CNC Spring Machine Buying Guide: Cam vs Camless by Wire Diameter

If you are specifying a spring machine for production, the first real question is never about brand. It is about wire diameter range and whether you need cam or camless architecture. Get those two right and the rest of the spec sheet almost falls into place. Get them wrong and you spend the next three years fighting your equipment.

I have been on the floor of enough factories to see this play out. A shop buys a heavy-duty cam machine for 0.3 mm wire because the brochure looked impressive. Six months later they are still hand-feeding fine wire and complaining about surface marks. Same the other way: someone runs 3.5 mm spring steel through a camless forming machine designed for electronics, then wonders why the servo drives overheat. The machine was not wrong. The match was wrong.

Why wire diameter drives the architecture decision

Wire diameter dictates three things simultaneously: the torque your forming slides need, the feed roller pressure you must hold, and the springback the machine has to overcome. Below 1.0 mm, the wire is light, springback is low, and the production rate target is high. Above 2.0 mm, the opposite is true.

Cam machines use mechanical cams to drive the curling, pitch, and cutting slides. They are workhorses for heavier wire because the cam profile delivers raw torque and the mechanical repeatability is locked into the cam itself. The downside is that changing wire diameter or part geometry usually means swapping cams, which is downtime.

Camless machines replace the cams with independently controlled servo axes. Setup changeover is software-driven, so going from one part to another is a matter of loading a new program. That is why camless dominates the fine-wire and high-mix environment.

A practical cross-reference table

Here is how I typically help buyers map their wire range to a machine family. The numbers below reflect what we ship out of the Dongzheng facility in Dongguan and what we see running in 15+ countries:

• HSM-CNC08 Spring Coiling Machine: 0.08 - 1.0 mm, camless, ideal for electronics and micro-springs

• HSM-CNC1008 Camless Spring Machine: 0.1 - 1.0 mm, camless, compact footprint

• HSM-CNC20 Cam Spring Machine: 0.2 - 2.0 mm, cam, our flagship with 100+ units running globally

• HSM-CNC1025 Camless Spring Machine: 0.2 - 2.5 mm, camless, higher mid-range

• HSM-CNC30 Spring Coiling Machine: 0.8 - 3.0 mm, hybrid drive

• HSM-CNC1045 Camless Spring Machine with wire rotatory: 1.8 - 4.5 mm, camless, heavy wire

• HSM-CNC40 Cam Spring Machine: 1.8 - 4.5 mm, cam

• HSM-CNC60 Cam Spring Machine: 2.0 - 6.0 mm, cam, available with or without wire rotatory

The overlap zones (around 1.8 to 2.5 mm, and again around 1.0 mm) are where buyers often overthink. If your part mix is stable and your batches are long, the cam machine will give you longer tool life and lower cost per part. If your mix changes weekly, the camless machine will give you back the hours you lose on cam swaps.

What the axis count actually buys you

A 2-axis coiler handles simple compression and tension springs. Add axes and you unlock torsion geometry, 3D wire forming, and complex hook shapes. For automotive seat frames, oil seal springs, and double torsion products, you are realistically looking at 3-axis minimum, often 4 or 5 axis 3D CNC bending configurations.

This is where the keyword really earns its place. A high speed 3D CNC wire bending machine for oil seal spring production is not the same tool as a 2-axis coiler. Oil seal springs are conical, often with variable pitch, and they need a wire rotatory axis to lay the wire into the cone geometry without scarring the surface. Our HSM-CNC1045 with wire rotatory handles 1.8 to 4.5 mm in this class, which is exactly the seat-frame and oil-seal range.

For double torsion springs, the 3/4/5 axis 3D CNC bending for double torsion spring product becomes essential. Two torsion legs on the same wire, with controlled leg angle and body length, is not something a 2-axis cam machine can hold to ±0.01 mm consistently. A Vietnamese customer running the HSM-CNC20 since 2010 reported sustained ±0.01 mm accuracy and a 35% daily output lift within eight months of installation. That kind of drift-free performance over 15+ years is what multi-axis synchronicity is supposed to deliver, and it is rarely the 2-axis machine that gets you there.

Real data from the field

A few reference points that might help your own evaluation:

• Vietnam: 40+ machines running, the HSM-CNC20 is the volume platform

• Brazil: 10+ units, a 2022 buyer of two HSM-CNC20 machines has never opened a service ticket through our WeChat support group

• Indonesia and Korea: 5+ units each, mostly in the electronics tier

• Shenzhen: a 2026 order of two HSM-CNC20 plus an HSM-CNC08 came specifically because the customer's setup technician had run competing brands and asked for Dongzheng by name, citing stability, durability, and ease of adjustment

• Vietnam, March 2026: a buyer who already owned another brand saw an HSM-CNC20 in operation at a peer factory and ordered one the same quarter, citing the visible difference in forming stability

The Brazil case is worth pausing on. Zero service events across four years on two machines is unusual and it is not an accident. It reflects how the cam profile is ground, how the feed rollers are aligned at the factory floor, and how the Windows-based controller is configured before crate.

The simple decision framework

If your wire is under 1.0 mm and your batches change often, start with the HSM-CNC08 or HSM-CNC1008 camless platform.

If your wire is 0.2 to 2.0 mm and your batches are long, the HSM-CNC20 cam platform is the proven path. It is the machine 100+ factories have standardized on and the one with the deepest field track record.

If your wire is 2.0 to 6.0 mm, you are in HSM-CNC60 territory, and the wire rotatory option matters more than any other spec on the sheet.

If you are doing 3D wire forming, oil seal springs, or double torsion geometry, you are looking at camless multi-axis platforms like the HSM-CNC1025 or HSM-CNC1045 with wire rotatory.

The fastest way to waste money on a spring machine is to choose by brochure photography. Choose by wire diameter, batch length, and geometry complexity, then validate the axis configuration against the actual part drawing.

One question for your floor

Before you finalize the spec, walk to your production line and ask your setup technicians one question: "How many different parts do you change over to in a typical week?" Their answer will tell you whether cam or camless belongs in your factory, regardless of what any sales sheet is telling you.