CNC Onsite continues to broaden popular yaw ring repair service across more wind turbine types

PRESS RELEASE

High demand drives expansion of patented up-tower solution – innovation to be showcased at Husum Wind 2025 at stand 3C32

Vejle, Denmark, 10 September 2025 – CNC Onsite, the Danish mobile machining expert, is extending its patented yaw ring repair service to more wind turbine platforms as demand for the up-tower solution continue to grow. The service, proven across onshore and offshore wind farms, helps owners avoid costly yaw ring replacements while cutting downtime, emissions, and safety risks.

The yaw ring – or yaw gear rim – keeps turbine blades facing into the wind. If its teeth wear down or break, replacement traditionally involves cranes, transport, and the disassembly of the nacelle, with high costs and lengthy downtime. CNC Onsite’s compact, modular machine enables precision repairs to be carried out inside the nacelle instead, restoring damaged yaw teeth within days.

A segment within worn down or missing yaw gear teeth

The repair process
CNC Onsite’s portable machine is transported in modules and reassembled inside the nacelle to operate within the confined space around the yaw ring. Working up-tower, the machine mills away the damaged section of the gear tooth to precision, leaving a pocket with exact dimensions. A prefabricated replacement tooth segment is then fitted securely into the cavity, returning the yaw ring to full functionality.

The process has often been compared to a dentist repairing a tooth — removing decay and inserting a perfectly shaped filling, but carried out on a giant scale, inside a turbine tower.

Demand for yaw ring repair rising

“Demand for our yaw ring repair has been remarkable,” says Soren Kellenberger, sales director and partner at CNC Onsite. “Even though the percentage of yaw rings being damaged is very low, it still adds up given the total number of wind turbines installed. Therefore we have added more turbine platforms this year, and more are on the horizon. This expansion means even more operators can extend the life of their turbines while avoiding the costs and carbon footprint of full replacement.”

Since launching in 2019, CNC Onsite’s patented repair method has been deployed across three continents, with more than 100 yaw ring segments – equivalent to 600 teeth – successfully installed.

Each repair not only avoids the heavy CO2 emissions associated with crane operations but also reduces health and safety risks linked to handling large turbine components.

Supported by its 2,000 m² technical center in Vejle, Denmark, CNC Onsite has continued to invest in engineering resources to adapt its repair system to different nacelle configurations and working spaces. This flexibility ensures the solution can be rolled out rapidly to additional turbine platforms.

The innovation will be presented at Husum Wind, 16–19 September 2025, where CNC Onsite will demonstrate at its stand 3C32 how its up-tower technology is helping keep turbines in operation longer, safer, and more sustainably.  

See Soren Kellenberger's interview with Uptime Wind Energy Podcast on yaw ring repair

About CNC Onsite

Headquartered in Vejle in Denmark, CNC Onsite designs and delivers high precision mobile machining for wind turbines including offshore foundations. Machinery built by CNC Onsite is designed to be flexible using its proprietary "building blocks" approach, which means machinery can be built to match a range of tasks. CNC Onsite serves the onshore and offshore wind energy sector delivering as standard solutions: machining of large diameter steel flanges and blade root ends; specialized repair services covering yaw ring, inserts in blade root, rotor lock, generator shaft, bearing housing and threaded holes. Removal and replacement of worn and broken bolts round off the offering.

 www.cnconsite.dk