Interesting New Sheaveless Block

Take a look at this new sheaveless block by Ronstan.., extremely light. Only can handle line up to 3/16" or 5mm. Could be utile for some lightweight rigging stuff.
http://www.catsailor.com/store/pc/SHOCK-SHeaveless-blOCK-very-lightweight-392p34835.htm

interesting. For you engineering types out there, what is the easiest way to measure working loads on a line? For instance, a jib-sheet or rotator line?

Back on the imaginary boat build I see. Please keep us updated with pictures.

I'm freaking hilarious!

At least you are alive....was starting to wonder.

These have been discussed quite a bit on Sailing Anarchy.
Ferrules such as those from Antal and Schaefer make a lot more sense as they are stronger, ligther and if they fail the failsafe is still in the eye splice.
The Shockblock is cool but is limited to a very light load applications which there aren't to many of on our boats. And there is no failsafe if it breaks unlike a ferrule.

If you want the easiest way to test loads, spinlock makes a load cell for measuring road loads. https://www.spinlock.co.uk/en/load-analysis/zs-ropesense-2/10-tonne-wireless-load-cell
I've used it, nothing super fancy but easy to use. I'd love to try it on the F18 one of these days.

I think it could be a good alternative to small stainless rings like we use under the tramp and inside the beam, or anywhere else some line guidance it needed.

I'm still trying to get over THart unfriending me on Facebook. It has been a difficult time for me.

Oh, I probably started that. I don't think he's gotten over me unfriending him yet. You were probably just there at the wrong place, wrong time. Innocent casualty.

(why is beheading the act of removing a head but befriending is an act of friendship?).

Sure, I'll pick one of those up ... $4,500? I would rather have a set of sails.

Closer than you think if the bank dude wasn't such a pr*ck

I'm too fat for an F18 anyway...

Do they make a f19 for "plus sized skippers"?

These look kinda cool, but I'm trying to imagine an application for them on my boat.

I think the inexpensive rings underneath the tramp are lightly loaded and work just fine as they are.

Perhaps the cunningham blocks up by the tack? Jib sheeting purchase? Spin halyard (up top)? Traps?

Haven't had trouble with any of these areas yet.

I can see how they might be useful in some of the bunji routing systems for the spin sheet take up and trap lines...but these are more expensive than Harkan's 16mm blocks and I would much rather use the real block with a sheave and bearings.

The advantage to this thing, however, probably is with entanglement. If it's in a system that often has slack in it I can see how this would be less likely to mis-orient itself. Perhaps on something like the mast rotation limiter or something.

Hey Rick, any chance you're about to add the antel type rings to your shop? I'm about to order some other stuff of you and need a couple of small ones (no I don't want the shock blocks).

oh, wait. That $17 is for a pair of those. That's not too bad and would start to be an idea in bunji or other shallow angle line systems

Think pretty highly of yourself much ? Unfriending me because you can't support your argument with facts doesn't bother me in the least, just shows poor character.
Maybe you need to plan another addition to the garage mahal to make room for your swelled head.

Ding, I thought you unfriended me. Damn, NSA spiking sailing buddies now.

And to stay on topic, I'd guess these "blocks" are geared toward kite boarding, like their little plastic ones.

Argument? Nah..that never happened. I just got tired of the endless drivel of hateful political stuff in my newsfeed.

Scarecrow, what is antel type rings
Rick

The French solo racers started using these where possible a few years ago on shallow angle leads (barber haulers and the like) to replace blocks with moving parts that could fail. These are lighter too. There are a couple of different varieties now - Hall makes a version as do Schaefer and Holt. It's a polished aluminum ring.

What he said. Great for low angle or high load cascades.

oh, cr*p.... did you just inadvertently resurrect the "Drill" thread? Nooooooooo!!!!

Nah, I was trying to tell Todd that I still love him even though I unfriended him.

ditto... Me To! A rare point of agreement! grin!

All ya gotta do is take me out of your newsfeed, bonehead. A tech savvy guy like yourself is bound to know that. You must be sniffing to much t shirt ink and vinyl fumes. Schneider doesn't have that excuse.

I went the extra mile when you reposted ridiculous stuff we'd already agreed was false and hurtful. Are you noticing a trend? Reckon we all have poor character and swelled heads? There's a difference between busting your buddy's balls and stoking the coals of discord.

Todd.... Perhaps I am just old school. I don't do well with the Push technology that facebook provides... It demands that I opt out out of particular news feeds to have any fun factor with FB.. I did not find the entertainment value high enough to go to the trouble and manage you. So, whether it's your political rants or somebodies drivel about cupcakes and babies, or all of the marketing BS that comes through... it is a PIA to manage.

Obviously, people could manage what they post on their own.... That old social rule... No politics or religion at dinner would work for me in this context..

So, at the dinner table, you can't just get up and leave when the politics and religion piss you off... I would much rather pull the information that I want to read when I want it. I can go argue politics on political sites when I want.... and leave when I want.

Mark, You did the right thing. you don't like what I have to say , go away as far as Facebook goes.
Dubs, Extra mile, Please.Yep, I see a trend . The socialist sailors that I know don't want to hear my opinion, 'cause it chuffs 'em. As far as your concerned you won't recognize any truth that doesn't agree with your progressive view, which you constantly deny having ( "I'm not a liberal"). If you can't even stand for what you believe in and wear that badge ( rather I agree with it or not), I've got no use for you, so good riddance, twice. I've had the same view for decades, if you never bothered to find out, and it took Facebook to clue you in, well I guess you never knew me.
This is not the place for this . I was called out I answered. I'm done typing about it. Keep harping,troll away, as I know you will, but don't expect a response....Unless you're Ding.

Hey, Jeremy, look! See? I'm a socialist.

(inside joke for someone who knows better)

Oh man, here we go....the only reason I get chuffed at your opinion is because it is totally inflexible, un-researched, and you won't quit trying to ram it down everybody's throat. For instance; if you were to study the true meaning and history of socialism you would understand that not only are we not experiencing it but also that to be liberal is not to be socialist. I'm sorry we destroyed this thread...I won't bother with this topic anymore.

mmmmmm

interesting......


can some-one link me up with this.... drill thread

One more thread I will never go back to.

Holy cr*p! Are you telling me there is false and hurtful stuff on FB and/or the inner-net?

Dang, there goes my seawater engine I just bought from that nice russian dude...

I should probably go back and read that myself... They're re-opening some wells here in my region (they've been pumping for over 50 years with nary a blip on the public opinion screen) and it's got people out flipping over cars and rioting in the streets.

Where is that tin-foil hat I wear? Did I loan it to Timbo?

Way to turn a useful thread into a bunch of $#it guys.

Did you get plonked or quoned?

In a (perhaps vain) attempt to resurrect the thread, I think I found a good role.

Want to convert my trap setup to adjustable, and thinking these might be just the ticket instead of using the double block. Too much friction? is MWL of 380# enough?

Jeff,

Maybe you've been following my thread on that other beachcat site. I had the same idea, and ordered the parts. The official Nacra and C2 double blocks used in the adjustable setup are ~$55 EACH. The ronstan double block is a ~$25 part. There is a knock off of the Ronstan/Harken part but I don't trust knock off's in a safety critical application, when the name brand guys see failure.

So I went with the shock blocks at $16 a pair from a local supplier (sorry Rick I might return these don't want to double pay shipping). My intention is to splice them together to form a double block using dyneema. To be fair to Ronstan I don't think this is the intended purpose but others have done it with Antal rings. My concerns are the following:

1) MWL; in a 2:1 setup I'm 185lbs wet so you're looking at 370#'s of load on the block. Other have pointed out you may see 2-3g's of acceleration occasionally so you may apply up to 3x that number, 1110 lbs. That exceeds the breaking load of the shock block. However, it's an aluminum block so it won't just snap. It'll likely deform and since you are only applying high loads for temporary periods of time. Finally, one must remember Ronstan designed these for similar applications/load cases on kite boards.

2) Friction. I went with 3/16" (5mm) diameter line which is commonly used in adjustable trap setups. Somewhere I saw (Murrays?) the shock block ideal line diameter tops out at 1/8". Now that I've seen that I'm going to go down to 4mm (another reason to shop locally) line, which actually increases my line cost. Previously I spec'd Excel Pro which has a 1511$# tensile strength in 3/16" diameter, but a mere 695# tensile strength in the 5/32" diameter (4mm). Hence I'll switch to a dyneema cored line, FSE Dinghy Control Line which is a nice running line and has decent price/performance ratio. In 4mm this has a tensile strength of 1574#'s. I want the blocks to explode before the line does.

I'll post photos and reviews of the system when I'm done. I'm doing this right but trying to save money where it makes sense. Also want a reliable system for ocean racing so if the shock blocks don't work they'll get returned.

Friend of mine had the new Ronstan sheaveless on his kite, I was surprised to see how tiny they are, not sure if I would feel comfortable putting any serious load on them.
Since they are probably made in a mould there is a sharp edge right in the middle of the block, noticed some line chafing there already after just a few hours of use.

I have been using these cheap (RKO i think) blocks on my adjustable trap set up for years...

I had to replace one set after a few years because they can get side loaded up and deform. I now tape or whip them together so that can't happen

Adjustable traps seem to be too much to screw with to me. I just use the standard dog bone. If I want to trap low, I use the low hole. I want to be higher, I use the high hole.

Plus, the more parts you introduce to a system, doesn't matter what it is, the more parts there is to fail. You could probably do away with the block too. Just use a sailmaker's thimble there. Other parts of that part of the trapeze will probably wear out before the wear from the thimble becomes an issue.

This is all I use, clean and simple:


I don't shackle the block on any longer, I just use a Harken 504 (I think that's the number) and put it through the thimble when I make my trap lines.

I used to always make them from the top down. I'd make the splice that attaches to the mast first, then set my handles and do the eye at the bottom. Where the handle meets the thimble it creates a wear spot and I think the solution to that is to just tie a stopper knot, (probably just an overhand knot would be sufficient), in the dyneema for the handle to stop against and have the thimble with the block an inch or two below that knot. Should be wicked durable that way.

To deal with the handle chafing the line at the thimble, I push a short cut line through the trap line (including the eye-splice tail, bend it back, and whip the line like mad. Then I put a piece of shrink wrap over it so the handle jams on the line and doesn't reach the thimble. I do like the idea of these blocks in this application because chafe at the sheave can be a real problem with the take-up tail.

I've taken that dogbone to the teeth a few times, which is why I prefer that wire loop with the plastic insert. Even when the insert/spacer fails, the wire loop remains viable.

But your setup still looks sweet. What size is that trap line to the mast?

yup , everything is a trade off. I have had them fail.

I prefer the ability to pull myself up and away from a swell in the gulf ....

I don't use those "can't miss trapeze handles" anymore ...

I had the wire rust away (where it wasn't visible) and dump me

I'm looking at the Ronstan linked blocks #RF20284. Working load 550lbs. BL 1210 lbs. These 20mm blocks come regular and high load.

3mm. I think I'd like to go smaller, but I use that same size all over the boat and I usually buy it by the spool. A spool of 2mm would last me a lifetime just using it on trapeze parts.

The 2.5mm (7/64") Amsteel is fine for trap lines. Just be ready for it to have some initial stretch. My a-cat lines stretched about 4-6" before taking a final set.

Jake how many sails and how many times did you adjust before it locked into a range +/1 1/8 of stretch (ie Final stretch point)

It didn't take long. It was done stretching mostly after the first day. It was a good day with 12+ winds so I was on the wire most of the day. That evening I remember looking at it thinking "crap, that stretched a lot" and I had to resplice it.

how hard was it to re-splice once you tensioned the line?

Karl,
Why not just get rid of the small microblock (H224) below the handle and just run the line through the thimble. I do this and it works flawlessly. Clean and simple.

What is everybody else doing up top to prevent chafe, or are you just leaving it bare? You guys using 4 seperate pieces or 2 pieces doubled/Brummel on double hand boats?

This is what I do too an its where I'm adding Antel thimbles on the new set to cut down a little on friction compared to the normal rigging thimbles.




On my current wires I have 6 inches or so of lacing at the top which gaves me the ability to adjust the length (To allow for creep in the inital setup) and also provide this chafe guard. What a lot of people do is just thread the lines through 6 inches of normal sheaving that has been stripped from easewhere on the boat, other use some rubber hose.

With regards to minimising creep, leaving the line you have purchased in one long length do a splice at each end that will become the top end of the lines. but before you do so put an old block in the middle of line. Now tie the two spliced ends to a tree or post and connect your mainsheet block to the block you have floating in the middle and pull the whole thing towards another tree or post. Go back every half hour and make it a bit tighter. Once you're happy it is not getting any longer or the tree falls down cut it in the middle and splice on the other end. Assume you'll get another inch of creep in the final splice.

First, Jake thanks for the amsteel stretch notes I'll re-splice to accommodate. If you leave the bottom splice adjustable you can account for this in time

Karl, the dog bone works well and I think is a great option for skippers primarily buoy racing and single-handers. For a distance racing setup I like the adjustable setups. Gets my butt out of the waves, and lets me trap lower than a dog bone setup ordinarily allows as crew. Less critical for the helmsman but the crew ends up on that wire too.

I went with 4 separate lines. More difficult to manage for rigging but the splicing was easier. We have no covers at the top for chafe but am curious what others are doing. I might slip some on since I grabbed a bunch of scrap the other day.

Please elaborate, not sure what you mean here. Lacing?

My "wires" are deliberately 6" to short then I lash it to the shackle on the mast with some 2mm chord. Sorry boat lives at the club and I don't have any photos.

Got it. Thanks

Not hard at all. Amsteel is pretty easy to work with even after it's been stressed.

I cover the line with cover I strip from some Excel Racing Pro where it could chafe. It gets covered in the eye splice (at the hound) and down the mast a little where it could rub/catch the rigging.

Hi Catman,
Ronstan block you are looking for:
http://www.catsailor.com/store/pc/s...ltCnt=10&keyword=RF20284&submit=

I suggest using Rick's block posted above or the equivalent Harken. The Ronstan shock blocks are too small for this application, they are tiny! I went with a single Antal ferrul instead; 2 spliced together would be perfect but there isn't much room to splice.

The shock blocks look perfect for replacing small blocks that lead shockchord around the boat!

What was the inside diameter of the ferrul? Was thinking 15mm would be about right

14mm. Seems about right. We're going to try a 12.7mm this weekend, probably work OK, we'll see. The big downside is the stopper slams into the ferrul and adds friction to the setup. It still works fine, but maybe not for teams that adjust a lot (the pros adjust every time they tack). That is why we generally see double blocks and why I wanted to try 2 shock blocks tied together. I may still give that a go but it's a fair amount of splicing vs. 1 single ferrul.

with 3 weeks until the start of our summer season I've got to pull finger and finish making my new trap wires. The Capricorn 2 I sailed on a couple of times last season had this system standard (owner has since swapped it for fully adjustable) but I really liked it and will probably do similar on my new traps.

What I'm planning to do is splice both both the main trap wire and short lower length around the outside of a round ferral which will let the shock cord run free through the middle and then do an adjustable splice at the bottom end.

Tried that awhile back during a Worrell, with just a ring instead of the can't miss( seen 2 of those part). The problem I had was the slack line loop was easy to grab or snag on stuff by mistake. I took it off after one leg and went back to the standard adjustable set-up. YMV.

The reason I like it is I'm only 5'6" so I have short arms. Having short arms and trapping low with the normal system (which I currently have) means there isn't enough space between the handle (and block/ferral below it) and the tramp to fully retract the dogbone right up and tighten the wire. As a result the dogbone is left swinging in the wind meaning you have to stop what you're doing and watch it as you grab for it.

Hmm that's an interesting problem for shorter folks, my helm is 5' 4". Part of the reasons we're going to the adjustable setup so the handle can be placed at the right spot for her, and she can trap lower on the wire. Having it swinging around on the tramp is no good. We'll have to try it when we get the boat re-rigged.

-Sam

I build my traps from the deck up. So the lower line is set so the handle is exactly where my arm reaches when "semi sitting" on trap (as against fully laying out). The the main trap wire is adjusted in length to get the ring about 4" below the deck.

Got an e-blast from Goodall design and thought one of the items within was worth resurrecting this old thread. Seems they were either reading our forum or were thinking on the same lines. Their new "stock" adjustable trap will use a ferrule in place of the double-block. Looks like a fairly simple spring project to me.



Goodall design page link here.

That's pretty cool. Thanks for sharing that...I'm planning to revamp our trap lines soon and that looks pretty good.

Under load, the blue stopper will be pressed onto the ferrule. Will this not making the control line at least difficult if not impossible to adjust? You understand what I mean?

That's for the bungee to attach to.

I can see that...but, honestly, you are going to have a heck of time doing anything with that V-jam cleat with your weight pulling on it anyway. I usually have to pull my weight on the handle to do anything with the cleat...so that would free up the ferrule.

You can usually pull yourself up (ie pull the adjustment line towards you .... but to let yourself down requires you to "unload" the trapeze briefly to uncleat.

i see what you mean, defeats the purpose of being adjustable under load, but what if instead of passing through the ferrule the rope was spliced around it, and a shock cord passed though the centre and down onto the ring.

What's wrong with the Tornado-style adjustable trapeze?
Why fix what isn't broken?

I cannot say from personal experience, but weight, reliability, and cost have all been mentioned in previous discussions.

Just checked and Marstrom has them for 371KR=~$57USD each, not including shipping (link here).

I'm weighing my options.

OOOF

We have some new small stainless ones available. Will get a pick posted later.