I find it easier to cut coils from the inside, out, when using a
Wind short coils - I use different diameter copper tubing as
mandrels, drill a hole in one end to thread an end of the wire
through to hold it in place as it’s winding, and chuck the other end
of the copper tube into the a cordless drill, and wind away.
Use the mandrel to place a short coil into a vise, and tighten, then
pull out the mandrel. I use strips of self-adhesive velcro- the
plush side, not the loop side- as liner for the jaws of the vise. It
will hold your coil tightly without marring, and also has enough give
to keep the tight ened vise from mishaping your jumprings.
Thread the blade in the jeweler’s saw backward- the teeth of the
blade will face the back of the saw. With one end of the blade
secured in the saw, thread the other end through the coil, secure
that end of the blade in the saw, and cut away, moving towards you as
you cut through the top of the coil. It’s a quick, easy way to cut a
lot of jumprings with basic tools.