Unveiling Bullseye Strops for low friction rings

[Breaking Waves]

Originally Posted by fxykty

Can compression failure occur because of a tight whipping at the base of the knot?

I don’t believe so. Whippings are an accepted commercial procedure and practically speaking do not appear to be a failure point.

Compression damage would seem to require a lot more compression loading than a tight whipping generates. I don’t know what pressure is required for damage, I’m sure it’s well established psi.

[Breaking Waves]

Originally Posted by Breaking Waves

I don’t know what pressure is required for damage, I’m sure it’s well established psi.

just looked it up - looks like about 14,500 psi is the potential damage starting pressure.

[fxykty]

Originally Posted by Breaking Waves

just looked it up - looks like about 14,500 psi is the potential damage starting pressure.

In real world terms how much is that? Something way beyond what a human could apply, even with hand tools (excluding hydraulic presses and such)?

[Breaking Waves]

Originally Posted by fxykty

In real world terms how much is that? Something way beyond what a human could apply, even with hand tools (excluding hydraulic presses and such)?

I would think so.

Just as a back of the envelope - if you put 50lbs on a turn of 1mm whipping thread (on 12mm line), you get round numbers 800 psi.

[Breaking Waves]

They are getting started on the breaking.

[Seaworthy Lass]

Originally Posted by Breaking Waves

They are getting started on the breaking.

Drum roll needed .

I am eagetly awaiting results.

[Breaking Waves]

just looking at the shackle version instructions.

I can see diy needing some extra detailed instructions/tricks/tips to get all the strands equalized, on both sides. On the diamond side am I right you don't/can't really tension it to get the strands even? So do you just do this 'by eye' and hope the diamond will self-equalize it when loaded?

If you wanted to make one of these longer, you could either make the noose side longer or add a brummel lock to the diamond side. Is there any advantage/disadvantage to having the diamond be right snug on the weave?

[Seaworthy Lass]

Originally Posted by Breaking Waves

just looking at the shackle version instructions.

I can see diy needing some extra detailed instructions/tricks/tips to get all the strands equalized, on both sides. On the diamond side am I right you don't/can't really tension it to get the strands even? So do you just do this 'by eye' and hope the diamond will self-equalize it when loaded?

No, not by unaided eye . I use the same technique that I use for all soft shackles with stoppers: after tying the constrictor knot (or applying tape) at the base of where the stopper needs to finish, I cut the working ends to be of equal length so that I can ensure the stopper is tensioned evenly before it is pre-tensioned using a winch.

I posted full instructions with tips for this when making a button stopper here here:

Originally Posted by Seaworthy Lass

.......
If one working end is a little longer, cut it so that the two lengths match.

Originally Posted by Seaworthy Lass

The advantage of having the working lengths the same length to start, is that you can clearly see if you have tightened both of them equally:

That thread also gives lots of other tips.

I have provided no general tips at all for making soft shackles when I wrote the Bullseye soft shackle instructions, so that is not the only one missing. I simply focussed on providing all the tips I could think of for the Bullseye weave portion itself.

This was my comment regarding this in the instructions:

Originally Posted by Seaworthy Lass

Instructions for this are complicated if they are written so that someone with zero experience of making soft shackles could make one. It would take hours to describe this procedure well incorporating all the tips and photographing each step. I have started a couple of times, but am finding the task too daunting, so the following instructions assume reasonable soft shackle making knowledge:

————-

Originally Posted by Breaking Waves

If you wanted to make one of these longer, you could either make the noose side longer or add a brummel lock to the diamond side. Is there any advantage/disadvantage to having the diamond be right snug on the weave?

I would suggest making the eye side longer and leaving the diamond as the lock on the weave. This is simply because I think good load distribution between the two legs is then easier to achieve. The more complexity introduced, the harder this is.

SWL

[Breaking Waves]

Originally Posted by Seaworthy Lass

after tying the constrictor knot (or applying tape) at the base of where the stopper needs to finish, I cut the working ends to be of equal length so that I can ensure the stopper is tensioned evenly before it is pre-tensioned using a winch.

The equal lengths I am having a little difficulty with is before this (and not part of normal soft shackle instructions), not from the end of the weave to the stopper, but rather from the Brummel thru the weave around the LFR to the point where the stopper starts.

I guess you are saying you do that without the ring in place, and that both strands (should) have exactly symmetrical deflections so they end up the same length - is that right? Since I have been making these with the ring in place, it was not initially obvious to me that both strands were the exact same length, and not really possible to tension/even up with the ring in place.

Bear with me, I'm just a stupid user trying to muddle my way thru unfamiliar instructions

To aid in making these without the ring in place, some step by step photos of how to twist the open strands to make the two loops might be helpful. I have the end-state photo, but (I think) as the strop is 'built without the ring' there are several small steps of loop twisting which would be helpful to document. eg small step by step how do I get from here:



to a finished system with the ring in place?

[Breaking Waves]

SWL - for you: Instructions for crossed bury's - Cruisers & Sailing Forums

[Seaworthy Lass]

Originally Posted by Breaking Waves

The equal lengths I am having a little difficulty with is before this (and not part of normal soft shackle instructions), not from the end of the weave to the stopper, but rather from the Brummel thru the weave around the LFR to the point where the stopper starts.

I guess you are saying you do that without the ring in place, and that both strands (should) have exactly symmetrical deflections so they end up the same length - is that right? Since I have been making these with the ring in place, it was not initially obvious to me that both strands were the exact same length, and not really possible to tension/even up with the ring in place.

Oh, you meant the bit from the Brummel lock to the stopper! Sorry, I completely misinterpreted!

This is very important and emphasised in post #1 of the Bullseye thread:

Originally Posted by Seaworthy Lass

To maximise strength the length of the lines in the weave (and for the soft shackle the entire distance from the apex of the noose to the base of the diamond stopper) need to be kept identical, so follow the instructions carefully to achieve this.

Instructions on how to do this are in the edit to post #43 (the post with full instructions) that was made on the 5th August 16:

Originally Posted by Seaworthy Lass

Edited to add:
To maximise strength, it is very important that the load is distributed evenly, ie the two portions of line between the apex of the noose and the start of the diamond stopper are exactly the same length.
To help make the two lines in the weave the same length, use the technique described for the Bullseye loop strop before you start:
Wind your dyneema snuggly in the Bullseye pattern around your ring, as shown in post #14 & 15 as if you were making a loop strop. Read the instructions there on how tight to make it. Mark with a texta where it needs to be locked to maintain this. Unravel and measure between the marks. Average the two measurements. This is the distance you want to leave between the Brummel lock and the diamond stopper.

After making up a few of these strops with Bullseye weaves, I went back a couple of weeks leter and added a few additional tips to both the loop and soft shackle versions. The edits were made in bold in both posts so it would stand out that they were a new addition.

I think you are somehow working on original instructions and may have missed all those extra tips in the loop instructions as well in post #14 (link in my signature). That would explain why you asked earlier how tight to make the weave. Is this correct?

——————

Originally Posted by Breaking Waves

To aid in making these without the ring in place, some step by step photos of how to twist the open strands to make the two loops might be helpful. I have the end-state photo, but (I think) as the strop is 'built without the ring' there are several small steps of loop twisting which would be helpful to document. eg small step by step how do I get from here:

Attachment 193377

to a finished system with the ring in place?

I would ignore my comment a few posts back about making them without the ring in place. It is far easier to have it in (as in the instructions), as that single twist you noted is needed to keep the line untwisted when the weave is complete and trying to get this right without the ring in place is tricky.

If the ring is later removed, I suggest putting a bit of tape on the intact weave it to hold it in place. If this hasn’t been done and you have unravelled the loop as in your photo, the only way to get it right again is just to pretend you are weaving it from scratch: start with where the buried end emerges on one side and create a loop making sure the line is untwisted in the loop, then follow the line around and at the other end create the second loop the same way, again making sure it is untwisted, and put the second loop behind the first, then put the ring in the gap in the loops without disturbing the arrangement. There is no easier way as far as I am aware.

SWL

This is how the weave should sit in the ring when looking side on. If you have unravelled the weave and are putting it back together, ensure when doing so that there are no twists anywhere in the final result:

[Breaking Waves]

^^ thanks much - I obviously did somehow miss some of your instructions. I've been working on my other samples, and temporarily put this one off. Will get back to it soonish now.

[Benz]

Originally Posted by Breaking Waves

They are getting started on the breaking.

Attachment 193021

Attachment 193020

Are you not afraid that the aluminum ring will distort early, being loaded by a steel pin for which it was not designed?

[Breaking Waves]

Originally Posted by Benz

Are you not afraid that the aluminum ring will distort early, being loaded by a steel pin for which it was not designed?

We picked a shackle which filled the hole and provided full support to the ring.

The lab’s experience is that this reduces ring distortion compared to using a thinner “puller line” which does not fill the hole.

[transmitterdan]

Originally Posted by Breaking Waves

We picked a shackle which filled the hole and provided full support to the ring.

The lab’s experience is that this reduces ring distortion compared to using a thinner “puller line” which does not fill the hole.

That doesn’t make sense to me. Any round pin inside a larger size ring hole will place a point load on the pin and the ring. At least until one or both deforms. The deformation may not be permanent if the two are similar in size. But deformation must happen if substantial load is to be resisted.

I doubt any small deformation affects the breaking strength of the loop under test. But if the ring yields and is permanently bent then all bets are off.

Why not use a somewhat oversized puller line? Surely that stresses the ring less that the point load of the shackle pin.