Outhaul pulley for windsurfing

Outhaul pulley for windsurfing.  Keep them on your sail in each clew position for fast rig and on water changes.  Cost is about 50 cents unlike commercial versions costing $30+

There are two designs to accomodate different pulley tube thicknesses.  Version A is for thicker wall cheaper galvanised tube and Version B is thinner wall stainless. Both have 16mm OD pulleys. You can adapt model to suit whatever tube you have.

You can get most supplies at Bunnings.   Stainless 16mm x 15mm tube (aka shower curtain rod) at Bunnings (I/N:  4821934) is $14 for 1.2m which is surprising cheaper than Aliexpress… should be good for at least 100 outhaul systems.   16mm Galvanised tube (I/N: 1130446) at Bunnings is $5.

Version A print uses the galv tube but has an internal seam you need to file smooth.  Note the galv tube also has much smaller ID of around 13.5mm vs the stainless tube of 15mm ID which is why the printed parts are different for A and B.  

Version B print uses the thinner wall stainless tube which will last much longer..

M8 Chicago bolts (which are actually M6, Bunnings I/N: 0035537). The Bunnings Chicago bolts are only zinc plated so likely to rust.  However, they are cheap and convenient.   I only include the Galv tube and Bunnings Chicago options as I had those parts at hand.

Superior build is using Stainless M6 barrel nuts (x 2) plus stainless 25-30mm long M6 grub screw (or cut a M6 bolt/threaded rod).  The barrel nuts I used have a shaft diameter of 7.85mm and a shaft length of 12mm (but shaft lengths between 10 and 15mm should work..see pic) Most bolt suppliers have barrel nuts, I got mine at WA Bolts https://wabolts.com.au  

Note you can interchange the Stainless barrel nuts or Bunnings Chicago bolts as they are the same dimensions.

(Version C and D are just A and B but have the barrel nuts recessed if you prefer that)

Rough cut the rings from the stainless tube slightly larger than the required 5mm length using hacksaw or cutting disc, then file to 5mm.   Drilling a 16mm hole about 4.5mm deep in a scrap of wood with a spade drill makes holding the rings easy whilst filing.  Obviously need to remove all burrs on OD and ID of these rings else will dig into print or rope.

I printed with PETG-CF but plain PETG or better probably fine.  PLA will be too brittle.   To increase the strength of the outer part (A2 or B2) you can print with gyroid infill and drill a 4mm hole through the outer perimeters in the thickest part.  Then use a syringe to inject epoxy to fill the void space. No chance of failure if you do this.

The rubber discs can either be printed from TPU or cut from a 1mm sheet of rubber or other fabric.  They are just to protect your sail…can probably get away without them if you lazy.

Note that the two parts 1 are polarised and mate together. When clipping part 2 into 1 it can be assembled 180 deg incorrectly so if the assembly doesn't lock together, flip part 2 on one side.  It's probably a good idea to use some blue loctite on the threads so they don't work loose over time.