Laser cutting your own MDF?

[Ovidius Incertus]

So it just dawned on me yesterday that I have access to a laser cutter at work.  It generally sits idle unless one class or another is actively doing projects.

 

Now, I have no idea how to work the thing or what software you need to use to design shapes, but I can obviously ask one of my art/tech teacher colleagues for help with that.

 

But before I dive down this particular rabbit hole, are there any fundamentals and basic concerns I should be aware of?  What should I know?  I'm thinking it might be cool to zap out a small terrain piece or something just for kicks.

[White Wolf]

I use AutoCAD for my design work, you need to be able to draw in a vector program, another commonly used programme is CORELDRAW.

 

The files need to be exported as .dxf files (generally) for the laser software to understand them. Most laser packages (including mine) come with their own drawing package, but they’re generally not great, most people design in a vector programme and import into the laser package and use the laser programme for modifications and sizing.

 

They are good machines but limited in that they only really work in two dimensions, you need to build 3D models in layers, or have spatial understanding of how to design flat things that build into 3D - I have an advantage as I trained as a civil engineer and can translate drawings into 3D objects.

 

Hope this helps

 

ATB WW

[Exilyth]

Sourceforge has a load of free and open source CAD software you can just download and try out until you find the one that's right for you.

As White Wolf said above: as long as the program can output .dxf, you should be fine.

 

Most proper CAD software takes typed commands like "go to point 42,23 then draw a line to point 23,42", but there's also software which lets you place geometric primitives (points, lines, triangles, e.t.c...) with the mouse. The latter does require some manual adjustment of coordinates though.

 

Most CAD software supports the concept of layers: imagine drawing a part of a picture on transparent paper and another part on another transparent paper - you can easily remove, reorder or translate the papers, enabling finer control of what the resulting image looks like. But CAD pocesses can also use layers to set machining parameters, to tell the machine e.g. "on the red lines, you need to go fast".

 

 

As for design:

- depending on the machine, the laser cuts a hole up to a few milimetres in size, which must be planned for in design.

- depending on how fast the laser is moved over the wood/mdf/whatever, it can be used to burn holes or to engrave patterns. This might require one engraving run and one cutting run to get a part that is both engraved and cut out. Some machines can control the power of the laser to do this in one go. They usually require another layer or CAD file for this to set the parameters of the different pathes.

- a square hole of [materialwidth] in height in one part and a square peg on the other part can be used to connect parts orthogonally

- similarly, a https://en.wikipedia.org/wiki/Dovetail_joint can be used to join parts on edges. Such a joint requires [materialwidth] on both parts, e.g. a square building of 4" would consist of four walls witth [materialwidth] on each side being the joint (where the other walls slide in) and 4"-2*[materialwidth] being the actual wall, which can be decorated with windows, doors, e.t.c...

- pen and paper are great for sketching out a design before starting any CAD work

- removable roofs are nice to have on buildings which are not ruins

- talking about buildings: most buildings are just boxes with a roof and some holes in the walls, or a collection of such boxes.

 

 

As for the actual production of parts:

- unless you have a pair of replacement eyes handy, ALWAYS wear laser protection goggles and don't operate the machine when the enclosure is open.

- plan for a few test runs to get the scale right before batch producing anything

 

 

The reprap project is all about building 3D printers, but they've got a page on their wiki about how laser cutting works:

https://reprap.org/wiki/Laser_Cutter_Notes

and a page on laser safety:

https://reprap.org/wiki/Laser_Safety

They also have some advice on building your own laser cutter, but you probably don't need that if you have access to a device.

 

 

... did I mention the need to protect your eyes yet?

Eyes don't grow back - better to protect them and have nothing go wrong than skip protection and never look at 40k the same way again.

 

I hope that's not too much of a wall of text.

[Ovidius Incertus]

Many thanks, fratres.  This is a great place to start!