Team 2822D Active Build

Spoonbill

Hero Bot four-bar · center tower · rotating V5 claw · dual-wheel rear toggle

🔧 Building · Phase A Override 2026–27 Team 2822D

Spoonbill retro poster — vintage halftone illustration of a roseate spoonbill

// LINEAGE FROM V.1

From V.1

Inherits the Spartan Hero Bot V1.0 baseline (chassis, drivetrain, four-bar lift).

Changed

V5 claw → rotating claw.

Because

Cup orientation control for upside-down cups; rotation enables handoff without re-grip.

Evidence

Element-capture matrix scoring; cup orientation analysis.

[ SPOONBILL ROBOT PHOTO — DROP IN AS THE ROTATING CLAW COMES TOGETHER ]

📛 Why “Spoonbill”

The roseate spoonbill is the rotating-bill specialist of the wading-bird family. Where other waders hunt by spear (heron, crane) or by sweep at the water's surface (skimmer), spoonbills feed by sweeping their flat, spatulate bill side-to-side in a continuous rotating motion through shallow water — when the bill encounters prey, the bird snaps shut without breaking the sweep. The whole hunting strategy is built around the bill's rotational degree of freedom. Spoonbill (the robot) earns the name with a 5.5W gear mechanism on the V5 claw that rotates the manipulator independent of the lift — flip pins on their side for stable hex-face seating, invert cups loaded upside-down, reorient pin-on-cup combos during transit. The rotating claw is the same kind of degree-of-freedom unlock as the spoonbill's rotating bill: not a different mechanism, but the same mechanism with an added rotational axis that turns random-orientation into deliberate-orientation. Wading-bird family with Heron, Crane, Stork, Osprey, Pelican; the orientation-and-flip specialist of the fleet.

📝

Build context. Spoonbill is Team 2822D's Hero Bot-derived four-bar build — same architectural family as Pelican (Hero Bot four-bar with split tower) and Osprey (Hero Bot-derived chain-bar variant), all three descending from the four-bar baseline at Spartan Hero Bot V1.5. Same chassis, same drivetrain, same toggle approach (flex-wheel against perimeter-wall toggle), same V5 claw manipulator family as Pelican. The divergences are (1) center tower instead of Pelican's split rear tower, (2) gear-driven claw rotation for pin-flipping and cup-orienting, and (3) dual-wheel rear toggle for 2-point grip when backing into the perimeter wall.

⚠

Diverges from the public-site V1.5 spec. The Override hero-bot architecture published at spartandesignrobotics.org is the Hero Bot four-bar baseline with rear tower and static V5 claw. What Team 2822D is actually building in Phase A is the four-bar with center tower, rotating claw, and dual-wheel rear toggle. The public site will be reconciled with the team's actual builds in a later update.

Architecture Match cycle Rotating claw Center tower Side view Top view Rear view Dual-wheel toggle Motor budget Inspection Game-ready Decision matrix Open questions Port map

Architecture at a glance

Drivetrain4 × 11W Blue cartridge · 44W · preseason carryover from V1.5 baseline
LiftMirrored four-bar lift (parallelogram), 2 × 11W Red 100 RPM · ~14″ arm length · 4″ pivot spacing · arm rests folded back over chassis-back at loader-receive height
Tower1×5×1 aluminum C-channel at chassis center (NOT split rear like Pelican) · ~7″ above chassis top → lower-pivot at 11″ off field tile
ManipulatorV5 claw (1 × 5.5W) at end of four-bar · standard claw kit grip geometry
Claw rotation (★ unique)1 × 5.5W gear mechanism at the lift-end-bar driving claw rotation around its grip axis · flip pins, invert cups, reorient pin-on-cup combos during transit
Toggle (★ dual-wheel rear)2 × 5.5W half-motor · 4″ flex wheels mounted on chassis rear face, spaced ~14″ apart laterally · both wheels engage same toggle bar simultaneously for 2-point grip when robot backs into perimeter wall
Total motors10 motors · 88W exactly at R10a cap (no spare)
PneumaticsOptional — if claw rotation adds pneumatic cushioning later (e.g., spring-loaded tip), 1 cylinder + 1 solenoid per R25
Chassis18″ × 18″ × 4″ aluminum 1×2 box rail (same as V1.5 baseline)
Defining capabilityElement reorientation during transit — the claw can rotate while the lift travels, decoupling orientation from lift trajectory.

Match cycle — loader → orient → goal

Spoonbill's defining cycle has an extra strategic step that the other Hero Bot-derived builds don't: orientation correction during transit. The loader is non-deterministic about element orientation — cups can drop right-side-up or upside-down, pins can land on any of six hex faces, pin-on-cup combos can drop in either order. Pelican and Osprey deposit whatever the loader gives them; Spoonbill rotates the claw to fix orientation before deposit, which improves stack stability on goals and enables deliberate pin-on-cup placement.

Position chassis-back at loader. Robot drives back-end-first to the alliance loader. Four-bar arm at rest, folded back over chassis-back area, claw at ~11″ off tile.
SG11 loader-raise + drop. Drive Team raises the loader (per SG11), element drops into open V5 claw at back-rest position. Claw closes (V5 claw motor, ~150 ms).
★ Orient during transit (the unique step). While the lift swings up and forward and the chassis drives toward the goal, the claw-rotation motor fires to align the element. Pin upside-down? Rotate 180°. Cup on its side? Rotate 90°. Pin-on-cup combo? Rotate to put pin-up or cup-up depending on intended deposit order. Driver reads element orientation from the camera or by feel and triggers a rotation preset.
Drive forward to goal + lift to deposit height. Lift four-bar continues swinging up over center tower; claw arrives at goal-deposit height matching target goal (8.77″ tall, 5.77″ short, or 3.25″ alliance — depositing at any of the three by stopping lift at appropriate angle).
Open claw → element drops onto goal in correct orientation. The V5 claw releases. Element falls in the orientation Spoonbill chose, not the orientation the loader gave.
Reset. Lift swings back down to rest position during drive away. Claw rotation returns to neutral pose. Cycle repeats.

🎯

Why the rotation step matters strategically: hex-faced pins are stable on goals only when seated on a flat hex face, not on a corner edge. A pin loaded by the loader in a random orientation has a ~50% chance of landing “edge-down” on the goal — unstable, prone to rolling off. Rotating the pin before deposit to ensure it's flat-face-down adds reliability that compounds over a match. Same logic for cups: a cup deposited upside-down on a goal blocks subsequent stacking; rotating to right-side-up keeps the goal stack-able. Net cycle cost: ~0.3-0.5 s per cycle (rotation overlaps with drive + lift), net benefit: higher percentage of deposited elements stay scored over the match.

Rotating claw — the orientation degree of freedom

Spoonbill's distinctive subsystem is a 5.5W gear mechanism mounted at the lift's end-bar that rotates the entire V5 claw assembly around its grip axis. This is the “extra DOF” that Pelican's static claw doesn't have, and it's the design feature that earns Spoonbill its strategic identity.

Mechanism

Claw rotation drive: Motor 1 \times 5.5W half-motor (V5 cartridge) Mounting Fixed to the four-bar end-bar, between the two arm pivots Drive Bevel gear or worm gear stage from motor shaft to claw mount axis (claw mount axis is perpendicular to motor shaft and parallel to the lift's transit direction) Reduction ~10:1 worm gear (gives positional holding torque without back-drive; rotation lock when motor is unpowered) Rotation range 0 to 360° continuous (no end stop required) Position feedback Pot V2 on the claw mount axis \cdot reads claw rotation angle to ~1° resolution \cdot preset positions in driver code: 0° (neutral), 90°, 180°, 270°

Driver controls and presets

D-pad up: rotate claw to 0° (neutral, default loader-receive orientation)
D-pad right: rotate claw to 90° (sideways grip; useful for cup-on-its-side scenarios)
D-pad down: rotate claw to 180° (inverted; flips an upside-down cup right-side-up)
D-pad left: rotate claw to 270° (mirror sideways)
Right stick (rotation axis): manual continuous rotation override for non-preset scenarios

The four preset bindings handle the common cases; the manual override handles edge cases. The worm gear's holding torque means the claw stays at whatever angle it was last commanded to — no power consumed to maintain orientation, only to change it.

Strategic plays unlocked

Three categories of plays that the rotating claw enables and that other Hero Bot-derived builds can't execute reliably:

1. Pin reorientation for stable hex-face seating. Pins are 6.5″×1.6″ hex extrusions; they're stable on goals only when a flat hex face contacts the goal lip, not when a corner edge contacts it. A pin received from the loader in a random hex rotation has a 1-in-6 chance of being in the “wrong” rotation by ~30°. Rotating the claw 30-60° before deposit aligns the pin's flat face with the goal lip. Result: deposited pins stay seated; goal stacks stay stable.

2. Cup inversion. Cups loaded upside-down (open-end facing down) can't be stacked on (the closed bottom blocks subsequent elements). Rotating the claw 180° during transit inverts the cup so its open end is up at deposit. Result: every cup deposited is stack-able; alliance partner can deposit pins or more cups on top.

3. Pin-on-cup combo deliberate ordering. When the loader drops a pin-on-cup combo, the order is determined by loader timing and is non-deterministic. Spoonbill can deposit the combo in EITHER order by rotating during transit: pin-up (cup deposits first, pin lands on top) or cup-up (pin deposits first, cup lands on top). Result: Spoonbill turns a random combo into a chosen-order deposit, which has scoring implications when the alliance partner is also depositing combos.

🎯

The rotation is also a recovery mechanism. When something goes mechanically wrong — element shifts in the claw during driving, lift jolt during defensive contact misaligns the grip — the rotating claw can fix it without requiring a full re-grip cycle. Driver hits a preset, claw rotates, problem solved. This kind of in-cycle recovery is what makes the orientation DOF more than “a nice-to-have”: it's a reliability multiplier. Engineering notebook narrative writes itself.

Center tower — placement and trade-offs

Pelican mounts the four-bar lift at the chassis rear in a split-tower configuration; Osprey mounts a chain bar at chassis center; Spoonbill mounts a four-bar at chassis center. The center-tower placement is the architectural divergence from Pelican.

Geometry

Tower spec (working assumption): Tower 1 \times 5 \times 1 aluminum C-channel at chassis geometric center Tower height 7″ above chassis top \to lower-pivot at 11″ off field tile Pivot spacing 4″ vertical (standard four-bar) \to upper-pivot at 15″ off tile Arm length ~14″ (matches Pelican baseline; long enough to reach over goals without chassis nesting required) Rest position Arm folded BACK — manipulator over chassis-back at ~11″ off tile (catches loader drop at SG11-raised-loader height) Lift trajectory Arm pivots up and forward through vertical, manipulator travels through ~22″ peak height during transit Deposit position Arm folded FORWARD — manipulator at chassis-front at deposit height (varies by goal: 9-10″ for tall, 6-7″ for short, 4″ for alliance, by stopping lift at appropriate angle)

Center vs split vs chain-bar (the Hero Bot-derived family comparison)

Aspect	Pelican (split rear tower, four-bar)	Spoonbill (center tower, four-bar)	Osprey (center tower, chain bar)
Tower position	Chassis back, 3 × C-channels in left+center+right config	Chassis center, 1 × C-channel	Chassis center, 1 × C-channel
Lift mechanism	Four-bar in right bay (mirrored 2 × 11W)	Four-bar mounted on center tower (mirrored 2 × 11W)	Single chain bar (1 × 11W)
Toggle position	Left bay of split tower (in-tower-protected)	Chassis rear face (cantilever exterior)	Both chassis flanks (mirrored cantilevers)
Goal coverage	All 3 (variable lift angle)	All 3 (variable lift angle)	Tall-locked (single committed arc)
Lift motor count	2 (mirrored four-bar)	2 (mirrored four-bar)	1 (single chain bar)
CoG balance	Asymmetric (lift-heavy right + counterweight left)	Symmetric (lift centered)	Symmetric (lift centered)
Front cavity	Optional (alignment cavity)	Not required (arm reaches over goal)	Required (goal nests in chassis)

The center-tower placement gives Spoonbill symmetric CoG — the heavy lift mass sits at chassis center rather than rear-biased. This makes the chassis less tipping-prone during sudden direction changes (defensive contact, fast pivots) than Pelican's rear-loaded tower. Trade-off: the chassis center is normally “open space” for transit and manipulator clearance; a tower at center constrains the lift's swing volume to passing OVER the tower (which the four-bar geometry naturally accommodates) and gives up the option to nest a goal inside the chassis (which Osprey uses but Pelican and Spoonbill don't need because their arms reach over goals).

⚠

Open question for the team: the working assumption is 7″ tower / 14″ arm. Both numbers need physical bench validation: tower must clear the lift's full swing without the arm hitting the tower top, and arm must reach over the tall goal lip with the manipulator dropping a cup at controlled height. Build a paper-and-cardboard mock-up before committing the C-channel cuts. See open questions below.

Side view — center tower, four-bar lift, rotating claw

Side view (right side of robot, lift cycle through 180° arc) · to scale, 1″ = 12px

Drawn to scale (1″ = 12px). Center tower 7″ tall mounts the four-bar lift at chassis geometric center. Lower pivot at 11″ off tile, upper pivot at 15″ (4″ spacing, standard). Two parallel arms 9″ long with end-bar form the parallelogram — this keeps the V5 claw oriented level through the entire arc, just like a chain bar's static-sprocket geometry. Three lift positions shown: REST (orange, folded back over chassis-back at 11″ off tile, ready for SG11-raised loader drop). MID-ARC (yellow, dashed, arm vertical, claw at peak 22″ off tile during transit). DEPOSIT (orange, folded forward over chassis-front at 11″ off tile, claw drops cup onto tall goal at 8.77″ with ~2″ clearance). Unlike Osprey's chain bar (single committed arc to one goal height), Spoonbill's four-bar can stop mid-arc at any angle — deposit at tall, short, or alliance goals by lift-angle adjustment. The rotating claw mechanism rides at the end-bar between the two arms (small yellow circle at end of arm in each position), spinning the claw's grip axis independent of the lift's vertical motion.

Top view — center tower, lift symmetry, dual-wheel rear toggle

Top view (looking down) · chassis layout + dual-wheel rear toggle · 1″ = 12px

Top view of Spoonbill's 18″×18″ chassis. The four-bar lift mounts at the geometric center (small grey rectangle = tower footprint). At rest, the lift extends BACK toward the chassis rear (loader-receive position); at deposit, it extends FORWARD over the chassis front (dashed orange). The four drive motors sit at chassis corners. The two toggle wheels are mounted on the chassis BACK FACE, spaced 14″ apart laterally — at the chassis rear-top and rear-bottom edges in this top-down view. When the robot backs perpendicular to the perimeter wall, both wheels contact the same toggle bar at two points along its 26″ length (toggle bar shown as dashed yellow line projecting parallel to chassis-back; engagement points marked as yellow circles). The 2-point grip means the toggle bar can't slip or twist out of contact — both wheels apply rotation torque simultaneously. Single button bound to fire both motors together; the wheels are one mechanism for driver purposes.

Rear view — the dual-wheel grip geometry

Rear view (looking at chassis back face) · toggle engagement geometry · 1″ = 12px

Rear view of Spoonbill showing the dual-wheel toggle engagement geometry — the architecturally distinctive feature. Chassis back face is 18″ wide × 4″ tall (orange rectangle at tile level). Two 1×2×9 aluminum C-channel brackets rise vertically from the chassis frame, one near each side edge of the back face. Each bracket carries a 4″ ⌀ flex wheel at its top, with a 5.5W half-motor mounted at the bracket base driving the wheel via short chain. Wheel centers are at 12.5″ off field tile, matching the toggle assembly center on top of the 11.54″ perimeter wall. Lateral spacing between wheel centers is 14″ (chassis is 18″ wide; 2″ margin from each side edge keeps the brackets within the chassis envelope). When the robot backs perpendicular into the perimeter wall, both flex wheels engage the same 26″ toggle bar at two points 14″ apart — spanning 54% of the bar's length. The 2-point contact distributes rotational torque across the bar, eliminates the “single-point pivot” failure mode, and self-centers laterally if the robot is slightly off-square to the wall.

Dual-wheel rear toggle — 2-point grip

Spoonbill's toggle architecture is a different answer to the same problem Pelican (single-side, in-tower) and Osprey (dual-side mirrored, chassis flanks) solved differently. The dual-wheel rear approach optimizes for engagement reliability per attempt: when Spoonbill commits to a toggle, the 2-point grip ensures the toggle rotates without slip, even under marginal grip conditions. Trade-off: engagement requires the chassis to back perpendicular into the wall, which is a different motion path than the loader-goal cycle.

Engagement workflow

Driver identifies toggle target. Toggle position on perimeter wall is observed visually.
Chassis approach: back perpendicular to wall. Driver maneuvers chassis-rear-first toward the toggle position. Both flex wheels are mounted on the chassis-back face; alignment is by chassis lateral position relative to toggle bar center.
Contact + grip. Both wheels touch the 26″ toggle bar simultaneously at two points 14″ apart along its length. Wheels self-center if approach is slightly off-square — the bar's continuous length means grip happens regardless of exact contact point.
Rotation pulse. Driver presses toggle button; both 5.5W motors fire simultaneously. Both wheels spin same direction (toward chassis top), rolling the toggle bar around its long axis. Pulse duration ~0.5-0.8 s for 120° rotation (one face advance).
Disengage + return to cycle. Driver drives forward away from wall, returning to loader-goal cycle motion.

Why 2-point grip wins on reliability

Engagement comparison: Single-point grip (Pelican): \cdot One contact point on toggle bar \cdot Risk: bar can slip past wheel under torque (point-contact friction limited) \cdot Risk: lateral chassis position must be precise \cdot Best case: clean rotation; Worst case: wheel skips, no rotation 2-point grip (Spoonbill): \cdot Two contact points 14″ apart on 26″ bar \cdot Torque applied at two points = double effective grip \cdot Lateral position forgiveness: \pm6″ off-center still gets full grip \cdot Bar can't pivot or slip out of contact during rotation \cdot Best case: clean rotation; Worst case: still rotates (one wheel grips even if other skips, bar still rolls)

Driver controls

L-trigger: fire both rear toggle motors simultaneously, ~0.5 s pulse for one face advance (120°)
L-trigger long-press: continuous fire while held; for multi-face advances or extended grip troubleshooting
R-trigger (optional): reverse direction (both motors spin opposite way) — useful if a face advance overshoots or the toggle needs to roll back

Single-button-fires-both is the default because the two wheels are mechanically one mechanism; there's no driver decision to be made about which side to use. This is simpler than Osprey's L/R independent control but also less flexible — Spoonbill can't engage a toggle while driving past it the way Osprey can.

⚠

Cycle interruption cost. Backing into the wall is a deliberate motion path that interrupts the loader-goal flow. Estimated cost: 2-3 s per toggle engagement (1 s to back into position, 0.5-0.8 s to pulse rotation, 1 s to drive away). Compare to Pelican's drive-by single-side (~1 s opportunistic) and Osprey's any-side dual mirrored (~1 s, no chassis reorientation). Net effect: Spoonbill engages fewer toggles per match, but each engagement has higher rotation success rate. Over a season, the trade-off depends on how often toggles actually slip on Pelican-style single-point grip — if they slip 20%+ of the time, Spoonbill's reliability wins; if they slip <10%, Pelican's pace wins. This is a Phase A bench-test question.

Motor budget — 88 W exactly at cap

Spoonbill motor budget: Drive .................. 4 \times 11 W Blue ..... 44.0 W Lift (mirrored 4-bar) .. 2 \times 11 W Red ...... 22.0 W V5 claw (grip) ......... 1 \times 5.5 W ......... 5.5 W Claw rotation (★) ...... 1 \times 5.5 W ......... 5.5 W Toggle (rear, top) ..... 1 \times 5.5 W ......... 5.5 W Toggle (rear, bottom) .. 1 \times 5.5 W ......... 5.5 W Total ................................. 88.0 W \leftarrow EXACTLY AT CAP Cap (R10a) ........................... 88.0 W Pneumatics (separate from W budget): \cdot Optional for Phase B if claw cushioning added \cdot per R25 Motor port count: 10 motors

Spoonbill is at the R10a 88W cap with zero spare wattage. This matches Pelican's budget pressure and is the cost of the unique features: the 5.5W claw rotation motor and the second 5.5W rear toggle motor each consume capacity that the V1.5 baseline doesn't have spare. There is no buffer for in-season decisions — if any subsystem needs more wattage, something else has to be reduced.

⚠

Budget pressure means downgrade decisions are pre-committed. If the bench-test reveals that a 5.5W toggle motor is marginal against actual toggle resistance (the team would normally upgrade to 11W like Osprey's chain bar lift), Spoonbill has no spare wattage for the upgrade. Mitigation paths if pressure shows up: (a) drop the rear-bottom toggle motor (revert to single-wheel grip, still mounted on chassis rear, frees 5.5W); (b) reduce drive cartridge from Blue to Green (slower drive, frees per-motor wattage to redistribute); (c) accept the marginal grip and rely on long-press button for multi-pulse rotation. The team should choose a fallback path during Phase A planning, not in the moment when the issue appears.

Inspection compliance — R3, SG2, SG12

R3 — 18×18×18″ start cube

R3 check at match start: Chassis footprint: 18″ \times 18″ ✓ Chassis height: 4″ ✓ Center tower: 7″ above chassis \to 11″ off tile ✓ Lift at REST (folded back): arm horizontal back, manipulator at chassis-back edge at 11″ off tile \to 11″ vertical ✓ \to arm tip at chassis-back edge x=192 ✓ Toggle brackets (rear): 1\times2\times9 vertical, top at 12.5″ off tile ✓ Toggle wheels: 4″ ⌀ centered at 12.5″ off tile \to top of wheel at 14.5″ off tile ✓ (under 18″) \to wheels protrude up to 14.5″ vertically ✓ Lateral wheel position: wheels at chassis-rear x=192 + bracket thickness; wheels span 14″ spaced at chassis-y=\pm7″ from center \to fully within 18″ chassis envelope ✓ R3: PASS — vertical envelope used to 14.5″ (toggle wheels), horizontal margin clean

SG2 — 24×24″ horizontal during match

Lift at deposit position has the four-bar fully extended forward; the manipulator at chassis-front edge. Horizontal extent equals chassis footprint (18″), well under 24″ SG2 cap. SG2: PASS with 6″ horizontal margin.

SG12 — 18″ vertical in midfield endgame

During endgame midfield play (last 10 s), vertical limit drops to 18″. Spoonbill's lift mid-arc has the manipulator at peak ~22″ off tile (lift fully vertical) — over the SG12 cap.

Mitigation: lift must be at REST or DEPOSIT position (both at 11″ off tile, manipulator at chassis edge) before entering midfield in endgame. Programming: bind a button OR a time-trigger that retracts lift to REST at endgame. SG12: PASS conditionally on programming discipline.

⚠

The toggle wheels are fixed-position (not retractable). Toggle wheels protrude up to 14.5″ vertical at all times during the match (mounted rigid on the chassis-back face). They are under the SG12 cap of 18″, so they're compliant — but the team should verify with the inspector that the wheel-top height (14.5″) is measured correctly and that no vertical wheel deflection during defensive contact pushes any element past the 18″ cap. Rigid mounting + bench-test of contact deflection is the documentation requirement.

Game-ready analysis

Goal coverage (variable lift angle)

Goal	Goal height	Manipulator deposit height	Reliability
Tall center	8.77″	~10-11″ (lift at full forward)	High — primary scoring target
Short neutral	5.77″	~7-8″ (lift stopped mid-forward)	High — lift-angle adjustment
Alliance	3.25″	~5″ (lift partial forward)	Good — lift-angle adjustment
Loader receive (chassis back)	~12″ (SG11 raised)	~11″ rest position	High — designed input

Like Pelican, Spoonbill covers all three goal heights via lift-angle adjustment. Unlike Pelican, Spoonbill can additionally rotate the element during transit, so deposits land in the orientation Spoonbill chose. This is a strategic capability difference, not a coverage difference.

Cycle time math

Loader-to-goal cycle (with optional orientation step): Drive back-end-first to loader 2.0 - 3.0 s SG11 loader raise + drop into back-rest 1.0 - 2.0 s V5 claw close on element 0.15 s Drive forward to goal (overlaps lift) 2.0 - 3.0 s ★ Claw rotation to orient (overlaps drive) 0.3 - 0.5 s (NEW: in parallel with drive) Lift to deposit angle (overlaps drive) 1.0 - 1.5 s Position chassis at goal 0.3 s Open V5 claw \to element drops 0.15 s Reset lift to rest (overlaps drive away) overlapped ----------- Total loader-to-goal cycle: ~7.0 - 10.0 s (rotation step adds ~0 cost when fully overlapped) Toggle engagement (separate from cycle): Back perpendicular into wall ~1.0 s Toggle pulse (both wheels) 0.5 - 0.8 s Drive away from wall ~1.0 s Total toggle engagement: ~2.5 - 3.0 s (interrupts loader-goal cycle; perform between cycles)

Spoonbill's cycle is comparable to Pelican (~6-11 s) and Osprey (~7-10.5 s). The orientation step adds zero cost when fully overlapped with drive (which is the typical case). The toggle engagement is more costly than Pelican or Osprey because of the back-into requirement — Spoonbill should target fewer-but-more-reliable toggle attempts.

Auton routine (15 s)

0.0–0.5 s: Pre-loaded element; lift at REST. Spoonbill starts in standard auton-ready pose.
0.5–3.0 s: Drive forward to nearest scoring position; lift swings forward through arc.
3.0–4.0 s: Optional claw rotation if pre-load orientation is wrong (typically not in auton; pre-load is staged correctly).
4.0–5.0 s: Position at goal, open claw, score #1.
5.0–7.5 s: Drive back-end-first to loader.
7.5–9.5 s: SG11 raise, element drop, claw close.
9.5–12.0 s: Drive forward, lift to deposit, optional rotate.
12.0–13.5 s: Score #2.
13.5–15.0 s: Drive back, position for handoff.

Realistic auton output: 2–3 scores plus auton bonus. Same range as Pelican and Osprey.

Driver-control routine (1:45)

0:00–1:30 (cycle phase, ~90 s): Loader-to-goal cycles. Target 9–13 cycles. Most cycles include a rotation orient step that overlaps with drive; orientation correction is the standard play, not a special case.
Toggle engagements (~2-3 in match, optimistic): When toggle position is favorable for back-into approach (toggle on the alliance-near wall, no defensive pressure), commit to the engagement. Each costs 2-3 s but has higher rotation success rate than drive-by approaches.
1:30–1:45 (endgame): Lift to REST (under 18″ for SG12), drive to endgame zone.

Realistic driver-control output: 9–13 cycles + 2–3 toggle engagements. Combined with auton: 11–16 elements scored per match.

Strengths

Element orientation control. The rotating claw adds a strategic capability no other fleet build has — pin-flipping, cup-inversion, pin-on-cup combo ordering.
2-point toggle grip. Higher per-engagement reliability than single-point approaches; bar can't slip out of contact.
Symmetric center-tower CoG. Mass distribution centered at chassis center; less tipping under defensive pressure than Pelican's rear-tower.
All three goal heights via lift-angle adjustment (same flexibility as Pelican).
Notebook narrative. The rotating-claw is a standout design feature with a clean strategic justification — engineering notebook judges respond to “we identified a non-determinism source and added a DOF to control it.”
Recovery capability. Mid-cycle element shifts can be corrected via rotation rather than re-grip cycles.

Limitations

88 W exactly at cap, zero spare. No headroom for in-season subsystem upgrades.
Toggle engagement requires perpendicular back-in. Cycle interruption cost ~2-3 s per toggle (vs Pelican's drive-by ~1 s).
10 motors total. Highest motor count in the fleet; more wiring complexity, more failure modes by count.
Worm gear back-drive. If the worm gear in the rotation mechanism fails open (loses holding torque), the claw can spin freely under gravity — bench-test failure modes before committing.
Tower-blocking arm sweep risk. Center tower is at chassis center; the four-bar arm sweep passes OVER the tower top. Tower must be tall enough that arm clears it AND short enough that R3 fits. Geometry is tight.
No floor pickup. Same as Pelican and Osprey — loader-only ingestion.
Build complexity from rotating claw + dual toggle. Spoonbill has TWO unique subsystems vs Pelican's ONE (split tower) and Osprey's TWO (chain bar + dual mirrored toggle). Highest build hours of the Hero Bot-derived family.

Match scenarios

🏆

Qualifying matches. 11–16 element score with high stack reliability is mid-tier offensive output but with above-average per-element scoring efficiency. The orientation control means alliance partners can deposit on top of Spoonbill's deposits with confidence. Pair with Skimmer or 355Z-derived ally for floor-pickup coverage; Spoonbill owns the loader-and-orient role.

⚠

Elimination matches. The 2-3 s toggle engagement cost is exposed under defensive pressure — defenders will recognize that backing-into-wall is a vulnerable motion path and contest the back-approach. Mitigation: if defense shuts down toggle engagement, Spoonbill falls back to pure loader-goal cycling at the same pace as Pelican (without the toggle scoring). The orientation control still works during cycling and is harder for defense to disrupt. Strategic adjustment: in elims with strong defense, target loader-goal cycles only and skip toggles unless an opportunistic engagement appears.

🎯

Strategic edge: orientation as a multiplier. The rotating claw isn't a separate scoring vector — it's a multiplier on every cycle. Each element deposited correctly oriented stays scored at higher rates than a randomly-oriented deposit. Over a 90-second driver-control phase with 9-13 cycles, even a 10% reliability improvement translates to 1+ additional retained score per match. That's a real strategic edge that compounds across a season. Coach call: Spoonbill is the right pick when the team values per-element scoring quality and is willing to sacrifice some toggle pace for orientation reliability. For a team that practices a lot and can master the rotation presets, this is a strong architecture.

Decision matrix — Spoonbill vs. fleet

Six-dimension comparison across Spoonbill and the named team-builds + active concepts. Scored 1–5 (5 = best), out of 30 total.

Dimension	Skimmer (2-bar + tube)	Pelican (4-bar + claw)	Spoonbill (4-bar + rot claw)	Osprey (chain-bar)	Falcon (4-DOF)
Goal coverage	4	5	5 all 3 + orientation control	3	5
Cycle time (avg)	5	3	3 ~7-10s/cycle; toggle costs 2-3s	4	5
Build complexity	3	3	2 rot claw + dual toggle = highest	4	3
Driving cognitive load	4	3	3 rotation presets simple; toggle back-in is a gesture	4	2
Notebook story	5	4	5 rotating-bill metaphor + DOF unlock + 2-point grip	4	4
Risk of failure (higher = lower risk)	4	4	3 88W at cap; 10 motors; worm gear back-drive risk	4	4
Total (/30)	25	22	21	23	23

🎯

Spoonbill scores 21/30 — the lowest in the Hero Bot-derived family, paying 1-2 points each on build complexity (10 motors, two unique subsystems) and risk (88W exactly at cap, worm gear). BUT it scores 5/5 on goal coverage AND notebook story — the orientation-control strategic capability and the rotating-bill metaphor are genuinely distinctive. Strategic identity: Spoonbill trades cycle pace and build simplicity for orientation precision and scoring reliability. The 21-point total isn't a weakness ranking — it's the cost of doing something that none of the other architectures can. For a team committed to the “orient before deposit” play and willing to invest the build hours and master the rotation presets, this trade-off can be worth it. The four Phase A team builds together (Skimmer 25, Osprey 23, Pelican 22, Spoonbill 21) cover four architecturally distinct strategies; that's strong fleet diversity for the engineering notebook narrative.

CAD starting point — numbers for OnShape

CHASSIS18″ × 18″ × 4″ aluminum 1×2 box rail (V1.5 baseline)
CENTER TOWER1×5×1×14 aluminum C-channel (length = N/2 = 7″), vertical, mounted at chassis geometric center on top of chassis frame.
FOUR-BAR LIFT2 × 1×2×18 aluminum C-channel arms (9″ length each, in parallel-bar config). Pivots: lower at 11″ off tile, upper at 15″ off tile (4″ vertical pivot spacing on tower).
END-BAR1×2×8 aluminum C-channel (4″ length), vertical, connecting front ends of upper and lower arms. Carries V5 claw mount + rotation gear + Pot V2.
LIFT MOTORS2 × 11W Red 100 RPM, mirrored on left and right sides of center tower at lower-pivot. Direct drive via shaft through pivot. Rubber band assist count TBD per bench-test.
V5 CLAWStandard V5 claw kit. Mount plate: bolted to end-bar via 4× #8-32. Grip axis vertical (claw opens horizontally).
CLAW ROTATION GEAR (★)Worm gear stage between 5.5W half-motor and claw mount axis. Worm: 1-tooth, on motor shaft. Worm wheel: 36-tooth (36:1 reduction), keyed to claw axis. Holding torque from non-back-drivable worm geometry. Pot V2 on claw axis for position feedback.
CLAW ROTATION MOTOR5.5W half-motor mounted on end-bar adjacent to claw mount.
REAR TOGGLE BRACKET (×2)1×2×18 aluminum C-channel (9″ length), vertical, mounted on chassis-back face, one near each side edge of rear face. Spacing 14″ lateral (chassis-y center ±7″). Bolted to chassis frame with 4× #8-32 hardware per bracket.
REAR TOGGLE FLEX WHEEL (×2)4″ ⌀ × 1″ thick flex wheel, 45A durometer (start; downgrade to 30A if grip marginal). Mounted on 0.25″ stub axle at top of bracket. Wheel center at 12.5″ off field tile. Wheel axis horizontal pointing forward (into chassis-back-face plane).
REAR TOGGLE MOTOR (×2)5.5W half-motor mounted at base of each bracket. 12T → 24T = 2:1 chain reduction (#25 chain) to flex wheel sprocket.

Open questions for the build team

Tower height vs arm length geometry. Working assumption: 7″ tower + 9″ arms. Alternatives: 5″ tower + 11″ arms (lower pivot, longer arms; manipulator reaches further); 9″ tower + 7″ arms (higher pivot, less reach but more vertical clearance for arm-over-tower swing). Build cardboard mock-up with all three configurations, verify arm clears tower top in mid-arc and reaches goal-front at deposit. Lock decision before machining tower C-channel.
Worm gear ratio for claw rotation. 36:1 working assumption gives slow rotation (~30 RPM at motor stall) but strong holding torque. Alternative: 24:1 (faster rotation ~50 RPM, less holding torque). Alternative: bevel gear stage (faster, but back-drives under load — needs mechanical brake or constant motor power to hold position). Worm gear is the safe choice; bench-test rotation speed against driver patience to confirm.
Rear toggle wheel durometer: 45A vs 30A. Same question as Osprey's toggle. 45A gives positive grip; 30A more forgiving. Bench-test against actual perimeter toggle bar; measure stall current and rotation success rate. Document choice and rationale in EN4.
Rotation preset count: 4 vs more. D-pad gives 4 cardinal presets (0, 90, 180, 270). For pin hex orientation, 6 presets (one per hex face) might be more useful — but D-pad doesn't bind 6 cleanly. Alternative: bind 4 cardinals to D-pad and use stick for fine adjustment between them. Test in driver practice; if drivers want hex-specific presets, redesign control mapping.
Toggle wheel cantilever bracing. The rear-mounted brackets are ~9″ vertical cantilevers extending from chassis-back. Defensive contact on the brackets could bend them. Cross-brace from each bracket top back to chassis frame at ~6″ height (similar to Osprey's bracket bracing); confirm geometry doesn't interfere with toggle-bar engagement.
Lateral spacing of toggle wheels. Working assumption is 14″ (allowing 2″ margin from each chassis side edge). Could go wider (16″ for more bar-coverage) or narrower (12″ for less moment on brackets). Wider gives more lateral position forgiveness; narrower gives less torque on brackets. Bench-test both with cardboard chassis mock-up + actual toggle prop.
Wheel alignment with toggle bar. If chassis is not perfectly perpendicular to wall when backing in (off by 5-10°), do both wheels still engage cleanly? Bench-test the wheel-to-bar contact angle envelope. May need flex-wheel compliance or bracket compliance to absorb minor misalignment.
Rubber band assist sizing for four-bar lift. Four-bar arm + manipulator + rotating-claw mass + element load creates torque demand. Bench-test with arm at horizontal forward (worst case for tipping moment); add bands until arm holds horizontal at zero motor power, then test rotation under that resistance. Document final band count in EN4.
SG12 endgame stow-arm automation. Same as Osprey: lift mid-arc puts manipulator at 22″ off tile, over the 18″ SG12 cap. Bind a button OR time-trigger that retracts lift to REST at endgame. Don't rely on driver memory.
Worm gear failure mode. If worm gear fails (tooth shear, lube degradation), claw spins freely under gravity. Mitigation: limit switch detects un-commanded rotation and triggers emergency stop on rotation motor; rebuild gear stage during inter-match break. Document failure mode and recovery procedure.

Relationship to the Hero Bot-derived family

Spoonbill, Pelican, and Osprey are three sister-bots — all descend from the Spartan Hero Bot V1.5 four-bar baseline. They share chassis, drivetrain, and a flex-wheel toggle approach (with three different mounting strategies). The architectural divergences are in the lift mechanism, the manipulator, and the toggle position.

Dimension	Pelican (2822C)	Spoonbill (2822D)	Osprey (2822E)
Lift architecture	Four-bar (mirrored 2 × 11W)	Four-bar (mirrored 2 × 11W)	Single chain bar (1 × 11W)
Tower placement	Split rear tower (3 C-channels)	Center tower (1 C-channel)	Center tower (1 C-channel)
Manipulator	V5 claw (static)	V5 claw + rotation gear (DOF unlock)	Pincer or polycarb tube
Goal coverage	All 3 (variable angle)	All 3 (variable angle) + orientation control	Tall-locked (committed arc)
Toggle architecture	Single 11 W in left bay (in-tower)	Dual 5.5 W on rear face (2-point grip)	Dual 5.5 W mirrored flanks (any-side)
Toggle engagement	Drive parallel, single contact	Back perpendicular, 2-point contact	Drive past either side, single contact
Total motors	9 (88W at cap)	10 (88W at cap)	8 (77W, 11W spare)
Strategic role	Mid-tier consistent + defensive durability	Orientation precision + scoring quality	Tall-goal pace + repeatability
Best alliance role	Cycle reliability anchor	Stack-quality anchor (deposits stay scored)	High-value cycle anchor (tall-goal focus)

Together the three Hero Bot-derived builds explore three distinctly different strategic profiles within a shared chassis platform. The engineering notebook can frame this as “same Hero Bot chassis, same drivetrain, same flex-wheel toggle approach — three intentionally different lift+manipulator+toggle combinations exploring different trade-offs along the cycle-pace, scoring-quality, and toggle-reliability axes.” Strong design-tradeoff narrative for judges; the inter-team comparison material is rich.

Port map (template — fill in as built)

Planned port assignments for the 10-motor configuration. Update as actual build is wired.

Port	Subsystem	Motor / sensor	Notes
1	Drivetrain front-left	11W Blue cartridge	direct drive, 4″ omni
2	Drivetrain front-right	11W Blue cartridge	direct drive, 4″ omni
3	Drivetrain back-left	11W Blue cartridge	direct drive, 4″ omni
4	Drivetrain back-right	11W Blue cartridge	direct drive, 4″ omni
5	Lift left	11W Red 100 RPM	direct drive to lower pivot, mirrored with port 6
6	Lift right	11W Red 100 RPM	mirrored with port 5; ganged commands
7	V5 claw	5.5W half-motor	standard V5 claw grip motor
8	Claw rotation (★)	5.5W half-motor	worm gear 36:1 to claw axis
9	Toggle rear-top	5.5W half-motor	2:1 chain to flex wheel; ganged with port 10
10	Toggle rear-bottom	5.5W half-motor	mirrored with port 9
11	IMU	VEX V5 IMU	chassis orientation + heading
12	Pot V2 (claw rotation angle)	analog in	reads claw rotation position to ~1° resolution
13	Pot V2 (lift angle)	analog in	reads four-bar lift angle for auton repeatability
14	Limit switch (lift REST)	digital in	auton homing reference at REST position

Build log (template)

Each build session adds an entry: date, team members, what was attempted, what worked, what didn't, decisions made.

Build log entries go here. Suggested first entry: “Tower height + arm length committed at 7″ / 9″ (working assumption). Cardboard mock-up of arm-over-tower clearance verified. Worm gear stage prototyped on bench; rotation speed measured at ~28 RPM under no-load (acceptable for in-cycle orientation use).”

Engineering notebook references

Coming soon. Cross-references to EN4 entries that document each design decision. Examples: “Rotating claw DOF justification: see EN4 p. XX.” “Worm gear ratio bench-test: see EN4 p. XX.” “Dual-wheel rear toggle 2-point grip rationale: see EN4 p. XX.” “Tower-vs-arm geometry trade-off: see EN4 p. XX.”