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: Improvements

Making the world a better place, one piece at a time

  • Sears / Kenmore Vacuum: Design Tweakage

    Sears / Kenmore Vacuum: Design Tweakage

    Despite cogent reasons for not buying another Sears vacuum cleaner, the brand currently represents a local maximum of the desirability curve: cheap, readily available, works well enough, and, surprisingly, bags for the defunct Progressive (whatever that meant) vacuum seem to fit just fine.

    But the new one does come with some annoyances, starting with trendy dark gray engraved / molded control markings:

    Sears Vacuum - power and cord controls
    Sears Vacuum – power and cord controls

    Quick: from the other end of the vacuum hose, which one must you stomp to turn it off?

    Well, I can fix that:

    Sears Vacuum - marked power switch
    Sears Vacuum – marked power switch

    After the Progressive’s bizarre and overly complex tool fittings, the new unit has tools that slip-fit onto a classic steel tube, which means I can throw all those adapters into a box of 3D printing examples for use in the unlikely event I ever do another show-n-tell presentation.

    It also has a simple rotating suction control ring at the handle:

    Sears Vacuum - marked suction vent control
    Sears Vacuum – marked suction vent control

    Which, as you can tell from the fluorescent tape, featured the same embossed and unreadably small dark gray markings.

    Because that ring and its glaring tape is invisible from the user’s end of the handle, I eventually duct-taped the ring in position to prevent another inadvertent loss-of-suction accident.

    If we ever need reduced suction on a regular basis, I’ll conjure a better ring from the vasty digital deep:

    Sears Vacuum - suction vent doodle
    Sears Vacuum – suction vent doodle

    I obviously no longer form deep emotional attachments to these things …

  • Seasonal Snowflake Coasters

    Seasonal Snowflake Coasters

    The rattlecan chipboard coasters having passed their Best Used By dates, I figured a more durable seasonal version was in order:

    Snowflake Coasters - overview
    Snowflake Coasters – overview

    I laid out the design with the intent of cutting an acrylic snowflake with a bit of compensation to fit snugly into a plywood background:

    Snowflake Coaster - LB layout
    Snowflake Coaster – LB layout

    At the last moment I realized I could just cut two of the patterns on the left, swap the snowflakes, and get two coasters with very little scrap:

    Snowflake Coasters - detail
    Snowflake Coasters – detail

    Mary thinks the gap between the snowflake and the background looks OK. I’m not convinced, but studying the results suggests applying enough kerf compensation to close the largest gaps would results in the rest of the flake not fitting into its socket. Plus, of course, you’d have more scrap.

    Embiggening the small dagger-shaped pieces around the center would be an improvement. Perhaps cutting those as a separate operation after arranging them in a corner would work.

    Protip: Align the grain in those daggers with the rest of the plywood, because It Will Be Very Obvious if you don’t.

    Applying a nice wood stain / finish to the plywood, perhaps before cutting it out, would certainly improve the result.

    Invisible on the bottom: self-adhesive cork disks eliminating the need to glue the pieces to something else. I had thought of a blank plywood or MDF disk, but came to my senses just in time.

    The original SVG fell with a blizzard from one of the many SVG snowflake generators out there. Because LightBurn uses only the stroke centerlines of SVG images and ignores the stroke width, it required some tweakage before becoming a coaster.

    After saving an SVG flake from the blizzard, fire up Inkscape:

    • Import the SVG file
    • Center it in whatever page you’re using
    • Ungroup the flake from the frame (if it has one)
    • Delete the frame to leave only the flake
    • Select the flake
    • Invoke Path → Stroke to Path
    • Save as an SVG image under a new file name

    Then fire up LightBurn:

    • Import the tweaked SVG file
    • Assign a layer with line (rather than fill) parameters
    • Ungroup to separate the flake’s strokes
    • Weld the strokes together to remove the overlaps
    • Wrap a coaster outline around it
    • Resize the flake as needed
    • Set layer parameters as needed
    • Duplicate the flake
    • Embiggen as needed
    • Unleash the laser!

    The LightBurn SVG layout as a GitHub Gist:

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  • Splined Neck Cozy Pattern

    Splined Neck Cozy Pattern

    Mary made a neck cozy based on a Craftsy description using a pattern I’d extracted from the low-res photo and rescaled to the proper size. The perimeter came out grittier than I like, but the laser had no trouble chopping it from a sheet of paper, and she cut smoothly around the lumps:

    Neck Cozy mask - right
    Neck Cozy mask – right

    It looks better on her, but you get the general idea:

    Neck Cozy - rev 1 finished
    Neck Cozy – rev 1 finished

    After some experience, however, she wanted to lengthen the top and bottom seams to improve the way it draped, which meant I had to modify the extracted pattern. The original pattern in the Craftsy photo was hand-drawn (which is perfectly fine) and the two halves were of two different sizes; we decided to work with the left half and produce a symmetric result.

    Rather than fiddle with the bitmap, I drew a rectangle around the outside of the left pattern mask, converted it to a path, moved the nodes to key locations, then fiddled with the control points to lay the splines along the perimeter:

    Neck Cozy pattern - LB splines
    Neck Cozy pattern – LB splines

    Removing the bitmap makes the splines much more obvious and shows the much smoother perimeter:

    Neck Cozy pattern - LB extended splines
    Neck Cozy pattern – LB extended splines

    Adding a few nodes to change the splined shape is much simpler than fiddling with the bitmap, particularly when tweaking their position as directed by someone who knows how the fabric will eventually take shape.

    Add fiducial marks and a label, duplicate the shape, mirror it to get the other half, and fire the laser:

    Neck Cozy pattern - as cut right
    Neck Cozy pattern – as cut right

    Fabric cutting isn’t in my wheelhouse, but I made the offer …

    The LightBurn layout as a GitHub Gist:

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  • More Laser-Cut Shop Wipes

    More Laser-Cut Shop Wipes

    A filled box of worn-out clothing produced more shop wipes:

    Laser-cut Shop Wipes - assortment
    Laser-cut Shop Wipes – assortment

    The last few pieces were a bit finicky, but provided good on-the-fly practice with linear arrays:

    Shop Wipe - LightBurn setup
    Shop Wipe – LightBurn setup

    This trick never grows old:

    Laser-cut Shop Wipes - as-cut
    Laser-cut Shop Wipes – as-cut

    I washed those neat stacks (in their very own load!), which didn’t turn out well:

    Laser-cut Shop Wipes - washed
    Laser-cut Shop Wipes – washed

    They’ll get used no matter what they look like!

  • Ed’s Fireball Cocoa: Magnetic Stirring

    Ed’s Fireball Cocoa: Magnetic Stirring

    An addition to my morning cocoa makes it mmmm turn out better:

    Cocoa magnetic stirring - magnet
    Cocoa magnetic stirring – magnet

    Start with an ounce of milk, dump in the rest of the ingredients, spin up the stirrer, and slowly add the 8 oz of milk that just reached the end of its 70 seconds in the microwave:

    Cocoa magnetic stirring - vortex
    Cocoa magnetic stirring – vortex

    The green LED to the left of the speed knob runs from the PWM signal driving the motor, so it flickers visibly and interacts with the camera shutter.

    Let it whir for a few minutes until all the cocoa bombs vanish and it’s ready for another 33 seconds in the microwave.

    The most recent batch of cocoa arrived in an exceedingly vacuum-packed mylar bag, to the extent the bag resembled a brick and the solid cocoa within fractured into big chunks. Bashing the chunks with a fork got tedious enough to remind me of the stirrer I got to mix titanium dioxide for the yet-to-be-tried glass engraving.

    Back in the day, the teflon shell molded on the magnet had a rib around its middle to make it pivot neatly on a point contact. This one is flat and dislikes spinning on the slightly concave cup bottom.

    Protip: fish the stirrer out before sipping the cocoa, lest it become a tiny cow magnet.

  • Lip Balm Holder, Laser Cut Edition

    Lip Balm Holder, Laser Cut Edition

    Loading the bike batteries into the Rolltop Cupcake Box reminded me I hadn’t updated the Lip Balm Holder around the latest tube of sunscreen. My excuse was I didn’t quite know how to model the not-quite-elliptical shape of the Coppertone sunscreeen tube in OpenSCAD, but now I can bypass that whole problem:

    Lip Balm Holder - installed
    Lip Balm Holder – installed

    The trick is to scan the bottom of the cap to get a high-contrast image:

    Coppertone Sport Tube - lid scan
    Coppertone Sport Tube – lid scan

    Import the image into LightBurn, draw a circle tangent to the outside of the cap’s smaller diameter, turn the circle into a path, drag the nodes and twiddle the control points to create a symmetric shape just outside the cap, then outset the result by 1.5 mm for clearance around the tube:

    Coppertone Sport Tube - LB splines
    Coppertone Sport Tube – LB splines

    That 3 mm of wiggle room lets us drop the tube into its socket without careful alignment.

    The lip balm tubes all fit into 18 mm circles requiring no special design skillz:

    Lip Balm Holder - LB layout
    Lip Balm Holder – LB layout

    The mid-left oval goes around the Coppertone tube.

    The top-mid drawing shows the 3 mm outset around each of the pieces, with the smaller tubes arranged to put their midlines tangent to each other and the oval tube. LightBurn does not, as far as I can tell, have a direct way to align a shape tangent to two other shapes at the same time, but iterating at increasingly absurd zoom levels gets the job done fairly quickly.

    Welding those shapes together produces the top-right drawing, which serves as the template for the lower set of layers.

    Deleting the inner details produces the mid-right blob for the bottom layer.

    Most of the layers come from 3 mm plywood, with edge-lit acrylic on the top and bottom surfaces:

    Lip Balm Holder - side view
    Lip Balm Holder – side view

    Mary pronounced it better looking than the 3D printed version, which I agree clears a rather low bar, but it suffices for the job.

    The LightBurn layout as a GitHub Gist:

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  • Laser Cutter: Fire Extinguisher Brackets

    Laser Cutter: Fire Extinguisher Brackets

    A Genuine Kidde Fyre Freez CO₂ extinguisher that Came With The House™ finally found its ideal location:

    Fyre Freez extinguisher - mounted
    Fyre Freez extinguisher – mounted

    It was last refilled 65 years ago:

    Fire Extinguisher Recharge Tag - 1957
    Fire Extinguisher Recharge Tag – 1957

    I know it’s still good, because the label has its 4 lb 7 oz refilled gross weight stamped into it, which is exactly what it weighs today.

    Walter Smith Welding Supplies may still be in business, perhaps in Poughkeepsie, but their former 18 Downs St location in Kingston has become Noble Gas Solutions:

    Noble Gas Solutions - 18 Downs St Kingston - 2019
    Noble Gas Solutions – 18 Downs St Kingston – 2019

    Back then, you could call Smith Welding at a four digit phone number in Kingston: 5061. Nowadays, you must call Noble Gas with three more digits: 338-5061. As Charles Stross observed, something like 70% of the future is already in place, because infrastructure is so tenacious.

    Heck, just look at that Quonset hut!

    Keep calm and extinguish on:

    Fyre Freez extinguisher - step 4
    Fyre Freez extinguisher – step 4

    Two thoughts spring to mind:

    • Most kitchen fires start waist-high (it’s the late 1950s: where else would she be?)
    • She’s gonna lose skin on that metal tank

    Seems to me a Fyre Freez will get cold enough to freeze skin while discharging, but I admit to not having actually tried it.

    Anyhow, given the overall basement decor, the brackets have the right general style:

    Fyre Freez extinguisher - bracket detail
    Fyre Freez extinguisher – bracket detail

    Here’s hoping its future will be as dull as its past …