Is there an economoical alternative to Ronstan/Harken/Lewmar sheave blocks?

Wing Mark said:
Which do you mean by 'A shaped'?
The system in the photo is very versatile, if you notice the adjustable nature of the blue lines.

If people want to centre the main for a light wind beat, it's not hard to add a temporary line to achieve that.
We accept this sort of thing for jibs, two sheets, barber haulers, sheet to a different track for a reach etc.
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The OP has posted at least three different mainsheet styles:
1) Original diagram - transom mounted, with attachments at two sides (typically to avoid a stern tiller), with rope going up from one side, over boom down to other side, back up to boom and down to cleat.
2) Original photo - coachroof mounted, with a “fixed” (but sometimes adjustable) bridle holding the lower mainsheet block
3) The GGR Rustler photo of two separate mainsheet systems, one from each side of the stern.

I my post #35 that you quoted, I was initially referring to No.3 (as being extra blocks, extra work and potentially extra danger to crew when crossing the cockpit as per photo). Then I suggested that No.1 would perhaps be a better option, of these three, for a cruising boat.

PS. I am happy with my coachroof track, keeping the mainsheet well clear of the cockpit, with sheet led back to winches by the helm via the “German mainsheet” system, but it is far from a low cost option.
 
coopec said:
When I started the thread off I was asking "Is there an economical alternative to Ronstan/Harken/Lewmar sheave blocks?" Thanks to a number of people commenting that query appears to have been answered.:p

Dunedin, maybe you should start up a new thread "Thoughts on mainsheet traveler V’s Double blocked mainsheet?"
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Why - you started in post #1 with diagrams and photos of two very different systems - so was just warning to design the system before selecting brand of blocks to avoid wasting money on wrong types :cool:
 
dunedin said:
Why - you started in post #1 with diagrams and photos of two very different systems - so was just warning to design the system before selecting brand of blocks to avoid wasting money on wrong types :cool:
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To demonstrate that I needed heavy sheaves to take high loads and 15mm sheets (The type that Harken/Lewmar/Ronstan charge several hundred dollars each). :rolleyes:
 
westernman said:
How about something like this:-

GM CLIMBING UIAA Certified 30kN Swing Cheek Micro Pulley Black General Purpose : Amazon.co.uk: Sports & Outdoors
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If it's claimed to be light it's likely to have some aloominum parts to it. Those in long term contact with other parts made from stainless steel will not last long but turn into white powder and then seize up. The same happens if you try to use climbing carabiners on boats. They don't like it because they are not designed for it.

Barton blocks are made from seawater compatible materials and are just fine for everyday non-high-end racing boats.
 
Hello Clive
I agree with much that has been said about main sheet systems. But firstly you can amke youyr own blocks. Just how good they turn out is another question though I think you can buy sheaves with ball or roller bearings. The cheeks made of stainless steel. Note here that in most systems the blocks closest to the becket (hard point) do not get as much movement as the blocks nearest the rope tail. So blocks don't have to be symetrical in the system.
Now the thread seems to have turned to discussion of main sheet systems. Dinghies have usually the capacity for a good vang system. This because of a large gap between the boom and the bottom of the mast (at keel) On a cruiser with cabin you have a much smaller space between cabin top and boom (relative to the length of the boom so from geometry vang is pretty ineffective. This means you must control the pull down of the boom (leach tension) with the main sheet. This is most easily done with a centre point main sheeting position to the deck.
However you can improve on that vastly by using a track (traveller) so that main sheet can pull down while boom is out from centre or can pull the main sheet base up to windward to get the boom central to the boat when beating. So on my little boat with large main sail when beating to windward the traveler is dragged to wind ward on each tack.
As said your first decision relates to sheeting the boom from the centre or end. Centre has sheet forward of the spray hood (if you use one) (this is not UK). this puts enormous bending loads on the boom. (it is the clew of the sail that needs to be pulled down and in) and more purchase power, or you could go end of boom (or near the end) sheeting which has a lot less load on the boom but needs much more rope and less purchase power.
I think for your boat I would look at end of boom sheeting. To a centre bottom attachment or if you cna fit it in a traveller track and car.
The so called "German" sheeting has the tackle at the end of the boom but 2 tails of the rope going forward along the boom down to the deck then back to winches on cabin top.
My advice is don't listen to those who say gentle men don't sail to windward. I reckon around here you will do a lot of beating to windward. Say coming home from Geraldton etc. You will want all the windward sailing performance you can get. So best main sheet arrangement for beating.
Sorry much of this has been said before. just reitterating ol'will
 
William
I most certainly respect your advice but at this stage I am leaving it to Taskers (riggers), Steve Hartley (sail maker) and the yacht designer (Bruce Roberts) as I don't understand the geometry anyway.

Maybe I will come to regret my decision however at this stage I just want to get the yacht in the water. ?

PS. I got a shock the other day when I checked the price of my two triple Spinlock XTS rope clutches: $480 each! Now the double sheave blocks............ :rolleyes:
 
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AngusMcDoon said:
If it's claimed to be light it's likely to have some aloominum parts to it. Those in long term contact with other parts made from stainless steel will not last long but turn into white powder and then seize up. The same happens if you try to use climbing carabiners on boats. They don't like it because they are not designed for it.

Barton blocks are made from seawater compatible materials and are just fine for everyday non-high-end racing boats.
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Good point.
 
PetiteFleur said:
It pays to look on ebay for blocks - I've bought excellent blocks & bits and pieces at good prices.
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I use eBay a lot but when it comes to sheave blocks that will take a rope over 12mm Ø there is .....nothing.:cry:

I am now trying Aliexpress and they do seem to have some good buys but so far the purchases are still in transit.
I've got a couple of sheaves 16mm Ø in transit but the specifications state the "Load 300kg" (see below).

BUT Ronstan Double sheave (Part Number: RF74202) is

Screenshot 2021-12-03 at 19-16-30 S75 Core Block,Double,Non-Swivel Head.png
That 1500kg wouldn't be breaking strain of the rope? NO:confused:. (Something doesn't add up):(


Screenshot 2021-12-03 at 18-53-34 11 48AU $ 38% OFF Stainless steel bearings V U type Groove P...pngScreenshot 2021-12-03 at 19-08-30 12 59AU $ 22% OFF LBER 2 Inch Roller Wheel Bearings U Groove...png
 
Carbon steel ball bearings will turn into a furball of rust at about the same rate that Honda BF2 outboards revert to iron ore.

Strewth cobber! Why faff around with this, contemplating Aliexpress Chinese made cheese metal junk? Barton blocks are completely fine for your boat, go up to 14mm, are good value for what you get, will do the job just fine, and you could have them in a box on your doormat next week.

You say you just want to get launched...
 
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AngusMcDoon said:
Carbon steel ball bearings will turn into a furball of rust at about the same rate that Honda BF2 outboards revert to iron ore.

Strewth cobber! Why faff around with this, contemplating Aliexpress Chinese made cheese metal junk? Barton blocks are completely fine for your boat, are good value for what you get, will do the job just fine, and you could have them in a box on your doormat next week?

You say you just want to get launched...
Click to expand...

I'm rapidly coming to the conclusion that Barton is the way to go.
I know I could very easily make up blocks myself if I could find sheaves that can take 15mm Ø (but I can't)

Thanks

PS Just had a look for Barton double sheave for 15mm rope Ø. No luck! (Time for bed : I'll have a look in the morning) (y)
 
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coopec said:
I use eBay a lot but when it comes to sheave blocks that will take a rope over 12mm Ø there is .....nothing.:cry:

I am now trying Aliexpress and they do seem to have some good buys but so far the purchases are still in transit.
I've got a couple of sheaves 16mm Ø in transit but the specifications state the "Load 300kg" (see below).

BUT Ronstan Double sheave (Part Number: RF74202) is

View attachment 126784
That 1500kg wouldn't be breaking strain of the rope? NO:confused:. (Something doesn't add up):(


View attachment 126782View attachment 126783
Click to expand...
48mm dia is too small for your rope size anyway.
 
There's a shortage of good used blocks on ebay right now!
Some used prices are stupidly high.
I've just ordered some of these:
Pulley Block 2 x 25mm + Nylon Sheave Bracket & Removable Pin Stainless Steel | eBay
Two small blocks for a fiver.
I will see how 'stainless they are.

There are some blocks on one of my boats which don't need to be great quality so I might swap them out and gain some good blocks for the yacht.
 
anoccasionalyachtsman said:
48mm dia is too small for your rope size anyway.
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I'm very much aware of the minimum size pulleys for wire ropes but I've often wondered about the size for for synthetic ropes. But now I know! Thanks. :D

So the pulleys I should be looking at would be 13mm (diameter of rope) X 12 = 156mm (6 inches)? :rolleyes:

But thinking about it it would depend on how much the pulley is used too? It is not as if I'm using it as a halyard, or jib sheet. What are the implications for eye splicing? For my use in controlling the mainsail, boom pulley diameter may not be critical? ?

Screenshot 2021-12-04 at 06-45-14 oilandgas-march09 pdf - Bridon-Ropes-synthetic-technical pdf.png
http://seaways.net.au/wp-content/uploads/2015/11/Bridon-Ropes-synthetic-technical.pdf
 
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Rummaging in the loft, ~I found some 1970s dinghy mainsheet blocks.
4 inch sheaves gave low friction with the ropes of the day and plastic-on-stainless plain bearings.
They take about 10mm rope but are very lightly made.
 
I think its been asked, or a question raised, and I don't recall reading an answer

But why is your mainsheet so big? Its going to be very difficult to coil neatly especially if you don't have hands like a gorilla.

15mm is quite hefty and you could downsize the mainsheet and then use smaller blocks. For maximum downsizing (or min rope diameter) why not change the mainsheet for dyneema. I recall all your cordage has been supplied - I'm sure you will find a use for the 15mm supplied. We have been using dyneema as a mainsheet since around 1989 or '90 - without issues. I put my money where my mouth is .... Our cat was supplied with 15mm as the mainsheet - we quickly changed it for 10mm dyneema.

Jonathan
 
AngusMcDoon said:
Carbon steel ball bearings will turn into a furball of rust at about the same rate that Honda BF2 outboards revert to iron ore.

Strewth cobber! Why faff around with this, contemplating Aliexpress Chinese made cheese metal junk? Barton blocks are completely fine for your boat, go up to 14mm, are good value for what you get, will do the job just fine, and you could have them in a box on your doormat next week.

You say you just want to get launched...
Click to expand...

Ronstan are happy to have some of their equipment made in China. You can buy the same equipment direct from the manufacturer, with the Ronstan logo. in my experience and that of Ronstan quality is excellent. I have had custom parts made in China, excellent quality and much cheaper than from Oz. Most of anchor chain for sale across Europe is made in China. Most anchors are now made in China

What did you buy that failed?

Jonathan
 
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