27 September, 2012

Spawn Point Sign

I have cut signs before, and they are typically not really worthy of a blog-post in their own right unless I am doing something new or unusual. In this case I decided to experiment in art concrete. Art and concrete are generally not two words you hear in the same sentence, but believe it or not there are people all over the world making art and craft pieces from your regular off the shelf diy store concrete.

So being an adventurous sort I thought I would experiment in a bit of concrete casting. It's perfect for objects where you need to make many duplicates and for objects that will remain outdoors.

First I needed a 'plug'. A plug is a 1:1 scale model of the thing which you mean to cast. In this case a spawn point sign for a local airsoft field.

If you have read any of my other CNC posts you will probably be familiar with the phases of a CNC project:

1. The idea in my head. bing! lightbulb moment! I wanted something that would be simple, indicative of it's purpose and look kind of contemporary mixed with something you might see in a first person shooter.

Designing the sign in SolidEdge 2D
2. I then draw the idea in 2D. I used SolidEdge 2D Drafting.

Designing the toolpaths in CamBam
3. I then design the movements (a.k.a toolpaths) of the cutter.

The toolpaths imported into EMC2 CNC controller
4. Finally I feed the toolpaths into my CNC control software in the computer attached to my CNC router.

Then it's a case of locating the plywood to be cut onto the bed of the CNC router and setting the CNC controller off.

During the cutting phase.
CNC cutting often surprises people with how long it can take. Even a very small 200mm x 200mm and relatively simple sign like this takes over an hour of continuous noisy cutting. 

Eventually the sign is produced, and after a quick clean with some P180 sandpaper it looks like this. All perfect with clean crisp lines. Just imagine trying to make this by hand.

Cut and cleaned
As I am going to be casting this sign I need the surface to be smooth so the casting medium will release the plug. I gave the sign a quick spray paint in white gloss.

The plug, all painted up ready for casting.
That's it for today, I need to leave that paint to dry for at least 24 hours. In the next post I will cover my casting experiments. Thanks for reading!