The Curl — the hooked-approach drill

Drag the base handle

You do not aim the tip. You drag the base plate; a two-bone arm carries the motion out to a fixed-distance station, and the plate's overtravel adds a hook to the final approach. The target is hidden — the only guide is the warmer/colder strip, which reads the tip's curved approach (its end-tangent) against a target hook. Match it, then hold to lock. Left-drag the plate (forgiving grab) · right-drag or hold Space to orbit · wheel zooms.

Curl alignment

— pick a target —

left-drag the pink plate (forgiving grab) · right-drag / Space+drag to orbit · wheel zoom · the target is hidden — read the strip

Dock = straight vector (match a direction). Curl = curved vector (the tip must arrive hooking — its end-tangent bends toward the target rather than pointing straight at it).

press New target to begin

Not aligned
hold inside the cone to lock

0LOCKS

—BEST ERROR

—LAST LOCK

Press New target. A hidden hooked approach appears. Drag the base plate until the strip reads "warm", then "locked".

Why did I miss?

Error is split so a miss is legible — is your curl wrong (the hook direction), or your placement (the tip isn't at the fixed station)?

Assists & options

Reveal target hook (training wheels)

Show tip tangent Show linkage

Show tolerance cone (on lock approach)

Keyboard controls

Click the 3D view first (it takes focus). ←→↑↓ orbit · Home reset view · wheel zoom.
Drag the pink base plate to drive the arm. The tip's curved approach is the referent of all feedback — always.

What this drill teaches

One sub-skill only: approach vector, curved (the tip must hook, not just point). Depth is fixed — the tip always reaches the same station distance; there is no depth axis here (that's the Contact drill's job) and no drift. Indirect control: you drive a base plate, IK carries the arm to the station, and how far you drag past the arm's comfortable reach bleeds into a hook on the final segment's tangent — so the same drag gesture that places the tip also curls it. Max two uncertainty sources: hidden target + indirect linkage.

The lesson: a straight approach (Dock-style) will place the tip near the station but the tangent will read cold, because the winning approach curls up-and-toward rather than pointing straight in. You have to overdrive the plate slightly past the target's own position to buy the hook the target actually wants.