Can somebody show me the pictures or a video how to wind magnet wire onto E20 transformer ferrite core without plastic bobbin?

 

It's much easier if you make one:

 

Yes I agree thank you. Please what material should I use for creating one?

 

show me the pictures or a video how to wind magnet wire onto E20 transformer ferrite core without plastic bobbin?

It is next to impossible and not a good idea. I have winding machines that wind on bobbins. They will not wind directly on a core. The cores will scratch off the insulation. Cores will conduct at high voltage.

 

Yes I agree thank you. Please what material should I use for creating one?

You can use any thin, stiff insulating material. I have used 1mm plastic sheet, varnished cardboard, SRBP, 1/32" plywood, etc.

 

Wind the wire onto some block (from wood, plastic, whatever), probably 6x6mm. Then pull out the coil from this block carefully. Use enamel to fix the coil surface.
Then put the coil on core and fix with enamel.

 

Another idea is to wind the coil on any material on top of extended lengths of Kapton tape.
When you are finished winding the coil, remove the coil from the form and wrap the Kapton tape over the turns of the coil.