User Guide

How to Use the Contour Gauge

Step-by-step instructions for assembling and using the modified contour gauge for bamboo joinery.

Quick Start

1

Calculate

Use the calculator to determine sliders needed for your bamboo size

2

Assemble

Insert tube sliders into the eight-shaped cases

3

Contour

Press against bamboo and transfer the profile

1

Measure Your Bamboo

Determine the diameter of the bamboo culm you need to join.

  • Use a caliper to measure the outer diameter at the joint location
  • Record the measurement in millimeters
  • Note: This tool supports bamboo sizes from ∅70mm to ∅100mm
2

Calculate Sliders Needed

Use the slider calculator to determine the correct number of tube sliders.

  • Go to the Calculator page
  • Enter your bamboo diameter (e.g., 90mm)
  • Set slider diameter (default: 2.0mm) and spacing (default: 1.0mm)
  • Note the "Sliders needed" value for ≤1% error

Example: For ∅90mm bamboo with 2mm sliders and 1mm spacing, you need approximately 95 sliders for near-perfect coverage, or 90 sliders for a 4.5% error margin (acceptable for most joinery).

3

Assemble the Sliders

Insert tube sliders into the eight-shaped cases.

  • Take the required number of 2mm tube sliders
  • Insert each slider into an eight-shaped case
  • Ensure smooth sliding movement — the slider should move freely but not wobble
  • Arrange slider assemblies in a circular formation matching your bamboo circumference
4

Attach Centering Mechanism

Install the SCH (Simple-Holder Centering) mechanism.

  • Place the TPU 90A centering ring around the slider assembly
  • The elastic material will press the bamboo and sliders into the center
  • Ensure the ring sits flush and applies even pressure
5

Position on Ohm-shaped Stand

Use the stand for single-user operation.

  • Place the ohm-shaped stand on a flat, stable surface
  • Insert the bamboo pole vertically into the stand
  • Ensure the bamboo is secure and won't tip during contouring
6

Capture the Contour

Profile the bamboo cross-section for joinery.

  • Press the assembled contour gauge firmly against the bamboo surface
  • The sliders will conform to the bamboo's curvature
  • Hold steady for 3-5 seconds to ensure accurate profiling
  • Carefully remove the gauge while maintaining slider positions
  • Transfer the profile to your joinery template or directly mark the mating piece
7

Verify & Adjust

Check accuracy and make adjustments as needed.

  • Compare the transferred profile with the actual bamboo cross-section
  • Expected error margin: ~4.5% with 90 sliders (acceptable for joinery)
  • For higher precision, increase slider count per calculator recommendations
  • Clean sliders after each use to maintain smooth operation

Pro Tips

Use the stand for solo work — it eliminates the need for a second person to hold the bamboo steady.

Always calculate sliders before assembly — using too few will result in gaps and inaccurate profiles.

Store the gauge in a dry place. TPU can degrade with prolonged UV exposure.

If a slider gets stuck, gently wiggle it free. Don't force it — the case could crack.