The Smell of Molten Projects in the Morning

Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.

Tag: Art-ish

They might be Art

Layered Paper: Mariner’s Compass Block

The Mariner’s Compass pattern on page 133 of Jinny Beyer’s The Quilter’s Album of Blocks and Borders:

Mariners Compass – Beyer 133

Becomes a laser-cut layered paper design:

Layered Paper – Mariners Compass – Beyer 133

A face-on view with different colors:

Layered Paper – Mariners Compass – Beyer 133

This seemed like an appropriate use for the stack (well, several stacks) of colored paper I’ve accumulated over the years.

The illustration in the book is apparently a photograph of a quilt block Beyer put together, so I had to reverse-engineer the Platonic Ideal Block from the image:

Mariners Compass – minimal shapes – LB layout

Fortunately, after a bit of fiddling around, I could take advantage of the radial symmetry to duplicate most of the fundamental shapes, so producing the layout really wasn’t all that difficult:

Mariners Compass – LB layout

The blue tooling lines (upper left) run along the centers of what would be seams in a fabric block, with 2 mm circles defining the endpoints for ease in snapping the lines.

This being the first block I attempted, I did it all wrong. LightBurn can form the convex hull over a group of shapes, so I just selected pairs of circles, created the hull, and iterated for the minimal shapes required to generate the whole design. That produces the basic layout, but what you really want is the collection of shapes between those hulls that define the actual cutouts, which appears in the lower left image.

Don’t do it that way, as explained tomorrow with a different block.

With all the shapes in hand, you duplicate them for all the paper layers you need, removing the shapes corresponding to the color of each sheet. Sheets lower in the stack have fewer cutouts, with the pattern in the lower right being second from the bottom.

The four holes in the corners fit over rivnuts in a fixture aligning the sheets in a tidy stack:

Layered Paper – alignment fixture

Yes, that’s a blooper sheet.

All in all, it’s easier than I expected to get nice results.

2023-10-16
Layered Acrylic Smashed Glass Junk Collector
What else would you call it?

Layered Acrylic Desk Junk Collector – overview

It’s a test piece with adhesive sheets between acrylic layers:

Layered Acrylic Desk Junk Collector – edge detail

From top to bottom:
- Acrylic 4.3 mm – sidewall to corral the junk
- Acrylic 1.5 mm – top plate
- Acrylic 2.4 mm – two layers
- Acrylic mirror 3 mm
- Cork 2 mm – PSA backing
The pair of 2.4 mm layers add up to just an itsy more than the 4.8 mm thickness of the shattered glass atop the mirror. Unlike previous epoxy sealed coasters, the glass sits on a sheet of 3M LSE adhesive film to keep the pieces together, with the top 1.5 mm acrylic layer containing any slivers. Because there’s no epoxy involved, the project is finished with no muss, no fuss, no curing time, and no drippy edges.

The geometry comes from a scan of the glass piece:

Desk Clutter plate – smashed glass – Quick Mask

That’s the GIMP Quick Mask result of manually drawing around the perimeter with the center of a 25 pixel diameter pencil, thus creating a 12 pixel gap to ensure the glass will fit inside the cut shape: at 300 dpi, the 12 pixel gap is about 40 mil = 1 mm wide. Slightly less would work as well, although I’ve discovered some of the glass cuboids have non-vertical walls sticking out to the side above the scanner’s depth of field.

Scribbling over the interior with a bigger pencil clears it out and a few fill operations produce a binary mask perfectly suited for LightBurn’s Image Trace tool:

Desk Clutter plate – smashed glass – binary mask

Trace that outline into vectors, throw away the mask, and use the outline for a conformal cut.

The rings of acrylic and adhesive are 3 mm wide, generated from the outline by offsetting it 3 mm outward:

Desk Clutter plate – LB perimeters

The tooling circle around the perimeter simplifies drag-and-drop alignment, because the geometric center of the perimeter shape isn’t quite in the middle of where you’d (well, I’d) want to align it. Grouping the outline with the circle keeps the center snap point where it should be.

Narrow rings of adhesive sheet turned out to be even more unmanageable than I expected. Perhaps a better way:
- Cut the ring with tabs holding it to the center area
- Stick the ring + center to vinyl transfer tape
- Peel the protective paper off the adhesive ring
- Stick the acrylic ring atop the adhesive ring
- Sever the tabs to release the adhesive ring
- Peel the transfer tape off the ring
The “adhesive tape sheets for craft” are paper-based, rather than a plastic film, and are neither transparent nor durable. I used it mostly to get an idea of how well it sticks to acrylic, as it’s primarily intended for paper crafts.

The 3M LSE backing layer is plastic and the sheet becomes nearly transparent as the glass squishes down, although you wouldn’t want it on a mirror where you cared about the optical quality of the reflection. Underneath a chunk of smashed glass, it’s just fine.

All in all, it turned out well.

Next: how long does that craft adhesive last in abnormal conditions?
2023-10-13
Blockface Grips From Warped Acrylic
This is definitely not recommended practice:

Laser-cutting warped acrylic

It’s the sheet of 3/8 inch = 9 mm vintage acrylic that Came With The House™ and what you see is the relatively unwarped result of several months of pressure. The wood sheet in front puts the left edge mostly flat on the platform, with the steel disk weighting the rear end down; the front end sticks out through the laser’s pass-through door.

The general idea was to cut a rectangle that would be flat enough for the shapes I actually needed:

Blockface grip cutting

They’re grips for a set of Blockface printing shapes. The alert reader will note the rectangle sits atop three spikes, not the usual four; it was flat enough for the purpose, not actually flat.

The OMTech laser claims to be 60 W, but has an over-amped 50 W tube that’s barely adequate for the task. The cuts required two passes:
- 5 mm/s @ 90% cuts almost all the way through
- 10 mm/s @ 90% clears the cut enough to have some shapes drop out and the others be easily pushed through
Cranking the tube current that high isn’t recommended practice, either, but sometimes ya gotta do what ya gotta do.

All’s well that ends well, though:

Blockface grips in matrix

I also cut the Blockface shapes from double-faced adhesive foam and stamp pad rubber:

Laser cutting rubber stamps

To my utter astonishment, the rubber cuts did not smell like a tire fire and the neighbors did not rise up in arms.

I cut several sets of grips / foam / rubber and sent them off for final assembly. The recipient seems delighted with the results and has been hand-printing up a storm.
2023-10-12
Wood Inlay Earring

Trying a sequence of offset and raster filling produced a credible 0.5 mm deep inlay pocket in a chunk of acrylic:

Earring samples – veneer spade recess

The odd pattern inside the pocket comes from the offset fill:

Veneer spade pocket – LightBurn preview

Combining the two fill patterns produces a smoother bottom in the pocket, but it’s a good thing nobody will ever see it from the back side, because the offset fill concentrations chew through the entire 3mm sheet.

A spade-shaped adhesive sheet bonded the veneer into the pocket, after which I sanded the surface flat with 200 grit sandpaper and hit it with some polyurethane sealer. Next time I’ll knock the finished surface flat with 400 grit paper.

The gray acrylic disk has a rebate around its rear rim for the “gold” ring, with the adhesive disk gluing the black disk to the front:

Earring samples – veneer spade parts

Which looks like this when it’s stuck together:

Earring samples – veneer spade side view

I don’t like the raggedy surface of the rebate above the ring, although it’s not too awful in person.

Having gotten reasonable results with the acrylic pocket, I cut an acrylic spade and stuck it in place with another bit of adhesive sheet, leaving it standing proud of the surface:

Earring samples – veneer spade acrylic

The red earring used up one of the hundred slugs left over from the capsule plate; I’m ready for a surge in demand.

The adhesive sheet is workable in disk form, but the spade shape is entirely too fiddly. A dab of acrylic adhesive would likely work just as well and be easier all around.

Stipulated: they’re cute, but not that cute.

2023-10-11
Magnetic Stirrer Resurfacing & Mug Decoration

Half a year of plunking my morning cocoa mug on the magnetic stirrer had pretty well scuffed up its platform, so this seemed like a good idea:

Magnetic stirrer – vinyl surface

Rather than add the blue disk to the small-scraps collection, I converted the Squidwrench logo into a LightBurn layout:

Squidwrench logo – laser cut layout

The roll of transfer tape I have on hand doesn’t stick well to the polyurethane sheet, so easing the vinyl onto the mug required careful tweezer work:

Squidwrench logo on mug

It’s on the other side of the mug from the original, somewhat battered, logo.

Now we can learn how long polyurethane sheets survive under the same conditions.

2023-08-25
Danger Zone Earrings: Wood Edition

They’re not fancy marquetry, but they look pretty good:

SCP Earrings – wood veneer

The darker areas are laser-engraved with the usual SCP warning label geometry.

The left set was engraved through blue masking tape, which increased the exposure, added no benefit, and required fiddly cleanup. Won’t make that mistake again.

The middle one has the darkest wood of the set with the lighter part not exposed to the laser.

They’re slightly smaller and much lighter than the plastic versions in order to fit them on the remaining DIY veneer plywood from the knitting stitch counters.

Rather than make another fixture for the backside branding, I cut adapters using the two outlines and dropped the hollow triangles into the fixture:

SCP Earrings – wood cutting fixture

Two layers of veneer feel about right, although the layers should not have their grains oriented in parallel as these do. The PSA sheet on the back veneer holds them together, but they’re too flexy for confidence.

The contrast between gentle natural wood (using a generous interpretation of “natural” for veneer with a PSA layer) and the SFnal SCP warning label symbology is definitely amusing.

2023-06-28
Danger Zone Earrings: Einsteins!

A chance encounter in the acrylic scrap box led to a radioactive einstein:

SCP Earrings – Radioactive einstein

That was so easy it’s gotta be either criminal or sinful.

A few test on scrap acrylic while tweaking the SCP warning label geometry showed only a few work well at such a small scale:

SCP Earrings – einsteins

The mirror in the lower right got cut from the back side, making it the mmmm mirror image of the others.

IMO these would look and cut better in 1.5 mm acrylic, but it seems edge-lit acrylic only comes in 3 mm sheets.

They are absurdly fragile across the waist, but my admittedly limited exposure to fine jewelry suggests durability ranks low in the selection checklist.

2023-06-21