.........Having thought this out, is it then possible to 'drill' out the centre using a cone cutter that I could make? The whipping on the ends of the rope could, maybe, hold the outer strands in place while this is being done....
Andy,
Never had experience in this context, but have worked with rope quite a bit, so a few thoughts:
The only way you would stand any chance of rotationally coring the end would be if you had fused it solid - otherwise I'm sure the fibres would just turn away from the pressure of any edge tool, rather than staying still long enough to be actually cut.
You
might manage to 'scoop' a little of the core out if you made a wire U tool to use with the likes of a Weller heat gun (as in heavy duty pistol-style soldering iron) - however you then run the risk of being left with a hollow fused cylinder which you would impede you compressing the tapered end.
You could try completely fusing the end and then thermoforming the taper; but you're likely to be left with a less-flexible transition which would be awkward to turn into the securing hole and might be a weak point.
All of these of course depend on what stock the rope is made from - polypropylene, polyamide, etc. - some melt, some just char.
I suspect the most practical way to tackle this is, as you outlined, to remove the whipping and then progressively trim the strands.
In terms of what to trim: without seeing the actual rope in question, and how it is laid, the issue seems to be that you wanted to keep the outer 'strands' in place. Typically the yarn and the strands are twisted in opposite directions - the yarn to form strands may be right-hand laid and the strands twisted together left-handed to form the rope - this balanced twisting (hawser laid) is to stop a rope un-twisting in service. Becuse of these twists, what is the outer yarn at the end may be well inside the rope an inch or two further back. So (from a detached perspective) I would suggest that trying to keep all the fibres that are on the outside surface may be a challenge not worth pursuing!
To achieve a taper like this, the first thing I would do is to confirm that the end is suitable - its not unknown for the end of a rope to be fused and then whipped, so you may have to go back up an inch or two to get workable material.
I would place a stop whipping on the body of the rope going back up the rope from where the taper is to start, to stop it unravelling beyond the head of the taper. I would then remove any current whipping and trim the rope just a little longer than the final taper length (the reason for this is that when you re-twist the trimmed strands they won't lie as tightly as when the rope was machine twisted, and may leave you short). I would then un-pick / comb out the strands and trim the taper (allowing for the diameter of any whipping that'll be re-applied)- either tapering it by eye, or push a fid up the centre and trim back to a cylinder.
The yarns can then be twisted to give a bit more structure - but as its such a short taper you may not be able to achieve that great a structure - and it may not be practical to achieve the same number of strands as in the original rope.
Keeping a permanent whipping on such a steeply tapered tail can be a challenge - the original whipping won't be much help, and (unlike normal whipping) you'll probably need to use a needle and take periodic stitches all the way through try to keep it in place. Depending on the final destination, you may even find that applying a few bands of thin-walled heatshrink, or something like Copydex, may be sufficient to hold the taper together until the pin is driven in.
Dave
