Thinking of building a DIY CNC laser cutter?

Building a DIY CNC laser cutter isn’t for the faint of heart. If you’ve decided to take it on as a project, realize it’ll probably save you neither time nor money to build your own. Yes, you can build a “mini” version using old computer parts, but the reality is that duplicating the functionality you get from a professional unit is not likely to come much cheaper than a low-end Chinese import.

Fast, Cheap, Not Very Accurate, But Easy

If you’re the sort of person who just wants to point, click, and burn things, yes, you can probably do it in not much more than a week or two.

Thanks to the wonders of the Internet, comparatively powerful laser diodes are dead cheap. The personal computing revolution has also made fairly precise linear movements (in the form of discarded scanners) readily available.

Some basic woodworking and a bit of metal stock combined with rudimentary digital electronics later, and you can put yourself together a fairly functional unit capable of cutting paper… the “Mad Max” laser cutter, if you will. By the way if the process of doing this isn’t fun i.e. you’re just building your own laser cutter to save money, then don’t do it. You can buy a quality laser cutter (way better than
DIY) by going to a USA CO2 laser cutter retailer here.

One example is here: http://www.instructables.com/id/Laser-cutter-start-slicing-stuff-for-under-50-dol/?ALLSTEPS

These units, like anything that could be considered as the post-apocalyptic answer to modern materials processing systems, do have a few drawbacks. For one thing, safety interlocks.

Specifically, there aren’t any.

The high power laser diodes that there are capable of doing significant damage to your eyes, and these systems won’t do a thing to stop it.

There’s a running joke in the laser world, “do not look into laser with remaining eye.” It could very well apply to the lasers used here.

Certain high power laser diodes available on the used and surplus market aren’t just capable of causing you serious harm if you stare down the beam. Some of them will cause permanent eye damage if you so much as look at the (invisible!) spot they make when pointed at a white or reflective surface.

How is this possible?

Unlike CO2 lasers, whose beams are stopped by the surface of the cornea, small cheap diode lasers operate in the near infrared range. The light waves here are focused by the eye just as well as regular visible light. This means they can be focused to a point — a very small point — on the retina of your eye.

As it happens, focusing a very bright light to a very small point is precisely how laser cutters and engravers remove material.

While the light radiating from a spot on a piece of paper or the wall is much less powerful than the direct beam needed to burn or engrave, your retina also has a vastly lower damage threshold than a piece of paper, too.

Therefore, if you venture down the DIY CNC laser cutter path, your first and certainly your best investment ought to be a pair of high quality, professional grade laser safety goggles.

Not just any pair, either. Make sure they’re designed for the type and wavelength of the laser you’re planning to use. Safety goggles meant to protect you from a 532nm-wavelength argon laser will do nothing against a 1064nm diode laser, even if they still make you look cool.

diy cnc laser cutter

Yes, safety goggles can be more expensive than the (cheap, used) laser itself. On the other hand, laser diodes are replaceable if they break because you bought the cheap one. If you damage your eyes — which has happened to too many laser hobbyists — you’ll be seeing the consequences for the rest of your life.

Building a Real Laser Cutter

Still here?

Great, persistence and determination in the face of obstacles and scary warnings is key to successfully executing a complex DIY project like a laser cutter.

Unfortunately, it’s also too complex to even begin to describe in the space of a short article.

In a nutshell, you’ll need to have or arrange yourself access to basic materials processing facilities. Not just a good drill, saw, and the like, but, ironically enough, having access to a laser cutter will come in very handy.

You’ll also need a basic understanding of digital electronics, and some experience with the fine art of getting printed circuit boards made.

Lastly, you’ll need $1k  in spare cash to devote to the project… however much you think, and then a good 30% extra.

Where do you find plans?

Unfortunately, there aren’t any worth while  “how to build a laser cutter” plans worth following.  However, there are some very well documented plasma and CNC laser cutter projects that others have completed, like this one: http://www.buildlog.net/cnc_laser/index.php

You can see a video of it in action here:

 

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