Reversing Entropyvideo
I Created This Sailing Block. You Found a Secret Feature!
May 30, 2026 · 21 min · 32K views
Red rope threaded through metal pulley hanging from tree
What this video covers
The Entropy Block — a custom-designed, open-source sailing block made from 5083H11 aluminum — attracted orders for more than 500 units after its initial reveal, far exceeding the 10–20 the creator expected.▶ 1:23 The sheave, originally turned on a lathe, had to be injection-molded to meet demand.▶ 1:07 That process required building an aluminum injection mold from scrap, which was destroyed on its first automatic cycle when the ejector plate failed to retract; two further corrections were needed before the mold produced symmetric parts.▶ 4:37 A polymer engineer recommended a proprietary Delrin-based material used in deep-sea commercial fishing — self-lubricating, UV-resistant, and seawater-resistant — over nylon for the sheave.▶ 9:14 Load testing showed the line and shackle fail before the block.▶ 10:10 A collaborator called Big Z re-machined the aluminum body with larger line holes, chamfered radii, and a stepped sheave channel, adding "Entropy Block Open Src" and line grippers to the injection-molded sheave.▶ 12:55 The 5083H11 aluminum is argued to need no anodizing, supported by a side-by-side corrosion comparison with 7075 aluminum after five years.▶ 13:43 Freeze-and-ice testing showed the Entropy Block clears ice under load; a sand test showed a greased Entropy Block outperforms an ungreased roller-bearing block, which seized and required disassembly.▶ 16:26 A viewer discovered the block's shackle hole doubles as a friction ring for running a line in an emergency.▶ 10:58
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