1. Fix the Spring Box at the center of the wooden headrail
2. Mount the V4 Cord Base units symmetrically on both sides
3. Route cords from the Spring Box through the V4 Cord Base
4. Guide cords downward through the bamboo Roman shade body
5. Secure cords at the bottom rail using the Cord Bundler
6. Fine-tune final tension via the Cord Bundler

Cordless Spring Selection Guide（Taking L4-2 as an Example）

Proper Cordless Spring selection is based on two key parameters:
total shade weight and shade width.

Cordless Spring System Architecture

• Spring Box – constant force energy and balance module
• V4 Cord Base – cord routing and load distribution interface
• Cord Bundler – bottom-rail fixation and tension adjustment

The Spring Box is installed centrally on the headrail.
Cords extend from both ends, pass through the V4 Cord Base,
and continue downward to the bottom rail,
where the Cord Bundler secures and adjusts final tension.

The Core of the Cordless Spring: Constant Force Spring Box

The Spring Box uses a constant force spring to maintain near-uniform output
throughout the entire lifting range.
This minimizes uneven lift, mid-height drift, and excessive pull force.

The housing is manufactured from engineering-grade POM,
offering low friction, dimensional stability, and long service life.
The flat-profile geometry integrates naturally with wooden headrails
used in bamboo Roman shades.

Model Example

The L4 Spring Box measures approximately
168.5 × 38 × 21.5 mm,
making it suitable for compact bamboo Roman shade constructions.

Cordless Spring Configuration Options

Spring Thickness

• 0.09 mm
• 0.10 mm
• 0.11 mm

Cord Quantity

• 2-cord system
• 3-cord system
• 4-cord system

Spring thickness is selected according to shade weight,
while cord quantity is determined primarily by shade width.

Frequently Asked Questions (FAQ)

Q1: How do I choose the correct Cordless Spring model?

Selection is based on total shade weight and finished width.
Spring thickness defines lifting force, while cord quantity ensures
balanced load distribution across wider bamboo Roman shades.

Q2: Can one Cordless Spring system fit different bamboo materials?

Yes. The L-Series Cordless Spring platform supports a wide range of bamboo
and fabric combinations by adjusting spring thickness and cord count
without changing the system layout.

Q3: Why is constant force important for bamboo Roman shades?

Bamboo Roman shades experience changing load as material stacks during lifting.
A constant force Spring Box maintains stable output,
preventing drift, uneven lift, and inconsistent hand feel.

Q4: What role does the V4 Cord Base play in system performance?

The V4 Cord Base controls cord routing and load symmetry.
It actively reduces left-right force imbalance caused by width,
material variation, or installation tolerance.

Q5: Is on-site adjustment possible after installation?

Yes. Final tension can be adjusted at the bottom rail
using the Cord Bundler, eliminating the need for spring replacement
or re-routing cords during installation.