Safire Associates, Unit 008, Solent Business Centre, 343 Millbrook road, Southampton, SO15 0HW
Copyright 2024 © All rights Reserved. Design by Safire
Harken 75 pulley block risers
We were asked to reverse engineer some old original split teak pulley block risers for these Harken 75 pulleys. Our customer wanted them made from an engineering grade plastic so they don’t split again. We advised using a Black Acetal plastic as Acetal is a good engineering grade plastic ideal for salt water use and black is best for UV stability.
Sleek looks!
Our new black Pulley block risers look nice among the other deck Gear!
These bolt right through the pulley and deck for full strength.
Pictured below is the original Teak pulley riser blocks, they were almost held together with the stainless steel strap clamps….
After creating the 3d shape in 3d cad and programming the machine, the Acetal plastic was jigged up and mounted to one of our CNC milling machines.
You can see here the part emerging from the swarf!
After machining the main shape, the blocks were set up on another milling machine to set the compound angles required to match the existing blocks as closely as possible.
The hole positions were critical as they had to realign up with the holes in the deck.
Here you can see an old block next to the new one being machined for reference.
The blocks were also handed so each one was a one off!
Shown above and below is the new Harken 75 pulley blocks set next to the old Teak pulley blocks.
We used Acetal as it offers high mechanical strength, stiffness and hardness as well as good toughness. Acetal has a high impact strength even in low temperatures.
Acetal has a good dimensional stability and low water absorption.
and we chose black as it is good for UV resistance!
E7563
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