What you need
- Two to four scrap parts
- Clamps
- Square
- Pencil arrows
Try it
- Dry-fit the parts.
- Draw arrows where pressure will push or pull.
- Clamp lightly.
- Check whether the actual movement matched the arrows.
Look closely
What changed?
Clamps can move pieces sideways, not just hold them still.
Make it easier
Use two straight boards only.
Try another way
Try a picture-frame shape and compare diagonal measurements.