User:Brian P. Josey/Notebook/2011/01/27

Wiring Electromagnet

Before I went on vacation, I created a frame for my electromagnet using Lego pieces and O-rings. With their small size and ease of use, the Lego pieces created a great frame, while the O-rings would keep the wires from slipping. To make the magnet work, I need to wire it today. Before I do, however, I measured the dimensions of my frame for reference:

• Length of wire piece: 39. 3 mm
• Thickness of wire piece: 7.9 mm
• Width of large gap: 9.5 mm
• Width of small gap: 1.3 mm
• Minimal distance between wires: 29.4 mm

I can use these measurements later when I model the magnet in FEMM.

After taking the measurements, I slowly began to wrap the cross pieces with the O-rings in wire. On the side with the large gap between the rings, I started with a 2.5 feet length of wire sticking out. This piece of wire is left over to connect to the current supply. Slowly, I wrapped the wire around the Lego piece, watching for any splits or twisting in the wire. Eventually, I wrapped the piece with 325 turns of wire. I then wrapped the connecting piece to work to the other side of the magnet. I then carefully wrapped around the second wire holder, taking care to ensure I was going the same direction around as in the first case. Eventually ending with only 25 turns of the wire on this half. I then measured the thickness of the wire both in length and width for modeling:

• Width with wire: 17.2 mm
• Length with wire: 45.8 mm
• Thickness of O-ring: 3 mm

All three of these measurements were made on the 325 turn side.