Used to make my own.
Buy 25' of 1/4' hollow braid rope, cut in half, take one half and fold in half, six inches down from the center insert the other piece of rope, pull it out after a foot has been fed through, pull the rest through to even up the ends and tape the "eye" in the middle shut. When you put it on the cable wrap one piece clockwise to cover 4' or so of the fiber, tape it at the end and the next one wrap counter clockwise and tape it, the next one wrap offset from the first, wrap clockwise so there is space between them all the way down and tape, the last one counter clockwise offset from the second with a space and tape all of them onto the fiber.
The biggest I pulled using this tool is a 144ct. and never broke it, but if you have a lot of tension the 1/4" rope may not work for the 864ct. but if you have all the duct lubed it may. the rope is stronger than you think.