Well-made ropes in diametres below 0.5 mm are rather scarce or
        unavailable at all commercially or only in a few sizes and
        colours. So
        serious  miniature shipmodeller has to resort to make his
        own.
        There are various descriptions of ropewalks in the modelling
        literature
        and on the Internet to be found. One can also inspect full-size
        preserved examples, for instance the one at the 
Chatham
          Historic
          Dockyard.
        
        
        
        Essentially, a ropewalk consists of a headstock with a planetary
        drive
        the gives the individual strands a twist against the 'lay' of
        the rope,
        while at the other end there is a tailstock drive that twist the
        rope
        together. A travelling bobbin (the denomination varies) ensures
        that
        the strands are separated and then fed together in a controlled
        fashion. However, Bernard Frölich (1999) suggested that,
        when one
        keeps the strands apart at the tailstock end and then twists
        them
        together, the rope will start forming from the middle of the
        walk,
        progressing towards the headstock and tailstock. It is this
        principle
        that was used for the miniature ropewalk.
        
        
        
        
        In my late fathers estate there was an optical bench with
        several
        'steadies'. The bed is triangular in cross-section and is, as
        the
        steadies, made from solid dark-brown bakelite. It dates probably
        to the
        1940s and was supplied by the well known German demonstration
        instrument company 
PHYWE.
        Not
        sure
        what my father would say about this
        new use, but after decades of slumbering in a dark corner of his
        study,
        it was calling for a new lease of life. It appeared to be a good
        base
        for a ropewalk and perhaps later also a serving machine, if I
        ever
        should need one.
        
        Apart from the gears that were mostly bought for the purpose,
        the
        ropewalk was constructed from pieces found in my scrap-box. The
        design
        evolved while I was assembling it, so some aspects are not as
        well
        thought-out as I would wish. For instance, for the headstock I
        should
        have purchased six pinions and installed them permanently in a
        hexagon.
        I was too mean and bought only four.
        
        
        
        The body of head- and tailstock is a small slab of 6 mm brass.
        The
        holes for the shafts were drilled and reamed to size. On the
        side that
        would have to take up the pull of the rope a 90° cone was
        sunk to
        create effectively half a cone bearing. This a better defined
        position
        than just a cylindrical bearing. The driving shaft in the
        headstock was
        left somewhat protruding to allow fixing at a later date a clamp
        for
        holding very thin wires for twisting them together. The hooks
        were bent
        from iron wire and hard-soldered into the shafts, as were the
        hooks in
        the driving plate of the tailstock. The driving shaft of the
        tailstock
        can be blocked by a thumbscrew that acts on a small brass pad,
        but the
        very thin ropes that I am making do not exert that much torque,
        so this
        may have been not necessary.
        
        The steadies of an optical bench are not meant to travel, they
        are just
        set by a thumb-screw that screws into a triangular groove of the
        bed.
        However, the tailstock of a ropewalk has to move to allow for
        the
        shortening of the strands and the rope while being twisted
        together. I
        added round gibs made from aluminium rod. Round because I was to
        lazy
        to reproduce the odd triangular shape of the grooves. The
        tailstock is
        eased by hand to allow for the shortening because the rather
        long stems
        of the steadies lead to canting and thence to breaking of the
        very
        delicate ropes.
        
        Depending on the direction of cranking, left- and right-handed
        rope
        with three or four strands can be made.
        
        
Reference
        F
RÖLICH, B. (1999): L'Art du
        modélisme.- 304
        p., Nice (Editions Ancre).