Cross Staff Rope Making Machine

Cross Staff Rope Making Machine

This is a rope making machine of a type that was somewhat common in the 19th Century.

The gears can either be 24teeth and 6 pegs or 40 teeth and 10 pegs. Either way you get 1:4 ratio of twists.

You can see in this picture the cross arm need not be straight nor do the 2 hooks need to be exactly opposite. Nor do the three hooks need to be exactly spaced at 120° from each other, they could be but it’s not important.

What Is important is the spacing between the centers of the outer gears and the center of the main gear.

I have here drawn 24 to 6 , the smaller teeth of a 40 to 10 may run smoother.

I have not yet made this machine:

Most of the structure should be a softer wood like: Pine, Poplar, Bass, Cottonwood.

The main gear can be made of segments or made from a slab of the same softer wood, with teeth made from some very hard wood, like: White Oak, Live Oak, Lignum vitae.

main gear segment
main gear tooth

the main gear is drawn @ 1 1/2″ thick, the teeth are drawn 1″ thick.

I have drawn the small gears as 2 soft wood discs, 6 hard wood pegs, and a center 1″ hard wood shaft.

small gears

the center shafts of all the small gears need to have a hole bored through end to end, to accommodate the metal hook. OR make them 1″ too long and the hook can be made from a piece of pipe that only fits on the end of the center shafts.

hook made from pipe.

in use any wax or grease could be used to help it run smoothly, I prefer a 1:1 mix of mineral oil and bees wax. Any paste wax would work, or even bacon grease (very traditional)…

be well

Karl

2 responses to “Cross Staff Rope Making Machine”

  1. That looks like a fun experiment.
    Will you make that little round thing with 3 slots in it too, that you slide in front of the rope to keep the strands separated until you are ready to let them?

    Happy New Year
    Jonas

  2. To avoid excessive/unequal wear, the number of teeth of two gear should be coprime.
    Otherwise the same tooth from gear A will always come in contact with the same tooth of gear B.
    So instead of 24 and 6 use for example 23 and 6. It will not affect the working of the machine.
    So the two gear will come again in the initial configuration only after 23 turns of the small gear (and 6 turns of the great gear)

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