OEM Cross-Flow Fan Customization: 40,000 Side Plates a Year

What the HVAC OEM needed

A high-volume HVAC OEM needed a cross-flow fan customization covering 40,000 side plates a year, starting with a batch of 8,000.

The problem was mechanical rather than aerodynamic. They wanted our 50150 series fan, with its 50mm wheel, inside their existing chassis. Unfortunately their mounting pattern does not line up with our standard housing.

Consequently this cross-flow fan customization replaces a standard component with one built to their dimensions, rather than changing how the fan performs.

• A mounting plate envelope of 70.8 by 73.2mm.
• Material thickness of 1.2mm.
• A unique hole pattern, taken from their own drawings.
• Lastly, manufacturing tolerance to GB/T1804-v.

They also asked one question that shapes the whole project. Could a sample be produced within a week?

Alongside that, they wanted firm answers on tooling time, the schedule for the first 8,000 units, the NRE charge and a production unit price. Frankly, those are the questions a buyer asks when a program is real.

Delivering the cross-flow fan customization fast

Here the ran as light development, meaning we changed a proven platform rather than building a new fan. That classification is what made the timeline possible.

Our engineers began by reading the customer CAD files, to fix the exact mechanical interface the new plates must meet.

How the one-week sample was met

Here is the crux. Hard tooling for a stamping die takes several weeks, yet the customer wanted parts in seven days.

Rather than compress the tooling, we simply split the two apart. Using the final CAD data, our team laser-cut and formed the plates from 1.2mm sheet steel.

That gives accurate, working prototypes. Consequently the customer fit-tested them in their own assembly inside a week, while the production tooling ran on its own schedule.

Recording the design

Meanwhile we issued new part numbers for the right and left plates, and captured the formal design in approved drawings.

That paperwork became the basis for the quote, covering tooling and the 40,000-unit yearly volume. In short, it gave the customer the clarity they asked for.

None of this is glamorous engineering. Even so, it is exactly what a high-volume OEM needs from a supplier during a launch.

Technical Specifications

Two part numbers appear below, one for each hand. Left and right plates need separate tools, which is why the tooling discussion matters as much as the drawing.

Technical Documentation

Final Mechanical Drawing: LW-C09-50-01
This is the final approved 2D mechanical drawing for the custom right-side mounting plate, part number LW-C09-50-01, required by mechanical engineers for system integration and quality inspection.

Here the cAD rendering illustrates the final assembly of the customized side plates with the standard 50150 cross-flow fan housing, used by design engineers to verify fit and clearance before production.

This CAD view shows the dimensional verification of the client-specific mounting interface, a critical step before releasing the design for tooling.

Why a high-volume OEM chose us

For a high-volume OEM, the supplier process matters as much as the part. In this case, four things counted.

• Samples that do not wait for tooling. A one-week deadline was the real test of this cross-flow fan customization. Producing functional prototypes by rapid manufacturing, independently of the tooling schedule, is part of how our NPI process works, against modification cycles that run 12 to 18 months elsewhere.
• Costs quoted, not estimated. The customer asked for development cost and tooling time, and received a clear proposal. Our Ningbo supply chain for stamping, tooling and finishing is what allows a firm quote rather than a range.
• A price that works at 40,000 units. At this volume, component cost drives profitability outright. Producing the motor and the impeller ourselves means that cost is set by our own process rather than by what a supplier chooses to charge us.
• Drawings that bind production. The whole job runs on paperwork. Since the CAD files and drawings are clean and signed off, the part we prototype is the part we ship, which leaves procurement and quality nothing to guess at.

Browse our cross-flow fan range, or the cross-flow impeller section for component supply. General tolerance grades follow ISO 2768 internationally.

Questions about custom tooling

How long did the first 8,000 units take after sample approval?

The prototype arrived in seven days. Once confirmed, the cross-flow fan customization moved to hard tooling. Stamping die fabrication and testing took roughly four weeks. After the purchase order landed, the first 8,000 units were built and ready to ship within 30 to 35 days, which is our standard for industrial make-to-order work.

Was there an NRE charge, and is that normal?

Yes, a one-time charge covering design and fabrication of the custom stamping dies. For a cross-flow fan customization of this kind, our NRE typically falls in the USD 12,000 to 40,000 range. For strategic partners with high-volume forecasts, we credit up to half of it back against future production orders.

You supplied plates without a motor. Do you offer motorised versions?

Yes. This customer supply chain needed housing components only, though the standard LWCD-50150 is available as a complete motorised assembly. That comes with either an AC shaded-pole motor or a variable-speed EC motor on our SmartEC platform. A factory-integrated unit is balanced and performance-tested to AMCA 210/211.

Why cut samples rather than rush the tooling?

Because rushing a die usually produces a worse die, and it still takes weeks. Laser-cutting from the same sheet gives a part that is dimensionally right for fit-testing, which is what the customer needed at that stage. Meanwhile the tooling proceeds properly, and neither activity blocks the other.