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Where do I find replacement pulleys for jib halyard


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I have a Laser 28 - bought new halyards and discovered that my pulleys are cracked and in pretty awful condition.   Having a heck of a time finding a replacement source - anyone have a favorite supplier?
I found a pair of Ronstan plastic pulleys on Amazon that matched diameter but they are too thick to fit in the mast, machining them down doesn’t appear to be an option.  
2 5/16 outer diameter

 3/8 center hole

9/16 width

D1E39C03-E013-4948-BA77-0D34C5211231.jpeg

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On 4/19/2020 at 2:21 PM, RMac said:

Oyster Bay boat shop does the best fastest work

Thanks! 

36.00 each in black UV stable delrin - sorry, no bronze bushing; just add to the cost with no improvement in performance. Sintered bronze is not very durable and 20 years (and over a 1000 parts made custom) making a delrin only sheave with no failures or complaints and rolling. 

A polished axle pin is HUGE for making the sheave wheel spin freely. 

Bam Miller 

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The problem with off-the-shelf sheaves is that they are made to a size for a specific block, desk organizer or something assembled by that manufacturer.  When the spar builders made their mast, most of the time the sheaves had to fit in the space given; the size of the cut-out, thickness of reinforcing side plates, diameter and location of axle pin which really determines the outside diameter and thickness of the mast sheave. I would be surprised if selden sheaves fit a laser 28.

I have personally measured every sheave that came through my shop, and just looking at outside diameter, in 3" sheaves i find full fractional sizes sometimes, but often they are smaller. For example, yesterday I made 4 sheaves that were 1.8" outside diameter, .470" thick on a 5/16" axle pin. I'm pretty sure that a 2" x 1/2" sheave would not have worked properly. 

Something to consider when replacing your sheaves - when was the last time you had yours inspected? 

Bam Miller 

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On 4/22/2020 at 6:20 AM, bammiller said:

The problem with off-the-shelf sheaves is that they are made to a size for a specific block, desk organizer or something assembled by that manufacturer.  When the spar builders made their mast, most of the time the sheaves had to fit in the space given; the size of the cut-out, thickness of reinforcing side plates, diameter and location of axle pin which really determines the outside diameter and thickness of the mast sheave. I would be surprised if selden sheaves fit a laser 28.

I have personally measured every sheave that came through my shop, and just looking at outside diameter, in 3" sheaves i find full fractional sizes sometimes, but often they are smaller. For example, yesterday I made 4 sheaves that were 1.8" outside diameter, .470" thick on a 5/16" axle pin. I'm pretty sure that a 2" x 1/2" sheave would not have worked properly. 

Something to consider when replacing your sheaves - when was the last time you had yours inspected? 

Bam Miller 

Nowadays this kind of thing can easily be 3d printed. 100% infill, MD if you are really worried about strength you can have them printed with continuous stand carbon fiber or chopped fiber.

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On 4/22/2020 at 6:20 AM, bammiller said:

The problem with off-the-shelf sheaves is that they are made to a size for a specific block, desk organizer or something assembled by that manufacturer.  When the spar builders made their mast, most of the time the sheaves had to fit in the space given; the size of the cut-out, thickness of reinforcing side plates, diameter and location of axle pin which really determines the outside diameter and thickness of the mast sheave. I would be surprised if selden sheaves fit a laser 28.

I have personally measured every sheave that came through my shop, and just looking at outside diameter, in 3" sheaves i find full fractional sizes sometimes, but often they are smaller. For example, yesterday I made 4 sheaves that were 1.8" outside diameter, .470" thick on a 5/16" axle pin. I'm pretty sure that a 2" x 1/2" sheave would not have worked properly. 

Something to consider when replacing your sheaves - when was the last time you had yours inspected? 

Bam Miller 

This guy is the PRO.  Send him your old sheave....game over.  

 

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21 hours ago, Grrr... said:

Nowadays this kind of thing can easily be 3d printed. 100% infill, MD if you are really worried about strength you can have them printed with continuous stand carbon fiber or chopped fiber.

Not. 

The trouble with 3D printing is that you are limited by the interlayer bond strength. Especially on something like a sheave which requires tensile strength in the Z direction. Continuous strand carbon printers suffer from the same problem, and to the same extent (yes, I own a MarkForged). 

Now you could print them in metal, which has far fewer problems in this regard. Currently it would cost you about 10 - 100X what bammiller is quoting. But one from him - even if you found a stock replacement it will cost as much or more. 

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On 4/19/2020 at 7:01 PM, Slick470 said:

Another vote for zephyrworks. 

ZephyrWerks made exactly what I needed and had it delivered in 4 days - from Port Townsend, WA to South Carolina!   Fit perfectly.   Better than original. 

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Ed (Zephyrwerks) is a dear friend and a very skilled (and fast) machinist. He has made his living for many years making folding knives for some very serious clients. Watching him make sheaves is like watching a choreographed dance that's sped up a bit. Multiple machines and different stock all going at once.

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7 hours ago, Naldini said:

Right on, have been looking for masthead sheaves for a while. Zephyrwerks prices seem competitive.. Not sure what anyone else thinks but OPs sheaves don't look that bad?

this might be quite subjective, imho. but i've seen worse, for sure...

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