If you’ve read my previous post you’ll know that GCoderCNC is a completely free, open source, web application for creating GRBL-compatible G-Code from SVG files created in software such as Inkscape. Being an online web-app means you can use it on PCs and tablets regardless of the operating system you use, and you can rest assured it doesn’t upload or collect any data about you or your projects.
Even better, it has now been updated to version 1.2 with many internal improvements and a snazzy new set of properties dialogs that let the whole interface be styled using the themes added in v1.1 (below is a picture of the themes available, from colourful to high-contrast for users with vision issues). To find out more, please click here to visit the Github page, or click here to go straight to the web-app to start creating some fabulous G-Code for your GRBL-powered CNC router or LASER cutter.
If you’ve read the introduction to our GCoderCNC 2.5D web app you may be wondering how you can get started using it for some LASER cutting. If so, here’s a quick tutorial that should have you engraving a happy face onto some wood with only a few simple steps and a little time at your CNC machine.
Firstly, opening GCoderCNC 2.5D really is as easy as going to its’ secure website at Github.io. It should launch with the happy face design already loaded as shown in the screenshot below. To make life easy for you, just click here, or on the screenshot, to open the web-app in a new web-browser tab.
The app will have started up in router mode, whereas we’re doing some LASER cutting. That’s easily sorted, just go to the ‘CNC mode’ menu at the top of the app window and select ‘LASER mode’. There’s a screen-grab below showing the menu options. In case you’re wondering, the difference between the router and LASER modes is simply that router mode allows cutting tools to go up and down, and LASER mode keeps the LASER at the same height all the time. For advanced use you can actually use router mode for LASER cutting, using the depth to vary the laser height when cutting thick material. But for now, using LASER mode keeps things nice and simple.
Next we need to tell the web-app what settings are relevant for our own LASER. That really comes down to your CNC machine and LASER module. For example, a 50W CO2 LASER will need much lower power to etch the surface of wood than a 2W diode-LASER. So, if you’re unsure, it’s best to read your manual or ask the manufacturer. I use a cheap Chinese 1610 CNC machine with a 5W diode-LASER, so I find a feed rate of 200 mm/min and 20% LASER-power works well for etching plywood. When you’ve decided, simply move the two sliders at the top of the ‘Default settings’ box, at the left side of the app, to the right values, as in the screen-grab below, keeping the other options unchanged.
Now that the design is all set up we just need a g-code file for our CNC machine to follow. That’s really easy to get: just go to the ‘Export’ menu and select ‘Export G-Code…’ and the dialog box shown below will appear. You’ll notice that the width and height of the finished piece are already set to a default size. If you want the happy face to be bigger or smaller, just change one of those values (the other will change to keep the design proportional automatically).
Now you need to set the ‘GRBL version’ dropdown in the dialog. Older versions of GRBL (say v0.9-ish) used values of 0 to 1000 to represent 0% to 100% spindle motor speed, but more recent versions (say v1-ish) use values of 0 to 255. Don’t worry if that confuses you, as you should be able to find out from your CNC manual or manufacturer. If not, you can try selecting ‘Speed 0 to 255’ and, if your LASER seems to be etching too lightly (spindle speed values are used for LASER power too), you’ll know to use ‘Speed 0 to 1000’ instead. Having done all that you can click the ‘Download the G-Code’ button. Your browser should tell you that it’s downloading ‘happyface.nc’ which should end up in your downloads folder.
If you’ve done all the above then it’s now down to you to make your own happy face. Obviously the first thing you need to do is put some wood on your CNC machine: I used some 2mm thick plywood blanks I bought in Hobbycraft, but most woods should work. Once that’s done and you’ve focused your LASER (and still using LASER-safe glasses and ventilation) you need to move the LASER-dot to the lower left corner of the area you want to burn the happy face into: that’s the default origin and you can see what I mean in the image below.
Now, once you’ve turned off the LASER in your CNC control software, you need to zero your CNC axes in that software. That makes all of the g-code commands relative to that position, or the origin as we call it. If you’re not sure how to do that you need to read your CNC manual as it’s a really important thing to know how to do. And then it’s the exciting bit, where we tell the CNC software to burn/etch our design onto the wood. If all went well, you should end up with something like the one shown below 🙂
Creating g-code files for CNC machines is an essential task for our computer-controlled routing and LASER cutting projects. However, most CNC software packages are either overly complicated or limited to a single platform and operating system. So, to help avoid those issues CNC Maker Zone UK has published its’ own free-to-use and open-source web-app designed for ease-of-use on all PCs and tablets (but not smartphones) including on Windows, Linux, Mac, Chromebook and Android in a HTML5 web-browser.
Below is a screen-grab showing what the web-app, which is called GCoderCNC 2.5D, looks like running in the Chrome web-browser on Windows, with our Darth Vader Head project open (click the image to go straight to the web-app in a new tab). It’s designed as a web-capable app so if you add it to your home screen, in the web-browser menu, you should be able to run it in its’ own window, which is especially exciting when using it on a tablet. And, it’s been designed to create g-code for routing and LASER-ing, and even has some advanced features like variable routing depth for v-carving.
GCoderCNC 2.5D allows you to import an SVG file and export it as a g-code file, all without cookies or uploading your files to the internet: it’s all done on your computer in your web-browser. It’s intended to be usable and useful for anyone interested in CNC making, so hopefully you’ll find it works well for you once you’ve played with it and learnt the basics of its’ use. So, finally, here’s a couple of links to help get you started using GCoderCNC 2.5D:
If you’ve added a Bluetooth wireless module to your CNC machine, you might be thinking of using an Android tablet, or even a smartphone, to do some wireless routing or LASER cutting. If so, you may be wondering what software to choose. So I thought I’d write a short post about my favourite go-to Android app for controlling my CNC machine: G-Code2GRBL which is available on the Play Store. While I can only give my personal opinion, I find it excellent. It gives all of the functions I need in a nicely designed interface, as the screenshot below shows.
Once connected over Bluetooth to your CNC, G-Code2GRBL gives you a range of screens to choose from. The main ‘GRBL Control’ screen gives you buttons for jogging the XYZ axes (with step adjustment controls), buttons to zero XYZ positions, pause/reset buttons and a text-display of the GCode file being sent for routing/LASERing. The file to be sent can be chosen from the ‘Select files’ screen with just a few taps, which is nice. And another useful screen is the ‘Send Commands’ one. It lets you send your own one-line GCode commands for simple control, which is very handy for things like turning on a LASER (on low-power, obviously) for focussing, and turning it off again. Overall, I think it’s well worth a look if you’re after a way to control your CNC wirelessly from Android devices.
Most cheap CNC machines come with a GRBL controller board that communicates with a computer using a wired USB connection. There’s no problem with that if you want a computer near your CNC, but a much more convenient way to communicate with it is over a wireless connection. That way you can keep your valuable PC well away from potential hazards or even use an Android tablet or smartphone instead. And the easiest way to do that is add a Bluetooth module to the GRBL board if it has serial connections available.
So a bit of manual reading, and looking at the boards’ circuit diagram, are necessary. You’ll be looking for connections for connecting wires to its positive (e.g. 3.3V or 5V) and negative (a.k.a. ground or earth), transmit (Tx) and receive (Rx) headers. Normally they’ll be on pins soldered into the board. Then you need a Bluetooth-serial module which are a few pounds/dollars on eBay or Amazon: I used a HC-05 which is commonly available. The module will need its name and communications speed set up first and I’ve put some tips on that at the bottom of this post.
Then the Bluetooth module needs a connection from positive to Vcc and from ground to GND, to power it. The Tx on the GRBL board goes to Rx on the Bluetooth module and, similarly, Rx goes to Tx. I’ve put a diagram below that shows how I wired my HC-05 to my Woodpecker 3.1 GRBL controller board, which is quite common on cheap Chinese CNC machines. Sometimes Tx and Rx connections are reversed on the Bluetooth modules, so if you have problems you can try swapping them over. And to make it easy to get started consider using female-female jumper wires (i.e. sockets both ends) for the connections, like I used in the photo above, before committing yourself.
Hopefully now your Bluetooth module will flash an LED when the CNC is powered, to tell you it’s waiting for a connection. If not, check everything carefully, especially your positive and ground wiring. If that’s OK you should be ready to pair with your PC or Android device and have fun doing wireless CNC’ing.
Setting up a HC-05 Bluetooth module with an Arduino
If you know nothing about microcontrollers then now is probably a good time to find a friend who does, or even try to talk an online supplier into doing the setup when you buy. However, it isn’t really very difficult if you have an Arduino as you just need to wire the HC-05 to it as described for the GRBL board above (see www.arduino.cc for help on your particular board). The code below can then be used to set the Bluetooth module to be called ‘CNC’ (which you can change) with a speed of 115200 bits/second. Most modern GRBL boards communicate at that speed but if yours is quite old, and uses 9600 bits/second, you can change ‘BAUD8’ to ‘BAUD4’ or simply remove that line. And then, hopefully, your HC-05 module is good to go.