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: Gardening

Growing and sometimes fixing

  • Seedling Starter Pot Bottoms

    Seedling Starter Pot Bottoms

    One of Mary’s gardening compadres teaches a kid’s class which involves starting seedlings in “pots” made from the cardboard tubes found in paper towels and toilet paper. Cutting four slits in the bottom of the tube and folding the flaps inward puts a bottom on the pot, but what’s the fun in that?

    Draw a 42 mm circle, set the layer to cut corrugated cardboard, turn the circle into suitable arrays, flatten some boxes from the heap, and Fire the Laser:

    Seedling starter pot bottoms
    Seedling starter pot bottoms

    Collect the fallen disks from the chip tray and jam one in place as a serving suggestion, where it fits like it was custom-made:

    TP roll seedling starter pot bottom
    TP roll seedling starter pot bottom

    You’d still want to fold some flaps over the disk to keep it in place, but now your pot has a real bottom.

    I have no idea if 42 mm is a Galactic Constant, but it worked for the pile of tubes we had on hand.

    That was easy …

  • Engraved Popsicle Sticks

    Engraved Popsicle Sticks

    Having found a handful of popsicle sticks on my desk, I had to finish this up:

    Popsicle stick markers - engraving
    Popsicle stick markers – engraving

    The fixture has the same layout as the craft stick version, sized to fit the smaller sticks. They’re a bit thicker than the chipboard sheet, but match up well enough for the purpose.

    Even though the sticks don’t have much room for cutout letters, I had to try it anyway:

    Popsicle stick markers - finished
    Popsicle stick markers – finished

    Aligning the template to the fixture uses LightBurn’s Print-and-Cut tool, which seems easier than nailing the fixture to the laser platform.

    I suppose if they ever make actual popsicles with wood handles, they can tell who gets which one.

    For whatever it’s worth, the larger craft stick markers in the garden remain in good shape.

  • Craft Stick Plant Markers: Print-and-Cut Alignment

    Craft Stick Plant Markers: Print-and-Cut Alignment

    With the text laid out in the template, start LightBurn’s Print-and-Cut Wizard to align the template with the fixture on the laser platform.

    Jog the laser to the upper-right target on the fixture, click the upper-right target in the template, and tell P-n-C that’s the First Target. Jog to the lower-left target, click the lower left target, and that’s the Second P-n-C Target:

    Craft Stick Markers - fixture target detail
    Craft Stick Markers – fixture target detail

    The colored circles indicate the targets on the template:

    Craft Stick Markers - LB PnC layout
    Craft Stick Markers – LB PnC layout

    Select the Align No Scaling option, because the template and the fixture are exactly the same size.

    Click-n-drag to select the entire template (because you should always use Cut Selected Graphics), then frame it Just To Be Sure. The red dot pointer (or whatever you use) should kiss the fixture’s perimeter all the way around.

    Make sure the fill layer happens before the cut layer, then Release The Laser:

    Craft Stick Markers - engraving
    Craft Stick Markers – engraving

    The cut layer trims around the engraved letters to leave them standing in the rectangle:

    Craft Stick Markers - cutting
    Craft Stick Markers – cutting

    Some of the smaller bits won’t fall out as they’re cut, but a sharp thwack ejects them easily enough.

    Producing a set of ten sticks takes maybe seven minutes:

    Craft Stick Markers - fixture second fill
    Craft Stick Markers – fixture second fill

    Because craft sticks aren’t intended for fine woodworking, don’t expect consistent engraving results:

    Craft Stick Markers - wood engraving difference
    Craft Stick Markers – wood engraving difference

    Applying a finish would definitely improve their appearance, but most such chemicals don’t belong in an organic vegetable garden.

    I poked the first few test sticks along the edge of the herb garden:

    Craft Stick Markers - test sticks installed
    Craft Stick Markers – test sticks installed

    The rest will be deployed as their eponymous plants go in, then we’ll see how long they survive out there in the real world.

    They’re kinda cute and definitely improved my fixture / template skillz.

  • Craft Stick Plant Markers: Layout Template and Text Alignment

    Craft Stick Plant Markers: Layout Template and Text Alignment

    Putting the entire fixture layout onto a tool layer produces a template to align the text on the sticks:

    Craft Stick Plant Markers - fixture layout
    Craft Stick Plant Markers – fixture layout

    The rectangles mark where you put cut layer rectangles around the text in each stick. The sticks are 18 mm wide, so a 10 mm cutout leaves what should be enough wood along the edges. The rectangle length is a serving suggestion, as you must adjust the cut rectangle to fit the text.

    Group everything except the four targets into a single object so you won’t inadvertently move only a part of it. The targets must remain separate to work with the Print-and-Cut alignment. With that set up, Lock the position of the entire layout to prevent you from moving any part of it.

    Starting with a blank tag in the template:

    Craft Stick Markers - LB template - base
    Craft Stick Markers – LB template – base

    Draw a rectangle in a cut layer to match the template, which is easy if you have Object Snap set up properly:

    Craft Stick Markers - LB template - rectangle
    Craft Stick Markers – LB template – rectangle

    Add your text in a chunky font like Fira Sans Condensed Heavy, set to 15 mm tall with 5 mm horizontal spacing:

    Craft Stick Markers - LB template - lowercase text
    Craft Stick Markers – LB template – lowercase text

    LightBurn aggressively snaps a new text cursor to the nearest pre-existing text, so you may be forced to click far away from where you want to place the text, type the text, then move the finished string. LightBurn will also snap the text to the display grid as you drag it around, so hold the Ctrl key down to disable snapping while you eyeball the proper alignment with the rectangle. Leave about 2 mm between the left edge of the rectangle and the first letter to make an easily visible space.

    Although you can use lowercase letters, uppercase letters have the compelling advantage of being attached both top and bottom, so retype the text if you forgot about the Caps Lock key:

    Craft Stick Markers - LB template - uppercase aligned
    Craft Stick Markers – LB template – uppercase aligned

    The 15 mm font height I’m using seems to be the overall maximum from the top of the tallest letter to the bottom of the lowest descender, not the height of any specific capital letter, all of which extend beyond the cut rectangle by about half a millimeter. That’s crucial to make this thing work, so tune the font and its height appropriately.

    Select the text string when you have it properly aligned:

    Craft Stick Markers - LB template - text selected
    Craft Stick Markers – LB template – text selected

    Hit Ctrl-D to duplicate the text, tap the ↑ (Up) arrow key to move the copy out of the way, and set it to the fill layer.

    Now the magic happens.

    Select the rectangle, Shift-select the text, and Boolean Subtract (Alt minus) the text from the rectangle:

    Craft Stick Markers - LB template - subtracted text
    Craft Stick Markers – LB template – subtracted text

    Realize that you have screwed up by not shortening the right side of the rectangle to leave about 2 mm of open space. Bang on Ctrl-Z to undo the last step, shorten the rectangle, Shift-select the text again, then subtract the text from the rectangle:

    Craft Stick Markers - LB template - properly subtracted text
    Craft Stick Markers – LB template – properly subtracted text

    Select the filled copy and whack the ↓ (Down) arrow key to move it back over the cut layer:

    Craft Stick Markers - LB template - overlaid text
    Craft Stick Markers – LB template – overlaid text

    Now the filled layer will toast the characters to a nice brown and the cut layer will remove the background rectangle.

    After finishing the text dance for all the markers, the template should look something like this:

    Craft Stick Markers - LB PnC layout
    Craft Stick Markers – LB PnC layout

    The cheerful circles come from LightBurn’s Print-and-Cut Wizard aligning the template with the fixture holding the craft sticks on the laser platform, about which more tomorrow.

  • Craft Stick Plant Markers: Laser Fixture

    Craft Stick Plant Markers: Laser Fixture

    Converting craft sticks into plant markers should be a mass-production process, which means a fixture is in order:

    Craft Stick Markers - fixture first fill
    Craft Stick Markers – fixture first fill

    Admittedly, making ten markers at once barely qualifies as “mass production”, but you (well, I) can think of it a proof of concept.

    The basic shape comes from a 0.25 mm outset around the measured size of a craft stick (150×18 mm), plus an alignment target:

    Craft Stick Plant Markers - fixture cut layout - array base
    Craft Stick Plant Markers – fixture cut layout – array base

    A good rule of thumb says never do any more work than absolutely necessary, so the rest of the fixture comes from linear arrays replicating the stick slots and targets:

    Craft Stick Plant Markers - fixture cut layout - full
    Craft Stick Plant Markers – fixture cut layout – full

    The two strips over on the left (with a common cut down the middle) get glued to the underside of the fixture:

    Craft Stick Markers - fixture rail gluing
    Craft Stick Markers – fixture rail gluing

    They’re exactly 5 mm apart to bracket one of the knife-edge bars supporting the fixture. The bar is upside-down to put its flat side upward:

    Craft Stick Markers - fixture target detail
    Craft Stick Markers – fixture target detail

    Yes, the fixture is made of chipboard, mostly because it’s about the same thickness as a craft stick and it’s cheap & readily available. Each target gets an ink blot to make it more conspicuous; there is also a tiny hole burned through the chipboard at the center to mark the other side for the strips.

    Two knife-edge bars (sharp side up) support the sticks near their ends, well out of the cutting path, to prevent scorch marks:

    Craft Stick Markers - fixture overview
    Craft Stick Markers – fixture overview

    It’s worth noting the knife-edge bars are 5 mm wide and the platform spaces them on 3/8 inch = 9.525 mm centers. Not 10 mm, not 9.5 mm, exactly 3/8 inch. Kinda like the platform leadscrews: a 4 mm lead thread driven by a belt with 0.2 inch pitch. Only in America.

    This doodle captures the key dimensions down there in the corner to work out where the strips should go:

    Craft Stick Plant Markers - fixture vs laser bar spacing doodle
    Craft Stick Plant Markers – fixture vs laser bar spacing doodle

    Now, to convert names from a garden map into plant markers …

  • Plant Markers: Craft Stick Edition

    Plant Markers: Craft Stick Edition

    Inspired by a LightBurn forum post I can no longer find once again tracked down, I tried my hand at popsicle craft stick plant markers:

    Plant Markers - craft stick tests
    Plant Markers – craft stick tests

    You’d have only one name on the end of each stick, with the uncut section jammed into the ground: these are test pieces to demonstrate capability.

    Wood is better than acrylic because it checks all the eco-friendly attribute boxes. Admittedly, craft sticks don’t exactly grow on trees, but we seem to ignore such externalities in nominally eco-friendly products.

    Bonus: a recurring revenue stream from the replacement market!

    The design, such as it is, involves subtracting the letters from a rectangle maybe half a millimeter short of their top & bottom extents and a few millimeters longer than their length. Using a chonky font with generous letter spacing may prevent prompt disintegration by weathering:

    Plant Marker - craft sticks - LB layout
    Plant Marker – craft sticks – LB layout

    Engraving the letters marks their uncut sections outside the rectangle, although we know laser char on wood-ish materials fades in sunlight. The two big sticks have Radish engraved with varying density; the darker version looks better against a lighter background never found in an actual garden.

    Mary thinks they might be a nice fundraiser for the next Master Gardener Plant Sale.

    Outdoor field tests seem appropriate …

  • Please Close The Gate Signs: MDF Weathering

    Please Close The Gate Signs: MDF Weathering

    With the new signs in place, the old ones paused briefly for a photo op on their way to the trash:

    Please Close The Gate - weathered MDF
    Please Close The Gate – weathered MDF

    That’s eight months of weathering on MDF covered with indoor urethane sealant and it’s not as awful as I expected: the MDF didn’t actually disintegrate, it just collected some mold / mildew / crud.

    A closer look:

    Please Close The Gate - weathered MDF - detail
    Please Close The Gate – weathered MDF – detail

    The black paint survived surprisingly well.

    I hadn’t paid much any attention to the edges, so they got covered with random amounts of black paint and urethane. It seems that’s where the disintegration starts:

    Please Close The Gate - weathered MDF - side view
    Please Close The Gate – weathered MDF – side view

    MDF definitely isn’t the right material for an outdoor sign and I knew that going in, but it’s cheap and readily available, which makes up for a lot.

    For comparison, they looked nice right after installation:

    Please Close The Gate - fresh painted
    Please Close The Gate – fresh painted

    Ya learn something new every year around here!