The VC shown on the video uses solvent activated precoated wire .
*If* it were diluted adhesive it would get (by capilarity) between the former and the cylinder winding die, making it imposible to separate later.
They are not showing a couple steps, like when they pass current through the coil to heat and cure it, plus evaporating solvent.
I make speakers (40 years now) and use honey viscosity Araldit, spread a little on the former, heat it a little with a heat gun (made a fixture so it points at the coil at theright distance and angle) , it becomes "watery" with not too much heat.
Repeat for the second layer , tape loose ends to the former (they are easy to glue later) , heat the coil again and wipe it "dry" with a piece of clean cotton cloth .
Set the former aside and wind another coil on a new one, I had a few made by a lathe man.
When I have, say, 10 or 12, put them in an aluminum tray inside a small electric oven the kind used to re-heat pizza or sandwiches on low heat and close the door.
And go work on something else.
One hour later I have my dozen strong and light voice coils, as good as or better than any store bought.
I also have for 32mm, my most used coils, a special 1 foot long variable diameter core, so I can wind 8 or 10 of them at once; then the entire core goes into the oven.
Depending on need, I use Aluminum, Kapton or Nomex.
If I get Epoxy between the former and the core, it's a mess.
The coil is destroyed and the core needs to be *very* carefully "shaven" to clean it.
Can't grind or sand it down because dimensions will vary.
Good luck.
*If* it were diluted adhesive it would get (by capilarity) between the former and the cylinder winding die, making it imposible to separate later.
They are not showing a couple steps, like when they pass current through the coil to heat and cure it, plus evaporating solvent.
I make speakers (40 years now) and use honey viscosity Araldit, spread a little on the former, heat it a little with a heat gun (made a fixture so it points at the coil at theright distance and angle) , it becomes "watery" with not too much heat.
Repeat for the second layer , tape loose ends to the former (they are easy to glue later) , heat the coil again and wipe it "dry" with a piece of clean cotton cloth .
Set the former aside and wind another coil on a new one, I had a few made by a lathe man.
When I have, say, 10 or 12, put them in an aluminum tray inside a small electric oven the kind used to re-heat pizza or sandwiches on low heat and close the door.
And go work on something else.
One hour later I have my dozen strong and light voice coils, as good as or better than any store bought.
I also have for 32mm, my most used coils, a special 1 foot long variable diameter core, so I can wind 8 or 10 of them at once; then the entire core goes into the oven.
Depending on need, I use Aluminum, Kapton or Nomex.
If I get Epoxy between the former and the core, it's a mess.
The coil is destroyed and the core needs to be *very* carefully "shaven" to clean it.
Can't grind or sand it down because dimensions will vary.
Good luck.
Most of the magnetizers I've used were capacitive discharge. A big bank of capacitors are charged up to a couple hundred volts and then a triac circuit zaps that through the charging coil. The coil is usually a big electromagnet, maybe 6 to 8" diameter with an iron core in the middle and shell around it, it is open at the top and the woofer magnet structure sits on top of it.
Interestingly the iron parts of the woofer structure should shield the magnet from magnetization but the field is strong enough to saturate through them.
David S.
Interestingly the iron parts of the woofer structure should shield the magnet from magnetization but the field is strong enough to saturate through them.
David S.
Maybe Here
Read this thread:
What glue for coiling voice coils? - All About Circuits Forum
Regards,
WHG
Read this thread:
What glue for coiling voice coils? - All About Circuits Forum
Regards,
WHG
Magnetizing? Easy.
Just submerge the ferrite magnet in a field of 200KA/cm .
"cm" means the centimeters of *air* needed to close the magnetic circuit.
My "small" magnetizer , up to 102mm magnets by 20mm thickness , is monophasic 220V and "eats" 22 Amperes, meaning 4400 Watts.
The "medium" one, for magnets up to 150mm diameter by 25mm thick, is double bridge rectified (6 diodes) , runs from 380V AC (around 480V DC) and needs from 52 to 56 Amperes; a circuit cuts power at 46A so all magnets are the same. It means it eats over 26000 Watts (I stop it at 22000 for consistency).
And now I need e bigger one, for 190mm to 220mm magnets.
Problem is that even if I make 50 speakers a month, I need the SAME magnetizer as a Factory making 100000.
In fact, I make guitar speakers similar to Celestions, and the "good" Eminences and Jensens ... and I need the exact same magnetizer power as them.
Now I want to make EV and JBL equivalent speakers ... the machine costs like a car !!!!
I would make a CD type one, but don't have the necessary monster capacitors.
Just submerge the ferrite magnet in a field of 200KA/cm .
"cm" means the centimeters of *air* needed to close the magnetic circuit.
My "small" magnetizer , up to 102mm magnets by 20mm thickness , is monophasic 220V and "eats" 22 Amperes, meaning 4400 Watts.
The "medium" one, for magnets up to 150mm diameter by 25mm thick, is double bridge rectified (6 diodes) , runs from 380V AC (around 480V DC) and needs from 52 to 56 Amperes; a circuit cuts power at 46A so all magnets are the same. It means it eats over 26000 Watts (I stop it at 22000 for consistency).
And now I need e bigger one, for 190mm to 220mm magnets.
Problem is that even if I make 50 speakers a month, I need the SAME magnetizer as a Factory making 100000.
In fact, I make guitar speakers similar to Celestions, and the "good" Eminences and Jensens ... and I need the exact same magnetizer power as them.
Now I want to make EV and JBL equivalent speakers ... the machine costs like a car !!!!
I would make a CD type one, but don't have the necessary monster capacitors.
That is sure a lot of power requirement which means it is not so practical for domestic attempts. I am sure my home power supply cannot deliver that much power but industrial 3 phase only can.
Anyway that was quite Informative to keep in mind for future projects
Thank you
I suggest you do the same as me when I started: I made friends with some guys who *did* have a speaker factory.
They saw I was not "competition" at all, but a funny "mad scientist + whiz kid" type guy and let me use their magnetizer for free.
That said, I never arrived there with empty hands, but always with some pizza or a beer six pack or a couple "longnecks" (good quality wine bottles) or something equivalent.
And didn't abuse either, yet once I arrived with a dozen speakers they didn't like it very much.
But it helped me experiment enough to decide whether it was worth building the machine or not.
They saw I was not "competition" at all, but a funny "mad scientist + whiz kid" type guy and let me use their magnetizer for free.
That said, I never arrived there with empty hands, but always with some pizza or a beer six pack or a couple "longnecks" (good quality wine bottles) or something equivalent.
And didn't abuse either, yet once I arrived with a dozen speakers they didn't like it very much.
But it helped me experiment enough to decide whether it was worth building the machine or not.
"mad scientist + whiz kid" -Yeah, That is the I have survived all this long. other wise even myself have no Idea why I am doing all this ,I see family members and friends staring at me with a wicked grin pointing to truth that dont you realize you have gone too far ?
science?
gone too far?
for you:
The Dictators Live! With Handsome Dick Manitoba - Science Gone Too Far! - YouTube
gone too far?
for you:
The Dictators Live! With Handsome Dick Manitoba - Science Gone Too Far! - YouTube
I had a cap discharge magnetizer at my last job we used to magnetize neo speakers. The caps where in a cabinet about the size of half of a refrigerator. The caps were several feet tall. One time they blew up. It was not pretty inside the cabinet. Similar to another poster, we had a water cooled coil. Iirc, the voltage ours was running at was 3kV. The wires to the coil would move every time you fired it.
As far as gauss level required, you'd want to know what the BH curve of the magnet material you're working with looks like, and then drive it into saturation. So the actual energy required depends on the design of the magnetic circuit (magnetizer coil + speaker magnet system + how they're positioned relative to each other).
We also magnetized after everything was glued together. Then it's much less likely you'll pick up loose ferromagnetic particles in the gap.
As far as gauss level required, you'd want to know what the BH curve of the magnet material you're working with looks like, and then drive it into saturation. So the actual energy required depends on the design of the magnetic circuit (magnetizer coil + speaker magnet system + how they're positioned relative to each other).
We also magnetized after everything was glued together. Then it's much less likely you'll pick up loose ferromagnetic particles in the gap.
I wonder If there is any chance to alter BH curve for individual magnets ,I believe all of them would be saturated and the remaining is what we will have as our speaker magnets.
I used to get my magnetized after fixing pole piece . otherwise with the basket it was not easy to place the magnet properly.
the person did not allow me to see how they do, he always said it is too dangerous and lack of space for 2 person. All I hear was a strong buzz and it was done.
It's standard 2 component industrial "slow" epoxy.
Mixed life, say, 30 minutes, hardening time: 8 to 16 hours unless you use an oven, which is recommended because it becomes more liquid and "wets the surfaces it touches.
As an example: if I let it harden at room temperature, everything is fine, but if I unwind a couple turms, the wire keeps its enamel.
But if I oven cure it, it's much harder to unwind and it becomes bare shiny copper wire, the epoxy strips the enamel.
Mixed life, say, 30 minutes, hardening time: 8 to 16 hours unless you use an oven, which is recommended because it becomes more liquid and "wets the surfaces it touches.
As an example: if I let it harden at room temperature, everything is fine, but if I unwind a couple turms, the wire keeps its enamel.
But if I oven cure it, it's much harder to unwind and it becomes bare shiny copper wire, the epoxy strips the enamel.
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