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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.
It’s Easter season in CNC-land, so I thought I’d have a go at designing an egg themed project. Of course, the most famous egg is probably Humpty Dumpty, and he’s also a nursery rhyme character so a fun project even if you don’t do Easter celebrations. So I came up with a simple design that can be LASER-cut from thin wood sheet on a CNC machine even with a low-power diode-LASER. I also decided to make the design symmetrical, and add a small registration mark in the lower-left corner, so it can be cut and engraved one side, flipped over without removing the sheet, and just engraved on the back. The finished project is shown in the photo below.
As you can see in the photo, I cut two versions from 6mm thick Basswood around 80mm high (using my GCoderCNC 2.5D web app – click here to launch this project there). That turned out to be a good size as I’d cut them at 90% power and 100 mm/min feed rate with 4 passes, so small areas of burning next to lines didn’t spoil anything and were easily sanded away. If you look closely you’ll notice that the engraved lines in the right-hand version are slightly mis-aligned. That’s because I made them two-sided: so I was quite happy that they turned out looking OK on the rear.
The smaller version was cut from 1.5mm Cherry wood, at the same LASER settings but just two passes. It’s smaller but turned out quite well, with just some charring around the eyebrows that was hard to remove. The Cherry was a little thin as the legs and arms were narrower than the larger Basswood versions, so I cut two and stuck them together with wood glue for added strength. Overall though, for a quick design I was quite pleased with the results, and I hope you enjoy making one too 🙂
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:
Sometimes it seems like there’s no end to the range of projects we can make with a CNC machine. And it’s quite amazing that even cheap versions are accurate enough to make miniature projects for model scenery and even dolls houses. So I thought it might be fun to try making some miniature fruit crates, as the photo above shows, and post the design here for anyone to have a go at making some too. At full size they would be around 450mm long, 300mm wide and about 200mm high but at 1/12th scale, commonly used for dolls houses, they’re much smaller: I’ve included a photo below with a one pound coin for comparison.
I’ve put an SVG file below for you to download, or you can click here to launch it in the GCoderCNC web-app. If you need to edit it, or make a DXF file for your CNC software, you can do that with Inkscape quite easily. The red box is there in case you need to get scale in your software, but doesn’t need to be cut: it should be 70mm wide by 65mm high for 1.5mm thick wood (or other materials such as plastic, or even cardboard, if you prefer). If you use thicker material you can scale it proportionately, such as 2x scale for 3mm thickness. The design works for LASER cutting but can be adjusted easily for routing by offsetting the lines through half the cutting width.I LASER-cut a prototype in Oak (the one on top in the photo above) and the rest in Basswood, both from 1.5mm sheets. Once cut they are quite simple to put together. I started by putting the sides onto the bottom of the crate, then slipped the ends on one at a time. I also used glue at all the push-in joints: the base could be left floating but the glue helps prevent the thin pieces of wood at the joints breaking away when sanding. To finish the crates off I used 400 and 1000 grit sandpaper, including using a finger sander, followed by a couple of coats of Danish Oil to give the wood a nice look without too much of a shine. Personally I’m quite happy with the results and hopefully you’ll enjoy making some on your CNC machine too 🙂
Recently I bought some 1.5mm thick Walnut sheet as I wanted to try it out with my CNC router and see how good the results would be. Walnut is quite a dark wood with a nice dense grain, so it seemed like an excellent opportunity to take my CNC intergallactic by making a small inlayed Darth Vader from Star Wars. Hopefully George Lucas will approve if he happens by, so below is my completed Darth Vader head (at around 10% water content, in case you’d like to know).
I was quite pleased with the results, the details being routed to 0.75 mm deep in two passes, and the edge being cut in three passes, using the 1.2mm diameter end-cutting bit shown above (which gave finished grooves almost 2 mm wide). As the image at the top of this page shows, the Walnut sheet cut quite well and cleanly with the spindle at 1000 rpm and a feed rate of 50 mm/min to minimise potential breakage of the bit. The above photo is then after I’d given it some sanding with a fine grit paper, which took little work. Even sanding out the recesses with folded over sandpaper was quite easy, with a little patience. So overall I’m looking forward to some more small projects using this lovely wood.
