Saturday, June 04, 2016

Laser Pirate Craft

Since the laser cut Unicorn Lamp was such a huge success, and to stem any cousin rivalry, I asked The Child if he wanted a lamp, too, and what kind he'd want.  He thought a moment and said pirate.  I figured it would be fairly simple to adapt various pirate flag symbols.



I think one title for this photo is "Putting the Sir in LASER."  I was sort of going for the Agatha Heterodyne look, but I missed (probably because I don't have fabulous blonde hair).









I went to the Eugene Maker Space with the design all ready to go as both an SVG and DFX file.  The CAD software seems to see DFX files more readily, so I used those.  And then I hit a problem.  The shop's laptop went into sluggish mode; after two reboots, restarting the CAD and preview software multiple times, and an infinite amount of tweaking line widths, I finally managed to get the laser cutter's control panel to accept that I wanted to cut the design the CAD software was sending it as a linear design (which would cut) and not a rastered one (which would only engrave).  I'm still not sure what I did, because after an hour of more-or-less doing the same configurations, the design suddenly appeared in the preview.


When the design is in red, the laser will cut through with a continuous line.  The photo to the left is the CAD software, and it's mostly a reminder to me that I need to set the line-width to zero, and the line type to continuous.












The laser cutter's bed is twelve by sixteen inches.  I forget the depth.  This is a view through the window; I keep the window covered when the laser's fired up because there's some debate about how laser-proof the window really is.

After two cuts, there's a lot of scorching.  In this case, scorching isn't so bad, and it adds to that "I've been in a pirate battle" that I want.








I was able to lift the frame of wood straight up and the pieces fell out and stayed within the laser cutter bed.














Originally, this was Calico Jack Rachham's flag, but the sides of the box were too narrow for the swords to be crossed underneath the skull, so I gave them their own design.  The skull's three inches wide.













If I had shrunk the design down to fit on one side, the teeth would have been too small for the laser to cut out.  I need to take a look at the kerfing gap the laser makes between two adjacent pieces of wood, but generally laser cuts can't be too much closer than an eighth of an inch before you start to get artisanal charcoal.  As it is, there's a weak spot in the skull design where the jawbone hinges.






Speaking of artisanal charcoal, last week when I tried to make super-small Penrose tiles, they fell out of the main sheet of wood and if they fell off the support grid shown here, they'd char when the out-of-focus laser would pass over them.








The back side of a skull panel.  Even with a double-cut, part of the design didn't make it all the way through the wood.  I still can't figure out what's changing, but it's probably a combination of different wood densities, different concentrations of layer adhesive, and possibly enough of a warp in the wood to take the laser out of focus enough that it doesn't cut.  Oh, and extra smoke.


The back sides of other panels.  It looks like a denser grain may be the culprit. I think the straight vertical line off of the right-hand eye is a score mark from the metal supports (maybe the laser heated it up?)



A dagger, a heart (about to be pierced), and an hourglass.  All taken from various pirate flags.  Pirates took many of their flag symbols from gravestone markers.  


Here's an example of foreground and background.  I'm including it to show what the limit of the cuts are.  The teeth actually came out as recognizable pieces of wood instead of lumps of coal.  I managed to skirt the limits of the wood's strength... I think if I were doing this again, I'd put about an eighth of an inch more between the skull and jaw cut-outs, because the skull panels are a little fragile.







 More piratical woodwork.
The box assembled, but unglued.  In the back is the lid with a larger dagger design on it.


The lid -- this is the underside, and the smaller square will fit within the box.  The dagger design is a slightly modified dagger from the other design and will sit on the top.


Arrh!  I'm pretty sure that the char marks on the outside will stay that way.  We've got some left-over glow paint, so I asked The Child if he wanted the inside to glow, and he did.





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