# MiniMax H3 crank-slider prompt: keep both rod pivots attached

Brief one connected motion in which rotation becomes a small linear slider displacement. The connecting rod is an active constraint, not a decorative line between separately animated parts.

Original synthetic practice still, not a generated result. No model run has been performed.

Files: first-frame.png (1024×1024 actual first-frame input), first-frame.svg (editable geometric design source; do not upload as if it were PNG), prompt.en.txt / prompt.zh.txt, acceptance.blank.csv (all observations empty), task-definition.json and RIGHTS-REVIEW.txt.

## Generator

Use MiniMax H3 base image-to-video. Turn on Add end frame to expose First Frame, upload first-frame.png only, and leave Last Frame empty. Fast requires a pair and is not covered. Choose only options offered by the current interface; opening it does not submit.

## Starting state

The front-view diagram shows a wheel on the left, an off-center pin above and right of its hub, one long rod and a rectangular slider in a horizontal guide on the right. The rod joins that pin to the slider center. Both joint circles are visible.

The wheel hub and the horizontal guide stay fixed. Follow the off-center pin, both rod endpoints and the slider outline. In this starting sector, a small clockwise turn brings the pin closer to the rightmost wheel position and can move the slider modestly right; the input is not at a reversal.

## Steps

1. Identify both actual pivots in the PNG, rather than following the wheel rim or a decorative rod highlight. A replacement image needs visible connections and a guide aligned with the intended slider direction.
2. Keep the request within the initial crank sector. Do not add a full cycle, speed changes or a second mechanism until this one linked stroke can be inspected.
3. For a later result, compare a start frame, a frame with the largest rod-angle change and the ending. Check rod length and attachments before judging whether the overall machine looks convincing.

## Acceptance

- The wheel hub and horizontal guide remain fixed relative to the frame.
- The same rod connects the same off-center wheel pin to the slider at every visible stage.
- The slider travels within the guide without rotating, while the rod retains a coherent rigid length.
- The ending retains all connections and stops before a full cycle or a second stroke.

## Limits

The drawing supports a qualitative linkage-continuity exercise. It is not a measured stroke, motor design, engineering verification or an independently tested H3 result.

Read prompt.en.txt before submitting. No pass results or output video are included.