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

  • Punched Cards: Layout Alignment

    Punched Cards: Layout Alignment

    My initial process of picking punched cards from the top of the stack, taping them together, then cutting a layer of the eagle produced unpredictable results when there weren’t enough holes to be interesting or a card joint appeared in a conspicuous spot:

    Apollo 11 Eagle patch - layer test - tail
    Apollo 11 Eagle patch – layer test – tail

    I now arrange the SVG image of the card’s holes for best effect on each eagle layer:

    Apollo Eagle - V4 Layer 7 card layout
    Apollo Eagle – V4 Layer 7 card layout

    The small squares near the corners of the image appear on every layer to properly register all the eagle outlines.

    Mirroring the layout produces the hole pattern as seen from the back side of the cards, where the tape is applied:

    Apollo Eagle - V4 Layer 7 card layout - mirrored
    Apollo Eagle – V4 Layer 7 card layout – mirrored

    Then it’s (relatively) easy to align the cards while muttering “the rightmost hole in the lower sequence number is just about aligned with the upper card edge, which puts the middle-ish hole in the group of four in the 9 row over the left hole of those two” and so on and so forth. Cut off a strip of tape, carefully lay it along the joint between the cards, and add them to the outgoing pile.

    The top two layers are cut with the back = unprinted = blank side of the card upward to produce the eagle’s white head, with the outlines strategically located to avoid shredding the feathers with holes:

    Apollo Eagle - V4 Layer 8-9 card layout
    Apollo Eagle – V4 Layer 8-9 card layout

    The value of this process becomes more apparent for the nine cards making up the bottom layer:

    Apollo Eagle - V4 Layer 1 cards
    Apollo Eagle – V4 Layer 1 cards

    Most of the white tail comes from the reversed card in the bottom row, inset into the two cards above it. The next layer covers those sections of the legs and olive branch, which is easy to confirm by aligning the layers using their border squares.

    The layout mirrored for easier taping:

    Apollo Eagle - V4 Layer 1 cards - mirrored
    Apollo Eagle – V4 Layer 1 cards – mirrored

    This is from a previous layout, but the improvement is obvious:

    Apollo Eagle - V3 - tail
    Apollo Eagle – V3 – tail

    The trick with all this is to select only the eagle outline for cutting amid all the card details. Although putting the cards on a tool layer would avoid that problem, the holes are much less visible and they’re pretty much the entire point of this process.

    Aligning the taped cards on the platform with the to-be-cut outline follows much the same process as aligning the printed cards for punching:

    • Select the cards and the eagle outline
    • Snap to the middle of the LightBurn workspace with the P key
    • Focus the laser on the cards if you haven’t already done so
    • Move the laser head to one of the card bevels using Ctrl-L and clicking on one end of the bevel
    • Skootch the cards to put that bevel at the red dot pointer location under the laser head
    • Move the laser head to another bevel
    • Skootch the cards as needed
    • Iterate until satisfied
    • Fire The Laser

    Although each card layout has the four targets used to cut it from the printed card stock, those targets no longer exist on the cards because they’ve been cut off.

    You could use Print and Cut to align the LightBurn workspace to the cards, but it’s easier and faster to just skootch the cards around.

    Actually cutting the outline takes a few seconds and is kinda anticlimactic after all that setup.

  • Punched Cards: Layered Apollo Eagle V3

    Punched Cards: Layered Apollo Eagle V3

    Fixing some of the outstanding issues produces another Apollo Eagle from layers of punched cards:

    Apollo Eagle - V3 - overview
    Apollo Eagle – V3 – overview

    Stipulated: nobody ever ran punched cards through a multi-color printing process. A posterized version of the Apollo 11 mission patch eagle just seemed appropriate for cards containing a chunk of the mission source code.

    Putting the tail feathers on two layers of reversed cards definitely improved the outcome:

    Apollo Eagle - V3 - tail
    Apollo Eagle – V3 – tail

    The lines across two of the tail feathers come from inadvertently printing a quilting pattern intended for Letter paper after setting up a stack of 1/3 Letter blanks. Trust me on this: you do not discard any salvageable blooper cards.

    The wing feathers get more definition and have sculptured upper layers:

    Apollo Eagle - V3 - wing
    Apollo Eagle – V3 – wing

    The olive branch improved with fewer layers and contouring the claws makes them less chunky:

    Apollo Eagle - V3 - olive branch
    Apollo Eagle – V3 – olive branch

    The beak and head now have slight contouring, with the neck feathers standing out nicely over the logo below:

    Apollo Eagle - V3 - head
    Apollo Eagle – V3 – head

    Although this is the third almost-ready version, it rests on the wings of many previous attempts:

    Apollo Eagle - layered trials
    Apollo Eagle – layered trials

    The card joints on successive layers are now farther apart, although the long run across the middle of the body stands out more than I expected. The small pieces of cards at the top of the wings need more contrast.

  • Punched Cards: Apollo Eagle Card Layout

    Punched Cards: Apollo Eagle Card Layout

    With some lessons learned from the first pass, the bottom layer of the Apollo Eagle gets a reversed card for the white tail feathers:

    Apollo Eagle - Layer 1 card layout
    Apollo Eagle – Layer 1 card layout

    Which looks like this just after cutting the outline:

    Apollo Eagle - Layer 1 as cut
    Apollo Eagle – Layer 1 as cut

    Gently removing the scrap from the edges reveals the eagle:

    Apollo Eagle - Layer 1 cutout
    Apollo Eagle – Layer 1 cutout

    The top two layers also come from a reversed card, with those shapes arranged to put the holes in attractive places:

    Apollo Eagle - Layer 7 8 card layout
    Apollo Eagle – Layer 7 8 card layout

    The five layers in between as a slide show:

    • Apollo Eagle - Layer 2 card layout
    • Apollo Eagle - Layer 3 card layout
    • Apollo Eagle - Layer 4 card layout
    • Apollo Eagle - Layer 5 card layout
    • Apollo Eagle - Layer 6 card layout

    It took a while to get over cutting up all those nice cards.

    Some deft glue stick work produces a layered eagle:

    Apollo Eagle - assembly overview
    Apollo Eagle – assembly overview

    I managed to get a dark bottom in the nostril, which turned out weird:

    Apollo Eagle - head detail
    Apollo Eagle – head detail

    All in all, though:

    • Fewer layers are better
    • The head came out OK-ish
    • The bottom layer card arrangement is too fussy
    • The olive branches still look weird
    • The claws are still ugly
    • The tail needs more contrast, perhaps two layers
    • Having horizontal card splices aligned on successive layers is bad

    More study is definitely in order …

  • Punched Cards: Paper Matters

    Punched Cards: Paper Matters

    Using different card colors makes it easy to find your program deck in the Comp Center’s output bins:

    Punched Cards - paper color vs smoke stains
    Punched Cards – paper color vs smoke stains

    The smoke stains on the bottom orange card came from the same LightBurn settings used with the purple (violet?) and blue (teal?) cards: 400 mm/s, 35% power, and assist air enabled.

    The conventional wisdom is that you *do not* use assist air while engraving, to avoid pushing the smoke / soot down onto the material, and I’ve generally followed that rule. Apparently evaporating holes in the other colors doesn’t generate much smoke and I had no reason to notice the air was enabled.

    The upper orange card differs from the lower one only in having the assist air turned off, so I have definitely learned my lesson!

    Readers of long memory will recall the dual-path assist air setup that pushes 2 l/m through the nozzle when the LightBurn layer has AIR disabled, specifically to keep smoke out of the nozzle and away from the lens; that gentle breeze doesn’t push smoke into the paper.

    FWIW, that’s why I run a set of test cards before I do anything fancy for the first time.

  • Punched Cards: Layered Apollo Eagle

    Punched Cards: Layered Apollo Eagle

    What with punching the Apollo 11 CSM source code into the cards, converting the mission’s eagle into a layered shape made some sense.

    The original Apollo 11 mission patch:

    Apollo 11 mission patch - rescaled
    Apollo 11 mission patch – rescaled

    After considerable faffing, a few of the fifteen layers look like this in GIMP:

    Apollo 11 Patch - eagle layers
    Apollo 11 Patch – eagle layers

    Each layer is a connected white region defining the cut perimeter, which will expose some part of the layer(s) below it in the stack. The small squares in the corners provide a bounding box to make all the layers snap to the same location.

    Then:

    • Select each layer’s shape + corner boxes with GIMP’s Color Select tool
    • Convert the selection to a path
    • Export paths as SVG files (all fifteen of them!)
    • Import SVGs into LightBurn & arrange neatly
    • Put outlines on a cut layer, corner squares on a tool layer
    • Burn each layer separately

    Testing the concept with packing paper looked surprisingly good:

    Apollo 11 Eagle - layer test piece
    Apollo 11 Eagle – layer test piece

    A few key layers on punched cards:

    Apollo 11 Eagle - card partial test piece
    Apollo 11 Eagle – card partial test piece

    The changes for each of those iterations required tweaking the original layer images to eliminate obvious-in-retrospect problems, recreating the SVG files, and importing into LightBurn. This is a relentlessly manual process.

    Then I ran a full-up test of all fifteen layers on cards punched with the Apollo source code.

    Cutting the head layers from face-down cards made them sufficiently white, although it’d be nice to have a different beak color and darker eyes :

    Apollo 11 Eagle patch - layer test - head
    Apollo 11 Eagle patch – layer test – head

    I must arrange the cards with text to put more holes in the wings, although too many will cause fragile feathers:

    Apollo 11 Eagle patch - layer test - wing
    Apollo 11 Eagle patch – layer test – wing

    The white tail should be also done with face-down cards, more holes, and the three-way joint between the cards shifted under the tail layers to its left:

    Apollo 11 Eagle patch - layer test - tail
    Apollo 11 Eagle patch – layer test – tail

    The feet and olive branch were a total faceplant, as successive layers did not register accurately enough to overlay the leaves:

    Apollo 11 Eagle patch - layer test - feet
    Apollo 11 Eagle patch – layer test – feet

    Not to mention those ug-u-lee claws.

    The wing layers need more rounding along their edges, perhaps with some thin cuts to emphasize the feathers.

    On the whole, though, I think it turned out well.

    Things to do:

    • Registration holes / pins up to the top layer
    • Remove speckles on all the layers
    • Arrange cards for more hole density where needed
    • Better glue application
    • Different card colors?

  • Punched Cards: Almost Automated Punching

    Punched Cards: Almost Automated Punching

    With a printed card in a fixture and aligned to the punch pattern, all that’s left is to Fire The Laser:

    Punched cards - laser fixture - cut
    Punched cards – laser fixture – cut

    When the card drops free, then:

    1. Remove card from fixture
    2. Insert next card
    3. Import next SVG file
    4. Verify alignment
    5. Fire The Laser

    The gotcha lies in Step 3, which requires mousing & clicking through a tedious file selection dialog. For whatever reason, Windows / LightBurn does not remember your place in the file directory, so you must not only remember which card you just punched, but maneuver to the next card in the sequence.

    It turns out there exists a lightly documented SendUDP.exe command-line program to send a file to the running LightBurn instance, which will (in the case of an SVG file) import it and center the layout at the middle of the workspace.

    Which means a Windows batch file can feed SVG files, one at a time, in order, to LightBurn. Before importing the file, however, LightBurn verifies you want to blow away the previous layout:

    LightBurn - Confirm import
    LightBurn – Confirm import

    Tapping D lets the import proceed.

    The feed-lb.bat batch file:

    @echo off
    for %%f in (%1) do (
        echo Sending: %%f
        "c:\Program Files\LightBurn_Prerelease\sendudp" "%CD%\%%f"
        pause
    )
    echo Done!
    

    Because the SVG files have convenient sequential names, this does what’s needed:

    …snippage…>.\feed-lb.bat Cards\Tests\test-?-lb.svg
    Sending: Cards\Tests\test-1-lb.svg
    Press any key to continue . . .
    Sending: Cards\Tests\test-2-lb.svg
    Press any key to continue . . .
    

    Set up the process:

    1. Start LightBurn with the proper layer defaults
    2. Start a Command Prompt
    3. Get to the proper directory
    4. Run feed-lb.bat aimed at the SVG files
    5. Align the first card
    6. Click in LightBurn window
    7. Alt-S to start cutting

    When the cutting is done, the loop continues:

    1. Replace / align card
    2. Click the Command Prompt window
    3. Hit (almost) any key to send the next file
    4. Click the LightBurn window
    5. D to discard old layout / import next SVG
    6. Alt-S to start cutting
    7. Iterate

    Assuming you don’t spend too much time aligning a card, punching it can take up to four minutes. This process is definitely not competitive with an experienced operator on a real IBM 029 keypunch machine, but it’s as good as it gets in the Basement Shop.

    One wrinkle: The imported SVG file uses LightBurn layer colors, so the various shapes appear on those layers with their default speed / power cut settings. It’s your responsibility to make the cut setting defaults match the cardstock, because that’s the only way (short of per-card clicking) to make it happen.

    Another wrinkle: the Command Prompt window opens at your Windows home directory, thus requiring a little setdir.bat file in there to get you where you want to go:

    @echo off
    z:
    cd "\Project Files\Laser Cutter\Punched Cards\Programs\"
    dir
    

    Now it’s just a matter of punching and stacking cards:

    Punched cards - storage trays
    Punched cards – storage trays

    It’ll take a while before I’m ready for the next step …

  • Punched Cards: Print vs. Punch Alignment

    Punched Cards: Print vs. Punch Alignment

    The printed card layout has targets in all four corners:

    Test Card 3 - unpunched
    Test Card 3 – unpunched

    Which are at exactly the same positions as the targets in the punched card layout, because they come from the same source code:

    Punched Cards - laser SVG layout
    Punched Cards – laser SVG layout

    The alignment problem has several parts:

    • The 1/3 Letter sheets aren’t exactly (11 inch)/3 tall, because neither the paper cutter nor my cutting hand have any particular accuracy
    • The printer’s feed rollers don’t maintain the sheet’s angular or positional alignment as it travels through the printer
    • A fractional-millimeter misalignment between the printed characters and the evaporated holes is obvious
    • Performing an intricate alignment dance on each card guarantees at least an occasional misstep

    I initially thought “Well, of course, I’ll just use LightBurn’s Print and Cut tool to match them up.” After some fumbling around, PnC is entirely too heavyweight for the problem at hand and a much simpler / faster / easier technique works better.

    It turns out LightBurn imports SVG files centered on the layout grid representing the laser platform:

    LightBurn - imported SVG layout
    LightBurn – imported SVG layout

    So putting the card fixture dead-center on the platform lines them up pretty closely:

    Punched cards - laser fixture overview
    Punched cards – laser fixture overview

    After importing an SVG, use Move Laser to Selection to put it in the middle of the upper right target, then create a Saved Position imaginatively called UR:

    LightBurn - Move window UR position
    LightBurn – Move window UR position

    Repeat for the lower left target to create the LL position.

    Because the targets are on 200×80 mm centers and the middle of the platform is at (350,250), the target positions will be nice round numbers:

    • UR = (250,210)
    • LL = (450,290)

    Yes, the coordinates run backwards, because that’s how Ruida controllers deal with a home position in the rear right corner of the platform.

    You define those positions once, because all the cards are the same size and end up in the same location on the platform.

    Although I expected to slide the cards under the fixture’s retaining lip from the front, it turns out an easier way is:

    • Gently buckle the card center upward
    • Align it against the rear edge
    • Slide the left edge under its lip
    • Lower the center while sliding the right edge under its lip
    • Tuck the card under the rear lip
    • Verify the front edge aligns with the marked lines, which means it’s properly in the fixture

    The magnets hold the fixture against the honeycomb:

    Punched cards - laser fixture alignment
    Punched cards – laser fixture alignment

    The fixture can still slide with firm finger pressure and the card can move a little bit within the fixture. Note that leaning on the honeycomb will press it (and the fixture) downward enough to put the dot at a slightly different position; if you align while leaning, recheck the dot’s position after you unlean.

    Move the laser to the UR position and skooch the fixture to align the upper right target to the red dot:

    Red dot vs printed target alignment
    Red dot vs printed target alignment

    The blue lines are nominally 0.2 mm wide and actually about 0.3 mm wide, so the red dot is 0.3 mm diameter. If your red dot is larger, better focus and a polarizing filter will help.

    I periodically fire a test pulse to verify the red dot matches the actual laser beam position:

    Red dot vs printed target vs laser spot alignment
    Red dot vs printed target vs laser spot alignment

    That slight mismatch adds to the overall positioning error.

    Repeat for the LL target, recheck UR to make sure it didn’t move, iterate as needed.

    The printed card is now aligned to the hole pattern about to be burned into it.

    Although this sounds like a lot of faffing, it goes surprisingly quickly because all the cards are Pretty Close™ to identical and the adjustments are very small. Although it’s possible to park the laser head at the UR position, I prefer to have it out of the way while unloading & loading the cards, then move it directly to UR to check the new card.

    Fire The Laser:

    Test Card 3 - punched
    Test Card 3 – punched

    I love it when a plan comes together:

    Test Card 3 - punched - detail
    Test Card 3 – punched – detail

    A dash of automation helps when doing more than one card, which, believe it or not, involves a Windows batch file …