Secret message leather knife/tool handle

A current @Jagmills project at the space involves making a handle out of leather disks, a type of handle commonly seen on knives and other hand tools:

In the rough:

And as a finished fully shaped handle:


@Jagmills currently has three different colours of leather pieces which he has laser cut to form the handle. A discussion about his work prompted @AndrewPatience to contemplate the idea of encoding a secret message in the construction of the handle.

The idea of using Morse represented by the different colour bands evolved. With three colours available it is possible to use one of them to indicate the break between Morse characters and the other two for the dot and dash symbols. It would be possible just to use two colours and so increase the number of symbols available for the message.

Exploring the idea showed up two challenges, calculating how many disks might be needed to convey a particular phrase and having a visual representation of the message to assess its aesthetic qualities.

For a little bit of fun I decided to try to mock up something to help with the design process, something which could convert text to Morse, give an estimate of the number of disks required for a message and offer some visual approximation to what it might look like.

Rummaging in my box of tools, I took out a RaspberryPi based copy of Mathematica.

The basic strategy was to convert normal text to Morse text, a string of dots, dashes and spaces between words, then to convert the Morse text to character codes and finally replace the character codes with appropriately coloured graphical elements to represent the arrangement of leather disks.

ToMorseCode[“a secret message”] -> ".- /… . -.-. .-. . - /-- . … … .- --. . "

handle2D[“a secret message”, colours] -> leather_bands

And the same process in 3D:

handle3D[“one less trout”, colours, True] -> leather_morse_handle_3d

Mathematica notebook here and in PDF form here.


This looks fantastic :slight_smile:

I have cheekily moved your post to the members only place for now, as the person this is a present for has been a visitor to the forum a few times!

I hope to write up the rest of the project properly soon, but I am close to finishing it. I can’t wait to see what the end result looks like.

@stochastic_forest are you planning to be in the space Tuesday/Friday next week? :slight_smile:
I really need to finish this off when I get back!

Hi Chris,

Hope the trips aren’t proving too arduous. I"ll be around next week, Tuesday maybe the Christmas meal , we probably need to take a final decision on that very soon, but Friday should be fine !

Obviously a brain fart there, as the Christmas meal is next week, so I’ll be around tonight :slight_smile:

The glue up begins!

Looking good. Love to see the finished product.

Also like the banana for scale though salad might go with cow better. (as per example below).

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Looks like the original Shmakerspace sandwich, built to last a lifetime!

Some more progress! Trying now to decide which I prefer, looks and usefulness wise:

Other option:

Really pleased with how the handle is looking thanks to @stochastic_forest and @AndrewPatience 's Mathematica wizardry!

Looking awesome !

Sadly I forgot to take a fully finished photo before delivering said present.

Here is the last shot I have. This is the last coat of finish (an interesting concoction called “OB’s shine juice” which is actually amazing) going on. I designed it so the pommel part could be fitted last, to give my lathe somewhere to grab on to for this process.

I must say I am very pleased with the results, as was my father :slight_smile:


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That looks amazing!
Brilliant work, I hope all the details of the handle are noticed.

Shinier than the shiniest shiny thing ! Looks fantastic :slight_smile: