Haha 59 kg of wiring, maybe he is used to wind coils for CERN.
Previously I used a calculator here:
http://hyperphysics.phy-astr.gsu.edu/hba...enoid.html (it doesn't work for me right now but it usually works)
I put 20 mm as the length of the solenoid, 4000 for permeability (not sure about this one, it could be higher) and 100 turns of 0.3 mm wire which can hold maximum of 0.7 A and the magnetic flux density in the center of the coil was computed as
B = (mu_r*N*I)/L
where mu_r = k*mu_0
mu_0 - permeability of vacuum
k - relative permeability
mu_r - relative permeability of the core
N - number of turns of wire
I - current
L - length of the solenoid
With these parameters it looks like this:
mu_r = 4000*4*pi*10^-7 = 5.026544*10^-3
B = (5.026544*10^-3*100*0.7)/.02 = 17.593 T
So I was quite happy with that result (never mind it is past saturation). But the result was nowhere near that value when measured. It is probably because my core is actually not 20 mm long, but much longer and I put wire only on the 20 mm part of it. In the end it will most likely be good to use a short but wide core.
Now I will refer to the paper I shared in the previous post and use similar parameters.
I got a steel bar that is 50 mm wide cut into 100 mm long pieces and if I stack them to be 50 mm tall (which is used in the document I shared in the previous post as an example), the core is very short and wide. I put a piece of wire to show the direction of winding. According to the computations in the paper, this should give 1.2 T with only 48 turns and around 0.3 A of current for iron core. Note the iron core also is round with relative permeability 3,700, whereas I am showing rectangular steel core (rel. permeability 785). But the lengths are the same so with rel. permeability of steel it should need 3700/785 = 4.7 times more turns of wire, so 230 turns of wire.
