Cam vs Camless CNC Spring Machines: How to Choose the Right Wire Diameter Range

A Practical Selection Guide for Production Engineers

Most spring forming workshops eventually face the same question: when does a cam-based CNC spring coiling machine still make sense, and when should the budget go toward a camless spring machine? The answer depends almost entirely on three variables: wire diameter, part complexity, and changeover frequency.

Let's break this down using real machine data from the Dongzheng Spring Machine lineup, with 20+ years of manufacturing experience and 100+ HSM-CNC20 units running globally across 15+ countries.

What Cam and Camless Actually Mean in Spring Forming

In a cam spring machine, mechanical cams dictate the tool path. The cams are physical parts that must be physically swapped or adjusted to change the spring geometry. This mechanical approach delivers high speed and excellent rigidity for high-volume runs of the same part.

In a camless spring machine (also called a wire bender with full servo control), every axis is driven independently by servo motors. Tool trajectories are programmed in software, not hard-coded into metal. Setup time drops dramatically, and complex geometries become possible without custom cams.

The tradeoff: camless systems generally handle lower wire diameters than heavy cam machines, though newer designs are closing that gap.

Wire Diameter Coverage Across the Dongzheng Range

The full product line spans micro-wire medical coils up to heavy-duty garage door torsion springs. Here is how each model maps to a wire diameter window:

Model	Type	Wire Diameter (mm)	Key Feature
HSM-CNC08	Cam	0.08 - 1.0	Micro-electronic parts
HSM-CNC1008	Camless	0.1 - 1.0	Fast setup, micro wire
HSM-CNC20	Cam	0.2 - 4.0 (standard 2.0)	Flagship, 100+ global units
HSM-CNC1025	Camless	0.2 - 2.5	Mid-range flexibility
HSM-CNC30	Cam	0.8 - 3.0	Larger coil diameters
HSM-CNC40	Cam	1.8 - 4.5	Heavy-duty springs
HSM-CNC1045	Camless	1.8 - 4.5	Camless with wire rotation
HSM-CNC60	Cam	2.0 - 6.0	Thickest wire, with/without wire rotatory

Notice the pattern: for wires below 1.0 mm, both cam and camless options exist. For 1.8 mm and above, the HSM-CNC40 and HSM-CNC60 cam machines dominate in pure throughput. The HSM-CNC1045 camless fills the gap for shops that need servo flexibility on heavier wire.

When a Camless Spring Machine Pays for Itself

A spring job shop running 30+ different part numbers per month will spend hours every week on cam changes alone. A camless spring machine cuts setup time by roughly 50% in real production environments, because the operator loads a program instead of swapping mechanical parts.

This is especially relevant for medical spring product manufacturers, where lot sizes are small, traceability matters, and part geometries change frequently. A multi-axis camless machine can produce complex medical coils, including conical shapes and progressive pitch, in a single setup without manual intervention.

For electronic parts, a computer CNC spring former for electronic parts typically handles wire from 0.1 mm to 1.0 mm at very high speeds, well within the HSM-CNC08 or HSM-CNC1008 range.

When a Cam Spring Machine Still Wins

High-volume production of a single spring design is where cam machines remain king. The mechanical rigidity translates into faster cycle times and lower per-part cost. One Vietnamese customer running the HSM-CNC20 saw daily output increase by 35% within 8 months of installation, with repeatability holding at ±0.01 mm continuously since 2010.

The HSM-CNC60 handles wire up to 6.0 mm, which most camless machines on the market still cannot match reliably. Garage door springs, heavy automotive suspension components, and large industrial coil springs require this wire range and the kinetic energy that a cam-driven slide delivers.

Field Performance: What Real Customers Report

A Shenzhen buyer in 2026 ordered two HSM-CNC20 units plus one HSM-CNC08 after their setup technician had used various brands at previous factories. The technician specifically praised the machine's stability, durability, and ease of adjustment, which is the kind of feedback that comes from daily operator experience, not marketing material.

A Brazilian customer purchased two HSM-CNC20 units in 2022 and has never activated the WeChat-based maintenance service group, a strong indicator of machine reliability when the buyer has not needed remote support even once.

In Vietnam, a 2026 buyer initially purchased from another manufacturer, then switched to the HSM-CNC20 after seeing the production stability difference firsthand at a peer factory.

Quick Selection Framework

Use this rule of thumb when specifying a machine:

• Wire below 1.0 mm, high mix, small batches → Camless (HSM-CNC1008 or HSM-CNC1025)

• Wire 0.2 - 4.0 mm, high volume, single part focus → Cam (HSM-CNC20)

• Wire 1.8 - 4.5 mm, complex shapes, need wire rotation → Camless (HSM-CNC1045)

• Wire 2.0 - 6.0 mm, heavy industrial → Cam (HSM-CNC40 or HSM-CNC60)

• Wire 0.08 - 1.0 mm, micro-electronic precision → Cam or Camless (HSM-CNC08 / HSM-CNC1008)

Final Thought

The cam versus camless decision is rarely about which technology is "better" in absolute terms. It is about matching wire diameter, part complexity, and production volume to the right tool. For shops running both small medical coils and larger industrial springs, having one of each class may be the most cost-effective path.

What does your current production mix look like: high-volume single parts, or high-mix small batches? The answer will likely point you to one technology over the other.

---