Documenting my hand-sewn eye process

SoftBankHawks said:
What percentage loss in strength does a good stitch give?
Yup, stitched ropes are useful, I use them too, infact I'm designing my trt system based on combo's of both.
I'm intrigued by stitching and want to learn more. My first 5 attempts felt hitnmiss to say the least.
Click to expand...
pretty sure properly stitched eyes test stronger than properly spliced eyes. but that's going by memory which can be questionable at times.
 
I know you didnt, fellow splicer ;-). There's a place for both types, but I really prefer a good ole hand splice!

Sent from my SM-G920R4 using Tapatalk
 
I have reading this thread with interest, and decided to join this forum. I do not climb in threes, but I have used ropes for climbing in mountains and securing on glasiers. And then I use ropes for some acrobatics and gymnastics use including chock cords. I have read several places concerning ropes for different use.

I did some test with low loads myselves using my own body weight and standing on body scales on the floor. In this way you can measure the force in test items to a fixed point above you.

It have been written here, that the end part of the eye would carry 30% of the load. I can confirm that in tests using steel carabins in the loop.

Then I have tried stitching with a sewing machine. The stiches from one side to the other will typically go about 60 degrees to the direction of the rope. I did try with a few stiches - 2, 4, 6, 10 and 12 stiches. In all cases it seems linear. 12 stiches holds 6 times more than 2 stiches. It will only be half the connecting threads that carries the load. When load is carried then one side of the stiches becommes about 90 degrees to the load and the other half about 15 degrees to the load.

I did also try some hand stitching. In this case almost all treads connecting the sides did carry the load. If you use the mantel only in the stiches, you can pass both ropes in every stich making the double amount of connecting threads on each pass of the needle.

I think hand sewing is good, but I do also have some concerns regarding the core part of the rope. With the stitches you connect very well to the mantel, but it might only be some friction to the core. So in case of few stiches with a larger diameter thread you may not connect to the core sufficiently.

It will also depend on how the core is made. The core for climbing rope have more twisted cordels. So I suppose that helps. For other kind of ropes you have straigt fibres in the core and then its hard for the sewing thread to connect. For double braided rope, the core will normally be braided with a low angle, so it can pass a pennetrading tread a long way before it locks.

The testing for this core problem may also be more difficult and different. I guess you need a lot of loads and unloads of the eye to see if the core starts to creep below the mantel. If it creeps in time, then later on it will only be the mantel strength taking the loads for a heavy fall.

By sewing in hand you may also be able to improve the friction to the core by wiggle the needle while you pass the core. But not to much, because it can break the thread when the rope carry a high load.

I don't say that hand sewing is no good. I would guess it is. But please observe these eyes and the core carefully over time.
 
There is zero core slippage in my hand-sewn eyes, some I've been climbing on (main climbing rope and split-tails) for 3 years, the stitched areas are rock hard, no movement, the eyes are outlasting the rope and cordage. My stitching does engage the core, the density of the stitching combined with the compressive force of the stitching creates an effective lock on the core no matter what the core construction is.
-AJ
 
Thanks for sharing your long-term experiences with your hand-stitched eyes, Moss. Really amazing results.

I also just wanted to chime in in order to say that I really like your new avatar photo. It's a great shot.

Tim
 
moss said:
There is zero core slippage in my hand-sewn eyes, some I've been climbing on (main climbing rope and split-tails) for 3 years, the stitched areas are rock hard, no movement, the eyes are outlasting the rope and cordage. My stitching does engage the core, the density of the stitching combined with the compressive force of the stitching creates an effective lock on the core no matter what the core construction is.
-AJ
Click to expand...

Thanks for your reply. I have no doubt of your rope eyes, Moss, and especially not after I made this test:
Test%20kernmantel-2.jpg

This test was done on a kernmantel polyester rope with a diameter of 1/3 inch.

When you start to pull these two part apart, then the mantel starts to compress the core on the 3 inches of overlapping. You can say, that four threads holds the mantel in one end up to a force of 4 x 2½ lb = 10 lb. Then this results in a friction between the mantel and the core in the 3 inches of the remaining 109 lb.

I did a test with 6 inches with friction and then I could not pull them apart with 183 lb. From a theoretical point of view the possible forces should be able to increase 11 times on the added 3 inches giving a total strength of 1318 lb.

So if the core starts to slip anywhere, then the mantel will immediately compensate by adding friction and force to the core. Only a small connection between mantel and core is needed at the rope side at the start of sewing of the eye. The rest could be connections between the mantels only.

Of cause the added breaking stress of the threads used to combine the rope sides for an eye shall be sufficient and have some margin. But this test will actually point out, that the way you make the stiches regarding the core should be quite uncritical. So I am convinced, that stitching an eye should by a safe way to make an eye.
 
Very intense, are you doing a 3 strand space, or 6 strand, between stitches? I seem to recall that you make 3 passes with your stitching awl? Great work nonetheless! I'm also curious of the awls needle size, if you don't mind.
Thanks in Advance.


Dave6390 in WI
 
I would feel safe using these eyes CBM.

The stitching awl I use is this:
https://www.awlforall.com/merchant2/awlproducts.html

This Awl and the competitor the Speedy Sewing Awl are sold all over the world. I have the #8 and the #5 needle to it. I have measured the diameter of the needles, at they are 2,0 mm and 1,6 mm. The slid dimensions for the thread at the needles are 0,85 mm and 0,65 mm.

Be aware, that you can only get sharp leather needles with these awls. So you need to grind the point of the needles so they don't cut the fibers of your rope.
 
I've got both types of awls and I prefer the open spool, it allows me to adjust the amount of tension by holding the spool with my thumb. They both work really well, though. Thanks for the needle sizes. I'm fixated on trying some E2E's, although I use the BDB &RopeRunner. The Rope Wrench is my next reliable device.


Dave6390 in WI
 
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