Carving with CNC


The CNC machine has had a few upgrades since my last post. I will list them at some point. The machine now is at a pretty good stage – still a few niggles. To celebrate I thought I would have a go at carving wood with it – I have only used the machine for 2D cuts in sheet materials so far. The software I am using, Estlcam, lets you get into 3D carving.

The toolpath created by Estlcam. First pass is a ‘roughing’ linear cut from left to right, then a finer ‘finishing’ cut which follows the on-plan circles of the waves

The Wood

I used a lump of LVL beam which, for the past 5? years has been a lamp base. I did not grab a photo of it – imagine a block of wood…it was like that. I actually found the lump on the beach, though it’s hardly ‘driftwood’ really and in hindsight, it could have been fished out of a builder’s skip.

The 3D Model

I generated a 3D model to carve in Rhino with Grasshopper. I was aiming at creating the shape of the propagating waves you get when a (rain)drop hits a water surface. I was too lazy to look into the actual mathematical form of this shape, so I used the equation for a damped oscillator since I had that at hand. Can’t find the GH file – probably didn’t save it. Was on my old laptop anyway.

Rhino render of baked Grasshopper geometry. I’ve lost the Grasshopper file.

Using Grasshopper I plotted this function then I did a ‘revolve’  to get the surface. Sliders for the various parameters let you fiddle with the shape to suit the piece of wood.  I played with the sliders until I got the shape I was after.

CNCing

I discovered I can do a time-lapse video on my GoPro, so I videoed the machine at work. It’s quite satisfying to watch, though hardly cinematic gold. The battery on the GoPro ran out, but you get the message.

Finishing

I actually got bored with the CNC when it was doing its second-pass finishing – my dust extractor thing had blocked so I had to brush away all the sawdust. I figured I could do the finishing way quicker by hand, and I was going to have to sand it anyway. It took about 20 minutes to sand, with the help of a Dremel hand tool.

There was an ‘incident’ during the milling process when I decided to take over control and drive. Unfortunately, I had not moved the tool up enough and so a carved a furrow out through the waves. You can see it in the photo. I filled up the rut with Araldite mixed with sawdust.

I went overboard with the gloss lacquer. Hate that look: Tacky. Enough said.

Too shiny.

Reinstating as a Light

The light fitting I bought from the DIY shop. It was actually a weird pendant extension, which is actually kind of clever for us house-renters who get stuck Ebenzenzer Landlord’s light fitting. I cut the neat little adaptor that goes into the bulb receptor off and connected a switch and mains plug.

 

 

 

 

 

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