Electromagnet core? (1 Viewer)

[samtam]

I'm doing the 'make your own dc motor in class' prac, and I need an electromagnet, about 50x30mm -ish in cross-section. What should I use for the core? Or should I just make the armature smaller so I can use a smaller electromagnet?

 

[xiao1985]

you can use an iron nail if you like for the core...