Author Topic: Tutorial: A Simple Device for Making Scale Rope  (Read 1719 times)

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Offline jamesbeat

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Tutorial: A Simple Device for Making Scale Rope
« on: September 23, 2011, 05:42:32 AM »
When I was a kid, I found a book in the school library called 'Boy's Own Paper'.
It was a compendium of a very old magazine for boys, and had some 'Popular Mechanics' style articles.

I read an article about making a simple machine to make high quality bowstrings, and I built one.
It worked pretty good, and I remembered it when I was thinking about small ropes for cannon.

A quick Google search showed me that there is a demand for such a device because people need scale ropes for model ships, and presumably, cannon.

People call these things 'ropewalks', although I understand that this more properly refers to the long narrow buildings in which full scale versions of this machine were used to make ropes in the old days.

You can buy or build a ropewalk, either from scratch or from a kit.
These things seem to be well made, and it would be nice to own one if you made a lot of rigging for model ships etc, but what about if you just want to make the occasional few feet of rope here and there for your model cannon?

Well, the plans in the Boy's Own Paper were for a version of this machine that's so simple, it's beautiful.
You don't need to bother with gears, drive belts, complex mechanisms, or even accurate measurements, and you almost certainly have everything you need to make one lying around at home, so it costs practically nothing to build one :D


I made the ropewalk I'm about to describe in less than ten minutes, using only a drill, a saw, a piece of wood, and some wire.
It will make rope every bit as good as a commercial model will.

With that lengthy and rather unnecessary preamble out of the way, let's get on with making our ropewalk:

Let me start by saying that I'm not going to give specific dimensions and measurements for this project, because that would be too constraining.
I'm sure most people will have suitable materials lying around at home, so I'll just show the principles.
Once you've read through the article and understand how it works, you can make your own mind up about what materials to use.
I'll mention what I used for mine, but only take it as a rough guide.

You need three relatively thin pieces of wood. I used an offcut of 1/2" x 3" board, which I cut up into three pieces.
I made one piece smaller than the other two.
I left the other pieces a bit longer so I have something to hold onto while using the ropewalk, but this isn't really necessary.

You also need some stiff wire. I happened to have some stainless steel stuff, but a wire coathanger or some brazing rod or similar would be perfectly suitable.

Clamp two pieces of wood together and draw three dots in a roughly equilateral triangle arrangement on the top. I spaced the dots about 1.5" apart.

Choose a drill bit a little wider than your wire, and drill where you marked the dots, drilling through both boards.
Unclamp the boards.
You should have two boards looking something like this:




Cut three lengths of wire about 3-4" long, and use pliers to bend a hook shape at one end of each.
I cheated here because my pieces of wire already had loops at the ends, so I just opened the loops slightly to make hooks.

Push the wire pieces through the holes in one piece of wood.




Leave about 1/2" of wire, and then make a 90 degree bend in each.

Measure (or just eyeball) the distance between the holes in the wood, and make another 90 degree bend in each piece of wire slightly smaller than this measurement.





The idea is that the wires can rotate freely without fouling on each other.

Pass the free ends of the three wires through the holes in the second piece of wood.



Trim and bend the remaining wire to keep everything together.



Now take your third piece of wood, and drill three larger holes in it:



That's it!
Grasp the larger piece of wood, and move the smaller one in a circular motion, and you'll see that this individually rotates each of the three hooks.

To make a rope, you'll need your new ropewalk, some thread or string, and a weight.
For the weight, just use anything that's heavy enough to keep the strings taut, and that can be tied onto the strings. I used an adjustable wrench.

To make rope:

Decide what you want to make the rope out of.
To get the hang of things, try ordinary white string.

For these photos, I used double strands of string on each hook. You can use as many or as few as you like within reason. It's probably easiest to start with one strand per hook for your first attempt.

Cut three lengths of string. About 5' long would be good for a practice piece.

Tie one string to each of the three hooks.
(in the photo, the strings are just looped over the hooks because I used double strands. If you use a single strand, you will need to knot them to the hooks)




Pass the other ends of the strings through the holes in the board, making sure that they are not twisted together at any point and tie the ends together and secure them to the weight.




Each string should pass straight from it's hook and through the hole in the board without touching or crossing the other strings, like the strings on a puppet.
 

In a standing position, stand on the board with one foot to prevent it turning.
Raise the ropewalk until the strings are taut.



Look at the strings, and note the direction in which the fibers are twisted.

Maintaining slight upward pressure to keep the strings taut, start turning the top plate of the ropewalk in the same direction as the twist of the individual strings.

You'll notice that the strings start getting a little shorter as they twist tighter.

Keep turning the top plate until the strings are so twisted that they almost begin to kink into little 'knots'.
If any knots form, unwind the strings a few turns and massage the knots out with your fingers.
With practice, you will learn to judge when to stop twisting.

Now for the moment of truth!

Gently take your foot off the bottom board. The board and weight will start spinning, and the strings will magically twist themselves together into a rope.


When the board/weight stops spinning, and just before it tries to start spinning in the opposite direction, grab hold of it to stop it moving.

you should end up with something like this:



All that remains is to cut the rope free and tie the ends to prevent them fraying.

If the rope is 'hairy', ie has a lot of small fibers sticking out, pass it through a flame a couple of times and they will burn away.
a yellow flame (candle, lighter etc) will leave soot on the rope. This can look quite good, but if you want to avoid it, use a blue gas or alcohol flame instead.

Rubbing the rope with beeswax will give a nice final finish.






Now that you've tried it with a single string per hook, you can start experimenting!

Try two or three strands per hook for a thicker rope, or three strands of cotton thread per hook for a thin but detailed rope.

Try using only two of the three hooks to make a twisted pair, then use three of these together to make a thicker rope.

Make three thin ropes from thread, then use those together to make a rope.

For longer ropes, get someone to act as an assistant, and go to the top of the stairs and dangle the threads down.

As I said above, the beauty of this design is it's simplicity, in particular the simplicity of the crank mechanism, which dispenses with the gears used in other designs.
This ropewalk could be easily redesigned with more than three hooks for making different rope designs.

I haven't tried, but I see no reason why you couldn't make a larger version for twisting ropes for a full size cannon, using period correct materials and thread counts.



If you look on youtube, you'll see several examples of a more sophisticated version of this machine that is turned on its side so it works horizontally.
Instead of a weight, these machines use a crank assembly and a sliding bobbin type thing.
Unless you want to go into full scale rope production, most of these improvements are window dressing, as they only improve ease of use rather than quality of the finished product.


I hope this helps a couple of people make their cannon look 'just right'.

If you try this yourself, please share your results, ideas, and any improvements you come up with :)
He reached out and stroked shiny barrel. "Manuel, once there was a man who held a political make-work job like so many here in this Directorate, shining brass cannon around a courthouse."

   "Why would courthouse have cannon?"

   "Never mind. He did this for years. It fed him and let him save a bit, but he was not getting ahead in the world. So one day he quit his job, drew out his savings, bought a brass cannon--and went into business for himself."

The Moon is a Harsh Mistress by Robert A. Heinlein

Offline Double D

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Re: Tutorial: A Simple Device for Making Scale Rope
« Reply #1 on: September 23, 2011, 06:02:55 AM »
Great tutorial, straight tot he stickies.!!

Offline KABAR2

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Re: Tutorial: A Simple Device for Making Scale Rope
« Reply #2 on: September 23, 2011, 06:33:42 AM »
You just brought me back to my days as a lad in the Boy Scouts where we learned to make our own rope!
I am in need of making some for my Reaper.....
Mr president I do not cling to either my gun or my Bible.... my gun is holstered on my side so I may carry my Bible and quote from it!

Sed tamen sal petrae LURO VOPO CAN UTRIET sulphuris; et sic facies tonituum et coruscationem si scias artficium

Offline jamesbeat

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Re: Tutorial: A Simple Device for Making Scale Rope
« Reply #3 on: September 23, 2011, 07:01:54 AM »

Thanks, glad you enjoyed it :)

It occurred to me that I should have put something in the final photo to show scale, so here's a picture with a dollar bill:



In the photo, you are looking at:
Regular white string, 3 single strands
Jute twine, 3 single strands (lower brown one)
Jute twine, 3 double strands (upper brown one)

Of course, these would be too thin for the majority of model cannon, but scaling up is easy, just use more strands per hook, or make a thicker rope out of three thinner ones.
He reached out and stroked shiny barrel. "Manuel, once there was a man who held a political make-work job like so many here in this Directorate, shining brass cannon around a courthouse."

   "Why would courthouse have cannon?"

   "Never mind. He did this for years. It fed him and let him save a bit, but he was not getting ahead in the world. So one day he quit his job, drew out his savings, bought a brass cannon--and went into business for himself."

The Moon is a Harsh Mistress by Robert A. Heinlein

Offline flagman1776

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Re: Tutorial: A Simple Device for Making Scale Rope
« Reply #4 on: September 23, 2011, 07:02:11 AM »
 :)

Offline jamesbeat

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Re: Tutorial: A Simple Device for Making Scale Rope
« Reply #5 on: September 23, 2011, 07:28:09 AM »
That's pretty cool :D

What count/combination of threads did they use on your rope?

Of course, that machine uses the more complicated mechanism, presumably a geared or friction drive mechanism.

There's really no need to make such a complex mechanism for a small machine for making scale model rope.
It's just as easy to shuffle the board around as it is to turn a hand crank, and the mechanism is far easier to make.
I wasn't exaggerating when I said that mine took less than ten minutes to build!

To be honest, the actual twisting of the threads is the easy part. It doesn't take very long to do at all, cutting and tying the threads is the most time consuming part.
It baffles me that people bother to make the geared devices for small scale work.

On a larger scale of course, a geared mechanism would be easier to use.
He reached out and stroked shiny barrel. "Manuel, once there was a man who held a political make-work job like so many here in this Directorate, shining brass cannon around a courthouse."

   "Why would courthouse have cannon?"

   "Never mind. He did this for years. It fed him and let him save a bit, but he was not getting ahead in the world. So one day he quit his job, drew out his savings, bought a brass cannon--and went into business for himself."

The Moon is a Harsh Mistress by Robert A. Heinlein

Offline flagman1776

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Re: Tutorial: A Simple Device for Making Scale Rope
« Reply #6 on: September 23, 2011, 08:17:00 AM »
 :)

Offline jamesbeat

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Re: Tutorial: A Simple Device for Making Scale Rope
« Reply #7 on: September 23, 2011, 08:32:07 AM »
Here's a photo of a thicker rope, made by using three thinner ropes twisted together.
The thinner ropes used to make this rope were 3 double strands of just twine each, which is the same as the second thickest rope in the photo.



This rope is about 5/16" thick, and is about the upper limit for my machine because the hooks are too small to hold thicker strands.
This would be easily rectified by building a machine with slightly larger hooks, and also making the holes in the bottom board a little larger.
However, once you start making rope this big, you are getting into the realm of rope that can be bought from a hardware store.
If you need rope that big, you might as well just buy some, unless you're trying to make a specific type of rope that's not commercially available, in which case just make a slightly bigger machine.

He reached out and stroked shiny barrel. "Manuel, once there was a man who held a political make-work job like so many here in this Directorate, shining brass cannon around a courthouse."

   "Why would courthouse have cannon?"

   "Never mind. He did this for years. It fed him and let him save a bit, but he was not getting ahead in the world. So one day he quit his job, drew out his savings, bought a brass cannon--and went into business for himself."

The Moon is a Harsh Mistress by Robert A. Heinlein

Offline jamesbeat

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Re: Tutorial: A Simple Device for Making Scale Rope
« Reply #8 on: September 23, 2011, 08:47:24 AM »
The block that my daughter was working was used to press the strands together. 


Not quite, the block is actually to keep the strands separated, not to press them together.
It's the analog of the board with the three holes in my design, it stops the threads getting tangled and keeps them from twisting together too soon.
When the threads are sufficiently twisted to make a tight rope, the block is slid forward, allowing the rope to twist itself together.

In my design, the board with the three holes does a similar job. You stand on it to stop it moving, and this keeps the strands from twisting together until they are wound tight enough.
When they are wound up nice and tight, you take your foot off the board and allow the rope to twist itself together.
This could also be done by sliding the board up the rope, but in practice that would be too unwieldy for one person to do.

The fact that my design is vertical rather than horizontal means that it is possible to lay up the rope this way.
In a horizontal design this would not work, and you would need to use the block system instead, just like the method your daughter is using in the photos.

The fact that my ropewalk is for making small scale model ropes rather than the real thing means that a vertical arrangement becomes practical, and thus the design can be greatly simplified.

I'd just like to stress that when I say 'my design', I mean the design shown above. I didn't actually design it myself. Credit for that goes to the (probably long since passed) author of the article I read all those years ago.
The only credit I deserve is for remembering how to make the thing from an article I read around 20 years ago :D
He reached out and stroked shiny barrel. "Manuel, once there was a man who held a political make-work job like so many here in this Directorate, shining brass cannon around a courthouse."

   "Why would courthouse have cannon?"

   "Never mind. He did this for years. It fed him and let him save a bit, but he was not getting ahead in the world. So one day he quit his job, drew out his savings, bought a brass cannon--and went into business for himself."

The Moon is a Harsh Mistress by Robert A. Heinlein

Offline jamesbeat

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Re: Tutorial: A Simple Device for Making Scale Rope
« Reply #9 on: September 23, 2011, 09:50:04 AM »
Click the link for a youtube video of a similar design.
It's a rather unwieldy horizontal arrangement, but it shows the general principal better than I can explain in words:

http://www.youtube.com/watch?v=4myZ8rajxPc&feature=related
He reached out and stroked shiny barrel. "Manuel, once there was a man who held a political make-work job like so many here in this Directorate, shining brass cannon around a courthouse."

   "Why would courthouse have cannon?"

   "Never mind. He did this for years. It fed him and let him save a bit, but he was not getting ahead in the world. So one day he quit his job, drew out his savings, bought a brass cannon--and went into business for himself."

The Moon is a Harsh Mistress by Robert A. Heinlein

Offline flagman1776

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Re: Tutorial: A Simple Device for Making Scale Rope
« Reply #10 on: September 23, 2011, 11:00:55 AM »
 :-\

Offline GGaskill

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Re: Tutorial: A Simple Device for Making Scale Rope
« Reply #11 on: September 24, 2011, 08:23:48 PM »
Don't forget to add this to the appropriate sticky.
GG
“If you're not a liberal at 20, you have no heart; if you're not a conservative at 40, you have no brain.”
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Offline Double D

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Re: Tutorial: A Simple Device for Making Scale Rope
« Reply #12 on: September 25, 2011, 04:52:00 AM »
It's there George!