and old materials?

Personally I think it should not be too difficult to fabricate a new head using a mix of modern and old materials or methods based on an old or new design. I can see no reason why you could not 3D print the main cover parts of the cutter head if you had no access to a lathe in your front living room.

[studiorp]

Hi Stevie, depend if you want replicate a stereo or mono head as first point. If is difficult ? Yes, especially for a stereo head with design 45/45. There was a moment in which I had thought to build a stereo head like Ortofon design, with T bar, but after some technical considerations, I have prefered go on classic 45/45 design. I had already built a second or third prototype and too with much precision than other mine attempts, but there was a great problem, because the two speaker sound very well, and too the tube torque was vibrating, but with a vertical movement. Recently in a post here I have discovered that one channel must be inverted of polarity, otherwise there isn't lateral movement, if I am not in mistake...

[opcode66]

If you've been following my progress, then you know that one can absolutely make a cutterhead with a 3d printer. Most of my head is printed. All the moving parts for my transducers and torque tube are printed. I wind my own coils from flattened enameled wire I make myself.

I think you are asking good questions. But, they are a bit too general. There have been so many coil designs and configurations over the years. There is no standard for size, turns, gauge, glues, bobbin materials, dc resistance nor ac impedance. I can give you information at length about coils and how to make them. Probably easiest to do over the phone though. Feel free to call me for a chat. My number is listed on mumy web site.

Honestly, it might be easiest to just wait for RolandJays or myself to finish our respective cutterheads for sale. Unless you really want to build one. If so, be prepared for a lot of work. And, dont expect for those making or repairing cutterheads to tell you everything. It isnt in our interests to do so. After a lot of experimentation, trial and error, I've been able to figure out a ton of information that is not in any book or documentation. I'm more forthcoming with work than most. But, nonetheless, I've kept a number of discoveries to myself, naturally.

With respect to phase, watch my Bladerunner 1.B Part 1 video. I explain that to achieve a groove that appears in phase on disc given in phase information, the pistons actually move physically out of phase. This is achieved by reversing the connection for one of the transducers. Vertical dips and pinches are very apparent with out of phase signal. In pase signal only produces lateral motion.

[Stevie342000]

Agreed about do not share all the information what I was trying to achieve was to make it easier for newbies or those that wanted to make their own heads to be able to go to one place, rather than a series of threads. So that some of the basics could be covered by either buying ready made tweeters or to wind your own coils.

Somewhere where the main ideas on mono or stereo heads could be brought together. I've seen the Bladerunner video waiting patiently for the next one.

I get all the points on the various heads that are currently under development whether they are replicas or whether they are a new design concept. There are many ways to go about the manufacture of cutter heads new or old.

Building your own heads can not be that difficult if you have one which you can use as a reference or if you have the patent for a design you wish to replicate. Modern magnets will be a lot smaller and the problem that now seems to be rearing its head with Presto 1-C & 1-D heads is that their magnets are now becoming weak.

You can go to modern methods for printing main body parts on a 3D printer or you could cast them, if you know how to do it. Mono heads are easier to build than stereo heads but their is nothing really new in any design even if it is new, the materials we now have to hand may be better than what was around even 20 years never mind 70 plus years ago.

So how difficult is it to be a mono or stereo head? What are the obstacles? Why would you use flat aluminium or copper wire? Could you or would you use teflon, ceramic or metal (suitably insulated of course) as coil former? How to you remagnetise an old magnet? Is it just a case of attaching some new rare earth (neodymium) inside old head if there is space? Do you leave them there permanently or just for a short period to remagnetise the magnets?

My assumption is that if the magnetic field is not strong enough you run the chance of burning out the cutter coils because your cutting level will be low due to that decrease in strength. I think I have a good idea of how to go about building a head but that is not what I am trying to get at here, it is a bit more understanding on the problems encountered, a sort of glossary. Some of should probably be on the Wiki page rather than here, I don't know just trying to make it easier for newbies.

[opcode66]

Even with neodymium magnets, you still use a suitable drive level. They are not a magical solution to anything. In a Neumann head, everthing is so finely engineered that they could use a comparatively week electromagnetic/magnetic solution in comoarison to what can be achieved today. Im using neodymium and flat wire coils to increase the efficiency of my em/m system in order to compensate for the fact that my solution is neither as ellegant nor as finely engineered and fabricated as a Neumann.

With respect to having a head making it easier to design a head, not true. Not true at all. I have not and will not deconstruct my Neumann cutterhead. Additionally, I cut professionally, so I cant take my head out of comission for thr sake of curiosity. I cant have the downtime or the potential to damage it.

Flat enameled wire, why use it? Imagine trying to stack a bunch of pencils together. There are a lot of gaps. Each turn isn't really alligned as precisely as possible. This makes for a far less efficient em field. The resulting flux is not as focused, aligned or uniform. Now, imagine doing the same with cd cases. No gaps. Straight alignment. Uniform and coherent field. This is advantageous for many reasons.

Mono heads are painfully easy to design and make. Stereo, not so much....

Careful not to try to oversimplify things. We have separate theads because each concpet that comes together as a whole in a final cutterhead design could be discussed at great length. The ability to sum it all up in one thread is just not possible. Additionally, many trolls have already answered a lot of these questions elsewhere and would nti have the tome, energy or want to re-answer them here. If you really want an all in one thread, might I suggest that you curate the information already on this site. Maybe start a wiki or a blog and consolidate the existing info for others. Anything worth doing is difficult and takes work. We should all like to see some effort from you!

[Bahndahn]

So how difficult is it to be a mono or stereo head?

Building any detailed device is not overly difficult in any particular way - these projects amount to an accumulation of small tasks: measure, cut, glue, test, measure, test, cut, file-down, glue, test, etc. Patience is crucial, persistence will yield you a positive result. If you started building a cutter head and eventually gave up, you would still have gained knowledge.

What are the obstacles?

Your patience is likely your greatest obstacle.

Why would you use flat aluminium or copper wire?

Considering you mentioned 'flat' wire, you are talking about the coil wire, of which I have not seen anyone use aluminium. This may be due to its lower conductivity or something but I don't know much about that stuff yet. You can buy 'magnet wire' that is enamelled, it can be 'rolled' with a jewelers roller [mill] to increase the surface area; the flatness creates more surface that is parallel to the magnetic core.


Could you or would you use teflon, ceramic or metal (suitably insulated of course) as coil former?

If by 'coil former' you are referring to the sort of 'bobbin'-like unit that the coil is wrapped around, then yes, you could use those materials. You want it to be as light as possible in a moving coil situation. You could use lacquered paper.

How to you remagnetise an old magnet?

There is a machine that is capable of this I think, replacing the magnet is probably a better bet however remaining cognizant of the changes induced by a magnet of different strength would be necessary.

Is it just a case of attaching some new rare earth (neodymium) inside old head if there is space?

Worth a try!

Do you leave them there permanently or just for a short period to remagnetise the magnets?

If they fit, leave them! Optimally, you should remove the old magnets. If left in there, they would likely continue to change perhaps changing the performance of your head over time..[just a guess, I'm not sure].

[Stevie342000]

Thanks that was the answer I was looking for as they was pointed out they are general questions that only really needed a general answer. There was no need for the too often seen side dishes of offal and spleen.

As for my contributions there has been plenty of information on a number of patents, useful articles, websites and other assorted data by Presto, Fairchild, Universal and research papers from the BBC. If you're looking for blood you came to the wrong stone.

[opcode66]

What? Im not looking for anything.

[opcode66]

What? Im not looking for anything.

If you want a carpendeum of information, I was simply suggesting that you may start curating it and post it.

[Stevie342000]

If you have nothing positive to contribute then butt out, and I think you will find it is compendium. The object of this thread was to try to achieve just that for newbies, first hand from those that have something to contribute. A thread where those who had something positive to add could do just that if they so desired.

The concept was not for all the secrets to be shared but if people wish to then why not and for the obstacles to be pointed out, so people do not waste time and money if they wanted to make their own heads or to drive them in to the hands of the few that can make or repair them.

I do not know it all any more than you do or anyone else for that matter. Your last post suggests to me that you think you know it all, if that is so and you have nothing constructive to say then go bother some other thread or get on with your own projects or get some sleep.

I happen to admire your work my beef is your attitude, arrogance and assumption (inter-personal skills when engaging with others)that I am against you and pro (the name mentioned in PM rhymes) any one else but not for you (as per your pm). I thought it was too good to be true for you not to backlash. Shame really as that confirms to me that I would buy nothing from you, I had been at the point of reappraising you and buying a stereo head (you shot yourself in the foot).

On another note thanks for being the main driver behind me deciding to develop my own mono and stereo heads or to purchase them from anyone but you. Yes and the questions may have been a double edged sword but that is the way of it in audio and engineering or the world in general. Do you think that Voigt and Blumlein did not have conversations about their work and that they did not share knowledge when they met at the Institute of Electrical Engineers in London or one did not inspire themselves or others. It is well documented that they did talk and discuss issues as well as share in general, it was the way it was done then, you never knew when you could be working together or who was going to be the boss.

Do you actually believe in your own little world that you are discovering all the secrets and that they are new discoveries? Whilst I may understand someone who is making their living out of cutting discs that should not preclude them from sharing any knowledge, if they choose to share all or not is entirely up to them. But trying to wrap it up in anything other than an individuals own self interest is something else if they are not being completely transparent. It's like a half baked cake neither use nor ornament.

Again I understand that, its self interest but just in case you did not understand the object here, I may have had a degree of self interest in the pitfalls but the main objective was to make it simpler for newbies.

To put it perfectly plain and clearly, it's not that I do not respect your work, I just don't like you as an individual. That however does not preclude that if we actually met we might just rub along just fine, forums are not that conducive to all individuals getting along all of the time. As individuals we seem to rub each other up the wrong way, we just don't get along all the time. I can live with that but as I see it I did not warrant any personal attack on a perfectly set of valid questions that I asked.

Can we not just both agree to get on with the work at hand and have less of the side dishes of spleen and bile from either of us? Nor does it mean that I might change my mind and purchase an item from you in the future, we can all change our minds, it's allowed.

[opcode66]

Some do the work. Others talk.

[dimi751]

Hi Steve


I thought about this my self and decided that it will be too hard and time to wind coil myself
So I purchase these tweeters see links

Tweeters for cutter head

http://www.aliexpress.com/item/Car-audio-rodeo-tweeter-ld-high-pitch/1613479968.html

The amplifier I'm using is nad

http://www.hifiengine.com/manual_library/nad/302.shtml

The riaa electronics flozki one (super simple passive) (grazie flo)

http://www.lathetrolls.com/viewtopic.php?f=9&t=1185

Dimi

[45rpmdude]

Its very simple to wind coils.. im just having trouble.figureing out the guages.. None of the stores seem to carry the right guages.. so i had to go to a junk yard and get speaker. to canablaize the wire inside to make the head work..

[opcode66]

Not all coils are the same. Some are far more complex and difficult to achieve. This is the fifth layer I'm finishing. It is made by carefully aligned each turn under magnification using flat enameled wire I make myself.

It is very simple to wind inaccurate coils. Not very simple to wind accurate and highly efficient coils.