Making a fun Humpty Dumpty Egg LASER-cut decoration

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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 🙂

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3D printing an 80x80mm extractor fan housing for LASER cutting

LASER cutting on a cheap and cheerful CNC machine is lots of fun, but I can’t say the same about the smoke and fumes. That’s why I posted before about a simple extraction system. But since then I decided to try to do better using a larger fan mounted on the CNC’s 2020-extrusion frame. So I used OpenSCAD to make a design based around an Arctic Air 80x80x25mm PC fan, as it’s designed for higher airflow than cheaper fans. You can see the result in the photo below.

A photo of the extractor fan housing mounted on the CNC frame during LASER cutting
The extractor fan housing mounted on the CNC’s 2020-extrusion frame

The design did quite a good job and the air flow-rate was quite impressive in my opinion. However, it has the disadvantage of covering a large area so the suction around the LASER-cutting area turned out less than for my previous design. So I decided to adapt the design to allow the fan housing to be mounted to a simple enclosure I’m prototyping for my machine. That led to me adding side supports that stick to the housing and have flanges with holes for bolts.

Using the fan with the enclosure works really well, with hardly any smell of smoke or fumes coming out while LASER-ing, as it’s all blown through a flexible 60mm hose out through a nearby window. You can see the side supports in the 3D assembly picture below. And, if you’d like to have a go at making your own extractor fan from this design, click here to go the Thingiverse page which includes all the STL files and the OpenSCAD design file too.

A 3D image of the assembly of the parts used to build the extractor fan housing and mountings
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