Alphabet Hooks: G

This is an ongoing project marrying typography with DIY crafts: transforming letters into multifunctional hook-pendant-bottle-opener-fidgets.

I started with letter G with no particular reason except for that the lowercase version is the most complex letter in the alphabet, hence there's lots to tweak and play with.

I suggest anyone attempting this project to choose their preferred letter in their favourite font!! The fonts are really the fun bit. Comic Sans, anyone?

The letter G was firstly 3D printed which served as a mould for subsequent metal casting. You may cast using a variety of techniques and metals/alloys, up to you! Below I'll explain how to sand cast it using aluminium.

Software used:

1. Adobe Illustrator: prepares the linedrawing of chosen letter in chosen font.

2. 3D software (Solidworks, Rhino, whatever works): import linedrawing, trace it, and extrude it. Creates the printable digital model.

3. Slicing software (Cura, Slic3r): import STL file and determine the print strategy.

Here we go...

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Step 1: Download the Files

Here are the original files that I used to make this hook.

However I recommend to use these mainly for guidance as the core of this project is really the customisability: the letters and fonts people like vary widely. For example, the PDF gives you an idea of the several wonderful forms that a G can have.

If you simply want to make a test piece with minimal effort, then the STL file is the one I printed.

Step 2: Create Linedrawing of the Letter

Choose a letter and go through all the fonts you have installed in your computer. Pick your favourite(s).

In Illustrator, activate the letter you want to craft and go to Type > Create Outlines. This converts it into a vector linedrawing.

You now can edit the outline of your letter to add more functions to the form. For example, I transformed the top right bit of G into a small claw-like hook. I also separated the bottom area and moved it downwards to create another, hanger-like hook.

Once you're happy, export it as DXF file.

Step 3: Make 3D Model

Import the DXF file into your 3D program. Trace the outlines and extrude to your preferred thickness.

TIP: use a special feature called 'draft angle' when you extrude the outline. It will make the subsequent sand casting affair much easier. My model doesn't have a draft angle (meaning the edges go completely straight) which caused a lot of trouble when making the sand mould.

Add small fillets to the edges, makes it look nicer.

Export it as a STL file.

Step 4: Slice the Model

Import the STL file to a slicer program such as Cura or Slic3r. This prepares your model for 3D printing.

For example, my letter was printed in PLA using a layer height of 0.2 mm, 6 top layers, 3 bottom layers, 2 wall layers and 0% infill. No support, no brim (only a skirt). Printable only in 30 mins.

If you're printing at a local fab lab, it's better to check with them what printers and filaments they have available. They can advise you the best. Simply bring this STL file with you.

Step 5: 3D Print the Letter

This will be your mould for metal casting. However this plastic letter hook can also be your end product!

Step 6: Prepare the Sand Box

If you're sand casting your metal end product, then get yourself a wooden frame that fits your letter leaving room around edges, and some moulding sand to fill up the frame. FYI it's a special aggregate of sand, bentonite clay, pulverized coal and water.

Pack the sand around your letter very well, leaving no air trapped. Build up in thin layers and use a press tool (such as wooden stick) to tap the sand firmly and evenly. Fill it up to brim.

Step 7: Remove Letter From Sand

This is a critical step! Many things can go wrong here and it takes some practice to master it.

So turn your sand box downside up and your letter will be revealed tightly packed in sand. You now need to fish it out so that it leaves behind a perfect imprint. This is where the draft angles can really come to your aid: it will be much easier to lift up your letter.

I used a 3D printing pen to make quick DIY hooks but it was still very problematic to remove the G. My model had straight edges which meant it partly ruined the imprint: the enclosed areas, for example, took the sand out with them. I manually reinserted the sand in the imprint. The sand mould was okay-ish.

Step 8: Cast Molten Metal

I used molten aluminium to pour into the sand imprint. Follow safety precautions: the metal is blazing hot even if the colour doesn't seem to reflect it.

Step 9: Sanding, Filing

Pouring molten metal isn't a precise technique. There's always surplus material that's attached to your product. My G was stuck on a metal plate several mm thick. I firstly used a grinding machine to completely remove this backing. I then used hand files and a saw to remove all remaining excesses. It will take (a long) time, but patience leads to success.

Step 10: Polishing

You may want to polish your metal product for smoothness and shine. I used a polishing machine for superb finish. But I also didn't go too crazy and left some areas intentionally rougher. 'Front' and 'back' sides differ which is fine by me but if it bothers you, use a grinder on 'front' side as well.

Step 11: Enjoy Your Hook (pendant, Bottle Opener, Fidget)

I'm positive you'll find many more uses for it around the house.

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