Mad Magnets

20 02 2009

I had no idea permanent magnets could be so strong… then I saw this insane magnet accident.

Polishing the Lids

20 02 2009

Taking a page from jewelry fabrication, I wet-sanded the face of the lids on 230 grit silicon carbide sandpaper on a glass table using a circular motion. This gives you a very flat surface.


Now they fit together tightly for welding:



Flower II

20 02 2009

Another nice projection of the superconducting coils:



20 02 2009

The parts from ProMetal just arrived. These parts feel heavy, dense, and strong. You really have to hold these in your hands to believe it. They hold water without leaking. Cost ~$30 each. img_3245img_3249

There is some texture, but overall these parts are highly conformal to the design. img_3264


This is very exciting. The first prototype core is within reach.

Next I will grind the touching surfaces of the lids and try to laser weld them together.


On the down side this material is magnetic:


I wonder if ProMetal can adjust the composition of the alloy. Stainless steel can be either magnetic or non magnetic depending on the alloy:

There are different types of stainless steels: when nickel is added, for instance, the austenite structure of iron is stabilized. This crystal structure makes such steels non-magnetic and less brittle at low temperatures.

Update: Looking at the ProMetal Materials Spec Sheet, it looks like they offer 316SS, which is non magnetic, although less strong than the 420SS. Bingo.

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