Fully Manufactured Coldfinger Geometry


I'm proud to show off the first generation coldfinger components. As you can see you can distinguish the previously manufactured parts (left two) from newly made parts by different oxidation layers on surface. The thermal performance of this is to be tested soon. The first test went fail last year due to an unexpected problem.

The original design of the first generation did not consider the discrepancy between thermal contraction coefficients of copper and stainless steel. The 0-80 screws were, therefore, put under a massive amount of stress when it was cooled down to sub-50K temperature since copper tap holes contracted more than the stainless steel screws. The silver plated surface of the screws couldn't prevent this thermally induced mechanical stress from cold-welding. Now the screws were cold-welded to the docking station geometry. All the other 2-56 screws, however, were unaffected due to its large size (and therefore, larger percentage tolerance of screw tap dimensions).

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