Roll even coils

Before you can build, you need to roll. Sounds simple. It's not.

Roll ten coils of equal diameter (about 1 cm thick) and roughly 20 cm long each.

What "even" means

• Same thickness along the entire length (no thin middles, no fat ends)
• Round cross-section, not flat or oval
• No cracks or dry spots

Technique

• Start from the center and roll outward with spread fingers
• Use your palms, not just your fingertips
• Lift and re-center if the coil starts flattening

Line all ten up side by side. They should look like siblings, not strangers.