Magnetic Bed for 3D printer

Update 9/14/14
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Added a new version that does away with the tape and instead uses M3 screws of at least 8mm in length. SKP file also provided for customization.
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Installs the same way as the previous version as seen in photos of the previous version.
Although mainly created for use with http://www.thingiverse.com/thing:448686 here is hoping it may be useful for other applications to justify a separate Thing page.

Features
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Removable top portion secured by four magnets.
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Top plate removable, replaceable and held together by clips (Will look for a more elegant method to secure later).
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A "BuildTak" build surface makes applying "Blue" tape a thing of the past!

Important Note
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The aluminum plate was from the Thing-o-Matic heat plate. It is used to support an 8x8 LEXAN sheet found at the Home Depot (The LEXAN sheet is actually bigger but is cut to be 8x8). A Countersink was used to drill enough of a hole for the six screws to be