Challenges of CNC Machining Honeycomb Panels
February 25, 2022
Honeycomb cores are a popular choice for applications throughout many industries, including aerospace, aeronautic, automotive, naval, and others. The layered hexagonal structure creates high strength and excellent stiffness to weight ratio. However, honeycomb core panels are notoriously difficult to machine due to the weak rigidity present in the in-plane direction of the cellular materials. Due to the challenges in machining honeycomb panels, many engineers choose materials and structures less suited to their planned use or waste time and resources inefficiently machining honeycomb core.
At Upland Fab, we specialize in honeycomb machining and honeycomb CNC cutting and milling. We can help you understand the intricacies of machining honeycomb composites and honeycomb panels. We also have the machining capacity and industry expertise to complete your honeycomb CNC cutting project for you.
Why Can Honeycomb Panels be Difficult to CNC Machine?
Many of the characteristics that make honeycomb core ideal for an extensive range of applications make it extremely difficult to machine. The complex shape of the honeycomb composites requires equally intricate practices that are unlike any other CNC machining process. Additionally, honeycomb cutting often requires an extensive amount of post-processing to remove partially released flags along the core walls’ machined edges.
Common Challenges of Honeycomb Machining
Exact challenges, cutting parameters, and other aspects of honeycomb CNC cutting will depend on the nature of your application. However, several common challenges are apparent for any honeycomb machining process, such as:
- CNC cutting components are damaged during machining due to inexact application
- Honeycomb core is damaged by out-of-date or poorly maintained cutting equipment
- Honeycomb core must be kept immobile, or vibration caused during machining will impact the cut’s depth and accuracy
- Using incorrect cutting tools for honeycomb machining
- Machinist not having prior experience cutting honeycomb with CNC machining methods.
Other challenges may present themselves depending on your specifications for the finished honeycomb core. Consult with an expert machinist shop to address your specific project’s unique challenges.
The Properties & Challenges of Honeycomb Composites
Honeycomb core can be comprised of varying materials to meet the needs and guidelines of your industrial application. Each material offers various performance qualities, strengths, and challenges during machining. Contact us if you are unsure which honeycomb composite is best suited to meet your specifications.
Aluminum Honeycomb Core
Aluminum honeycomb creates maximum stiffness with the highest strength-to-weight ratio of any other option on the market. Aluminum resists corrosion, absorbs no moisture, and is ideal for industrial, transportation, or architectural applications.
Aluminum is also a softer material, though, making it difficult to machine. Special attention must be given to the temperature of the material during the machining process, or a gummy buildup may form.
Aramid Honeycomb Core
Honeycomb cores made from Aramid fibers are manufactured from Meta-Aramid or Para-Aramid to produce a heat-resistant, nonmetallic honeycomb composite. Honeycomb panels made from Aramid (including Nomex and Kevlar) are high-strength options often found in racing, defense, and aerospace applications.
Aramid honeycomb CNC cutting is a delicate process that requires extreme precision, patience, and experience. The core must remain stabilized and motionless throughout machining, particularly when machining Nomex materials.
Thermoplastic Honeycomb Core
Honeycomb cores formed from thermoplastic materials, often polycarbonate or polypropylene, display high resistance to corrosion. Paired with a unique cell structure, thermoplastic honeycomb cores are ideal for sandwich panels, molded parts, wind tunnels, and many other applications.
Thermoplastic honeycomb cores are often damaged during cutting, making them unusable for most applications. Working with an expert machinist will help you avoid this outcome.
The Best Cutting Tools & Methods for Machining Honeycomb Core Panels
A critical component for successful honeycomb machining is to apply correct and properly maintained tools. All cutting tools for honeycomb CNC machining must be made of hard materials and kept sharp to produce the necessary complex hexagonal structure in the honeycomb core panels. CNC machines and components that work best for honeycomb machining include:
- Milling cutters with polycrystalline diamond (PCD) tips
- Turning tools with PCD tips
- Flute cutters
- 5-Axis CNC machines
- Adjustable speed and feed rate to avoid melting resins
- And more.
Honeycomb machining often requires specialized cutting tools that cost more than standard CNC machine components. Working with an already outfitted machine shop is often more cost-effective. An experienced machinist partner also creates less room for error during the complicated honeycomb machining process.
Expert Honeycomb Machining from an Experienced Machine Shop
Upland Fab is an ISO 9001:2015 and AS9100 Rev D certified manufacturer of plastic and composite machined components, including honeycomb core made from various materials. We have earned our industry reputation for high-quality products and reliable services through our work with many industries. We understand the struggle of honeycomb machining, and we are here to support your efforts through hands-on experience and real-world knowledge. We work with you from beginning to end, using our industry-leading DPD/MBD system to ensure the right honeycomb core is produced the first time.