LOPSY

Draw a Technical Cutaway Poster of a Pin-Tumbler Lock

Make a 1950s shop-manual cutaway poster of a lock in Lopsy, with pattern-fill section hatching, cloned pins, a rotated face view, callouts and a parts list.

  • Advanced
  • 120 min
  • 17 steps

Published

The finished poster on cream graph paper inside a double black border. The title reads LOCKED / OPEN in tall black condensed letters with an orange slash, over a tracked subtitle, Anatomy of the Pin-Tumbler Cylinder. Fig. 1 shows a hatched brass lock cylinder in section with no key. Five pin stacks of steel driver pins and brass key pins hang in their chambers under white springs, and an orange dashed shear line cuts through the driver pins. Fig. 2 shows the same cylinder with a silver key inserted. Its cuts lift every pin so the gaps line up on the shear line. Numbered balloons 1 to 8 point at the parts. At the bottom are two round face views, one with the keyway upright and one turned 30 degrees with an arrow, then a parts list with number, part, quantity and material columns and a three-cell title block.

Old shop manuals explained machines with cutaways. The part is sliced down the middle, the cut metal is hatched, and every piece gets a numbered balloon. It's a great format for a poster. Here you'll draw one of the best mechanisms to explain that way: the pin-tumbler lock, shown locked and then open.

The whole idea fits in one line: the plug only turns when every gap between a key pin and a driver pin sits on the shear line. So the poster shows two sections of the same lock:

  • Fig. 1, locked: with no key, the driver pins straddle the shear line.
  • Fig. 2, open: the right key lifts every gap onto it.

Everything is drawn from marquees, lassos and fills. There are no photos. Along the way you'll use:

  • Define Pattern and Fill with Pattern (for section hatching, a dashed line and grid paper)
  • the Magic Wand with Contiguous off
  • copy, paste in place, Move and Merge Down to clone parts
  • a ⌘-snapped rotate transform
  • the Stroke effect for ink outlines and leader halos
  • Grid and Snap, ruler guides and groups
  • two Google fonts: Bebas Neue and IBM Plex Mono

The palette is a period brass-and-steel one, with a single accent colour:

  • paper #EDE6D3
  • ink #1F1D1A
  • brass #C8973A (housing) and #DDB255 (plug)
  • cavity #2A2622
  • steel #6C757A / #A9B1B5 / #DCE2E4
  • safety orange #E4572E, used only for the shear line

  1. Set up a portrait sheet

    Create a 1500 × 2250 px document (a 2:3 poster) with a White background. Set the foreground to paper #EDE6D3, then choose Edit → Fill on Layer 1 and rename it Paper.

    The New Document dialog with Width 1500 and Height 2250 pixels and a White background

  2. Draw the hatch, dash and grid tiles

    Three repeating textures do most of the drafting work. Add a temporary layer called Tiles, zoom in to about 600% on an empty corner, and draw them with fills:

    • Housing hatch: a 32 × 32 square with 3 px ink lines at 45°, one every 16 px. Lasso each diagonal band and fill it. Where a band runs off the square, it has to come back in on the opposite edge, or the tiles won't meet.
    • Plug hatch: the same tile mirrored, with the lines leaning the other way. Adjacent parts in a section drawing are always hatched in opposite directions.
    • Dash: a 16 × 4 orange block inside a 24 × 4 marquee. The 8 px transparent tail becomes the gap.
    • Grid: a 24 × 24 square with a 1 px #9FB4BC line along its top and left edges.

    Marquee each tile exactly and choose Edit → Define Pattern. Then delete the Tiles layer.

    A zoomed-in view at 645% showing two 32 by 32 tiles of diagonal black lines (one leaning each way), a short orange dash and an L of blue-grey grid line, with a marquee around the first tile

  3. Tile the grid paper

    Add a layer called Grid above Paper. With nothing selected, choose Edit → Fill with Pattern…, pick the grid thumbnail and click Apply. Then finish the layer:

    1. Marquee (56, 56) → (1444, 2194), choose Select → Inverse, press Delete, then Cmd+D.
    2. Set the layer's Blend to Multiply (in the ✦ effects drawer).
    3. Set its opacity to 32%.
    The Pattern Fill dialog listing the four new patterns, with the 24 by 24 grid tile selected

  4. Add the border and margin guides

    On a Frame layer, draw two rules. For each one, fill a marquee, run Select → Shrink… and press Delete:

    • an outer rule from (40, 40) to (1460, 2210), shrunk by 6
    • an inner rule from (54, 54) to (1446, 2196), shrunk by 2

    Then click the rulers to drop guides:

    • vertical guides at x 110 and 1390 (the margins) and 750 (the centre)
    • horizontal guides at y 428 (under the title) and 1740 (above the bottom band)

    Everything in the poster stays between the two margin guides.

    The cream sheet with faint graph-paper lines, a thick outer and thin inner black border, and cyan guides at the left and right margins, the centre and two horizontal band lines

  5. Cut the housing and plug

    Click New Group and name it Fig 1 Locked. Build the section from the back forward, one layer per part:

    1. Cavity: lasso the whole cylinder outline and fill it with #2A2622. The outline is the housing, from (450, 596) to (1310, 1020) with 14 px chamfered corners, plus a front lip from (416, 760) to (450, 1036). Anything you cut out of the brass layers above will show this dark "air".
    2. Housing: fill the same outline in brass #C8973A. Delete the plug's space, (416, 796) → (1310, 996). Then delete five 56 px-wide pin chambers from the top edge down to y 796, centred on x 580, 720, 860, 1000 and 1140.
    3. Plug: fill (416, 796) → (1310, 996) with #DDB255. Delete a keyway slot from (416, 846) to (1310, 942), then five 56 px pin holes from y 796 down to the keyway.
    4. Cap & Cam: add a steel #A9B1B5 retainer strip over the chambers, (460, 582) → (1300, 596), and a small cam tab behind the plug.
    Fig. 1 roughed in: a brass lock housing with five dark vertical pin chambers cut from its top, sitting over a dark cavity silhouette

  6. Select the plug with the Magic Wand

    Hatching has to stop at each part's edge, so select the part first. Choose the Magic Wand, untick Contiguous, and click the housing's brass. Contiguous off matters here: the chambers split the housing into separate islands, and you want them all.

    Click the Add Layer button, name the new layer Housing Hatch, and check the marching ants are still there. The selection survives the row change. Do the same for the plug, with a Plug Hatch layer above Plug.

    The Magic Wand options with Contiguous unticked, and marching ants around every brass region of the plug

  7. Fill the section hatching

    With each selection live, choose Edit → Fill with Pattern…:

    • Housing Hatch: the first hatch tile. Set Blend to Multiply and opacity to 38%.
    • Plug Hatch: the mirrored tile. Set Blend to Multiply and opacity to 30%.

    The pattern is anchored to the document, so the lines stay continuous across every island. Multiply lets the brass colour show through.

    Fig. 1 with forward-leaning hatch lines across the housing and backward-leaning lines across the plug, both darkening the brass slightly

  8. Draw the springs and the first driver pin

    Add a Springs layer. Pick the Brush at size 5 and hardness 100 in #C9D0D3. Drag a zigzag down each chamber, about 30 px wide with a turn every 20 px. Stop each one where its driver pin will start.

    On a Driver Pins layer, draw the first pin as a 48 × 64 rectangle in three flat tones. That's how period manuals shaded round parts:

    • mid #A9B1B5 for the whole pin
    • a 10 px light band #DCE2E4 just left of centre
    • a 13 px dark band #6C757A down the right edge

    Skip gradients here. Flat bands read as printed ink.

    White zigzag springs in all five chambers and one grey steel driver pin under the first spring

  9. Clone the pins and dash the shear line

    Clone the driver pin instead of redrawing it:

    1. Marquee it and press Cmd+C, then Cmd+V. The paste lands in place, on a new layer.
    2. With the Move tool (V), drag it 140 px to the right. Use arrow keys to land it exactly.
    3. Choose Layer → Merge Down.

    Repeat for the other chambers. In the locked view each driver sits at a different height, because it rests on a different length of key pin.

    On a Key Pins layer, fill five brass pins in #D2A443, 60, 88, 72, 96 and 66 px long. Give each a 12 px pointed tip, a #F0D38A light band and a #8E6A22 dark band. With no key they all hang to the same depth (y 902), so their tops land at different heights, and every driver pin crosses the shear line.

    Finally add a Shear Line layer. Marquee a 4 px-tall strip along the plug's top edge, (270, 794) → (1390, 798), and fill it with the dash pattern.

    Fig. 1 complete: five steel driver pins straddling an orange dashed shear line, with brass key pins hanging into the dark keyway below

  10. Insert the key

    Make a second group, Fig 2 Open, and rebuild the housing, plug and cavity 600 px lower, using the same shapes.

    The key goes on its own Key 2 layer, above the plug:

    • Blade: fill it with nickel #B7BDBF inside the keyway. Cut its top edge into V notches. Each notch bottom sits one key-pin length below the shear line, so the notch under the 96 px pin is the deepest.
    • Bow: a 90 × 108 ellipse-marquee fill outside the lock, with a 22 px hole deleted.
    • Tone: add a light #E6EAEA strip along the top, a shadow #737B7F strip along the bottom and a dark warding groove #5B6265 down the middle.
    Fig. 2 roughed in: the same housing and plug with a flat silver key filling the keyway, its top edge cut into V notches of different depths

  11. Lift every gap to the shear line

    Draw one spring and one driver pin, then clone them four times at +140 px with no vertical offset. With the key in, every driver sits at the same height.

    The key pins come next. Each one's top sits exactly on the shear line, and its point rests in its notch. Add the dashed shear line across this figure too, starting at the front of the lock.

    Compare the two figures: in Fig. 2, not one pin crosses the orange line. That's the whole poster.

    Fig. 2 finished: five compressed springs, steel driver pins sitting entirely above the orange shear line, and brass key pins resting in the key's notches entirely below it

  12. Rotate the keyway 30° for the face views

    In an End Views group, draw the lock's front face twice, at (240, 1900) and (550, 1900):

    • a brass circle, r 130, with an ink tick at 12 o'clock
    • an orange shear ring, r 99
    • a lighter plug circle, r 92

    On a Keyway layer, lasso a zigzag keyway slot and a small index notch on the left face.

    To turn the right face:

    1. Marquee a square centred on the left face, (146, 1806) → (334, 1994). Copy, paste in place and move it 310 px right.
    2. Re-marquee it, square and centred on that face, so the rotation pivots on the face's centre.
    3. With the Move tool, hold Cmd and drag the rotate handle clockwise. Cmd snaps in 15° steps, so it stops at exactly 30°.
    4. Press Cmd+D to commit.

    Only the keyway turns. The plug's shading stays put, because light doesn't rotate with the part.

    Add a black arc arrow concentric with the face (r 150) and a 30° label.

    At 147% zoom, two brass face views. The right keyway is inside a rotated transform box whose handles show a 30 degree clockwise turn, beside a black arrow and a 30° label

  13. Set the title and track the subtitle

    Make a Type group and drag it above the figure groups. Create each text in an empty spot, then move it into place.

    • Title: LOCKED and OPEN in Bebas Neue 290. Put LOCKED flush with the left margin (x 110) and OPEN flush right (x 1390), both with their tops at y 124. Centre an orange / in the gap between them.
    • Subtitle: ANATOMY OF THE PIN-TUMBLER CYLINDER in Bebas Neue 64 at y 362. Then raise its Letter spacing in the Text panel until it spans exactly 110 → 1390. Here that was 14.3.
    • Kicker: SHOP MANUAL · SECTION 4 · PLATE 07 in IBM Plex Mono Medium 20, flush right at y 84.
    The title LOCKED / OPEN in 290 px Bebas Neue with an orange slash, a small monospace kicker above right, and the subtitle letter-spaced to span the full margin

  14. Add captions, notes and the parts list

    Set the rest of the text in two faces only:

    • Figure captions: FIG. 1 — LOCKED and FIG. 2 — OPEN in Bebas Neue 64, at the left margin.
    • Notes: four short lines under each caption in IBM Plex Mono 21.
    • Shear line label: SHEAR LINE in orange Bebas 40, centred vertically on the dashed line.
    • Face captions: Bebas 36, centred under each circle.

    For the parts list, use monospace columns. IBM Plex Mono has the same advance width in every weight, so spaces line up the columns exactly:

    1. Type a header row, NO. PART QTY MATERIAL, in SemiBold 21.
    2. Set Line height to 1.52 in the Text panel. Then type eight rows in Regular 21, padding every part name to the same length (e.g. 3 SPRING 5 STAINLESS STEEL).
    The poster with FIG. 1 and FIG. 2 captions, short monospace notes in the left column, an orange SHEAR LINE label, face-view captions and a four-column parts list

  15. Snap the heavy rule to the grid

    Choose View → Show Grid, set Grid to 4px in the options bar, and make sure Snap is ticked. On a Rules layer, drag a marquee under the PARTS LIST heading. It snaps to a clean 560 × 4 px bar, (830, 1809) → (1390, 1813). Fill it with ink and hide the grid again.

    The table's other lines go on their own layers:

    • Table rules: 1 px lines between the rows, on a Table Rules layer at 40%.
    • Title block: a 2 px box from (830, 2112) to (1390, 2160), split into three cells: DWG. LO-07, SCALE 4:1 and SHEET 1 OF 1.
    • Band rules: full-width 3 px rules at y 428, 1066 and 1740.
    View → Show Grid on at 4 px with Snap ticked, and a 560 by 4 px marquee snapped exactly under the PARTS LIST heading

  16. Add balloons and leaders

    Drafting conventions to follow:

    • Numbers run in reading order. Balloons 1–5 sit in a row above Fig. 1: housing, retainer strip, spring, driver pin, key pin. 6 is the plug, 7 the key and 8 the cam.
    • Leaders are angled between 30° and 60°. They must never run along a spring or an edge. Each is a 3 px ink line ending in a 5 px dot on its part.
    • Balloons are ink circles (r 23) with a paper centre (r 20), on a layer directly below the number text. Each number is Bebas 32, centred to the pixel.
    • The pitch dimension has 2 px extension lines on the centres of pins 1 and 2, arrowheads on the line, and .156" PITCH set outside the extension lines so it doesn't crowd them.
    Numbered balloons 1 to 5 in a row above Fig. 1, balloon 6 on the plug, balloons 7 and 8 under Fig. 2, a pitch dimension with arrowheads, and angled leader lines ending in dots

  17. Outline the parts and finish the paper

    Save the effects for last, because they make every later edit slower.

    • Ink outlines: on every part layer (housing, plug, cap & cam, pins, key and faces), open ✦ and turn on Stroke: ink #1F1D1A, Width 2, outside.
    • Leader halos: on the Leaders layer, add a Stroke in the paper colour instead. The halo keeps the black leaders readable where they cross the dark chambers.
    • Paper grain: select Paper and run Filter → Add Noise… at Amount 12, Mono.

    Export with File → Quick Export PNG, and save the .lopsy so you can come back to it. The project reopened here pixel-for-pixel identical.

    A 120% close-up of Fig. 1 with crisp 2 px ink outlines on every part, and leader lines that stay visible over the dark chambers thanks to a thin paper-coloured halo
Lopsy showing the finished deep blue poster, with a huge black deep headline, a red sounding line dropping into eccentric blue circles, a red probe with sonar rings and blue knocked out of the circles in paper colour

Design a Swiss Style Exhibition Poster

Build a Swiss International Style exhibition poster in Lopsy with a strict grid, giant grotesk type, eccentric circles, halftone shading and a rotated caption.

  • Intermediate
  • 50 min