Introduction: CNC Etching With the Sun
I don't remember who taught me you could burn stuff by focusing the sun's light with a magnifying glass, but I do remember how cool I thought it was. I felt like I was making something out of nothing. Whether it was dried leaves or the unfortunate helpless insect, I loved burning things with a magnifying glass.
A while back I bought a 2.5 watt Eleksmaker A3 laser etching machine. Once I got it put together and all the software running, I was super excited to start "burning stuff"! Unfortunately, it worked for all of about 10 minutes until the laser diode failed and I was left without the opportunity to see what the machine could do until the replacement laser arrived from China.
While I was waiting I came up with this idea to use the power of the sun to do the burning for you. It turned out to be actually quite simple if you can get your hands on the proper equipment, and I will show you how I did it.
Step 1: What You Need
In order to try this, you will need:
- A CNC or laser etching machine, or really anything you can use to control the X/Y axis - I used an Eleksmaker A3 laser ordered from banggood.com
- A magnifying glass with an armature you can attach to the machine's gantry
- Software to control your machine. I used Zax's t2 laser software that was written for these "benbox" laser machines. It is paid software, but you can get a demo at benboxlaser.us
- Wood or something else to burn
- Text or a simple vector design to burn
- A sunny day
Step 2: Attach Your Magnifying Glass and Focus the Light
How you connect it depends on your magnifying glass, but I would highly suggest using a "Helping Hands" glass for ease of connecting and adjusting. The armature allowed me to connect it vertically so I can raise and lower it as required to focus it as tightly as possible on the wood. As soon as the wood starts burning, lock it in place and block the sun until you are ready to burn.
Step 3: Import Your Design or Text
Depending on the software you use to control your machine, you will need to either import a vector design or enter some text. The most important thing is to change your machine settings slow enough to allow the design to burn into the wood, and to move fast enough to keep it from burning when it isn't meant to. In the T2Laser software the feed rates are set using the "running man" icon. The settings I used were 100 for the "Vector feed rate" and 1000 for the "Rapid feed rate". The engraving rate doesn't really matter because we won't be engraving at all.
Step 4: Engrave Your Design
Finally, uncover your magnifying glass and check to make sure the light doesn't need to be refocused. If everything looks good, you can start sending your program to the machine to begin burning. If it isn't burning, try refocusing the lens better or slow down your feed rate. Check out the video of mine burning on the 4th of July.
4 years ago
Hello, i had a similar idea to use a magnification glass of 80 or better 100mm, but istead of the sun i thought would suggest a hologen lamp of 500-1000W this way you are independend from the sun and its easier.
Reply 4 years ago
I did not realize that would work. Unfortunately I don't have a 1000W halogen lamp laying around or I would try it. Great idea.
5 years ago
I've always been wanting to do this!
5 years ago
5 years ago
Fun! Great that you're doing this with a "stock" xy rig so you can do an instructable. We built a custom rig like that in 2010. Lawrence even wrote a script to compensate for the sun's motion. That's a must if you're going to etch out complex designs. https://www.youtube.com/watch?v=-x1xiT70yXk Sadly this was long before I had a blog, so the build was never written up.
5 years ago
That's impressive, I didn't realize you could get that much precision using a magnifying glass!