Low power input electric motor 67 miliwatts. How to improve it ?

[st12]

I managed to build a low consumption electric motor 67 milliwatts powered with a single small solar panel VIMUN SC 3012 - 2A (also inside an office calculator) exposed in artificial light.  It consists from a small solar panel, electronic circuit , air core and a neodymium sphere 19 mm diameter 27 g.
Probably you will wonder why ?
I am looking forward to make a Dc generator. A joule thief, converter, step up booster will not start using the tiny mentioned input.



Details : neodymium sphere 19 mm diameter - the key component Material NdFeB Shape, Sphere Diameter 19 mm Tolerance +/- 0,1 mm, Coating Chrome-plated (Ni-Cu-Ni-Cr), Manufacturing method sintered Magnetisation N38 Strength approx. 4,9 kg (approx. 48,1 N), Max. working temperature 80°C, Weight 27,2943 g, Curie temperature 310 °C, Residual magnetism Br 12200-12600 G, 1.22-1.26 T, Coercive field strength bHc 10.8-11.5 kOe, 860-915 kA/m - position of the poles up and down

There are a total of four electrical components. A small solar panel ( VIMUN SC-3012-2A, 29.44mm×11.6mm×1.1mm, 4 cells. The following specifications were listed, 2.0 Vos, 9.0 UAsc, 1.5 Vop, at 200Lux), a 470 uF 10 V electrolytic capacitor, a coil iron less with thin copper wire and a small circuit board with a black blob on it. Under this blob is the integrated circuit chip (HT111A1)

the electrical components ( excepting the coil are from a solar toy )

Thx
St

[Ian.M]

To improve motor efficiency you'd need a closed magnetic circuit with pole pieces shaped to fit the sphere and minimised core volume to reduce hysterisis losses (but with enough core area to avoid saturation), minimal air gap (maybe 3x the sphere diameter tolerance), and much better bearings - probably jewelled. 

[st12]

Hello Ian !
Thx for the answer
I wish to mention that, I already avoid the friction ( excepting the one with the air ) as much as possible + glass. The friction is present only at the contact with the glass and is minimal. I am looking in the direction of the capacitor and coil. What is strange is that  the motor is running with the poles orientated up and down like in the attached diagram (attached  in the first post ).  If I move the orientation of the poles, the sphere is vibrating (no rotational effect )

Thx St