How to Design Thin-Walled CNC Parts for Robotics Without Deformation: 3 DFM Tips

Created on 09.26

For mechanical engineers, design engineers, and procurement managers in robotics & automation R&D, thin-walled CNC parts (like robot arm housings, sensor enclosures, or transmission components) are a double-edged sword. They’re essential for lightweight, compact robotics designs—but deformation during CNC machining often leads to rework, delayed prototypes, and wasted costs. The solution? Smart Design for Manufacturability (DFM) practices. Below are 3 key DFM tips to keep your thin-walled robotics parts straight, plus how Marigold Rapid (www.marigold-rapid.com) supports seamless production.​

1. Keep Wall Thickness Uniform (And Within Machinable Ranges)​

Uneven wall thickness is the top cause of deformation—thicker sections cool slower than thinner ones during machining, creating internal stress. For robotics thin-walled parts:​

Stick to 1–3mm thickness: This is the “sweet spot” for most robotics materials (aluminum 6061, stainless steel 304) and CNC machines. Thinner than 1mm risks warping; thicker than 3mm adds unnecessary weight (bad for robot mobility).

Minimize thickness differences: If you need a thicker boss (e.g., for mounting holes), keep the transition gradual (slope or fillet) instead of sharp—this reduces stress buildup. For example, a robot sensor enclosure with a 2mm main wall should have a boss no thicker than 4mm, with a 3mm fillet transition.

2. Add Strategic Reinforcement Ribs (Without Overcomplicating)​

Reinforcement ribs boost rigidity without increasing overall thickness—but poor rib design can cause more harm than good. Follow these rules for robotics parts:​

Rib size matters: Make ribs 0.8–1x the wall thickness (e.g., 1.6–2mm ribs for a 2mm wall) and 2–3x the wall height. Too thick, and ribs will cause sink marks; too thin, they won’t add strength.

Space ribs evenly: Keep rib spacing 20–30mm apart. For a long robot arm housing (e.g., 300mm long), 10–15 evenly spaced ribs prevent bending during machining.

3. Optimize Feature Placement (Avoid Stress Hotspots)​

Holes, cutouts, or notches in thin walls create stress hotspots that lead to deformation. For robotics CNC parts:​

Keep holes away from edges: Hole centers should be at least 1.5x the hole diameter from the wall edge. A 5mm hole in a 2mm wall needs at least 7.5mm of space from the edge—critical for robot mounting brackets that need hole strength.

Avoid small cutouts in large thin sections: Instead of a 10mm cutout in a 200mm-wide thin wall, split the section with a small rib to distribute stress. This works well for robot base enclosures with cable access cutouts.

How Marigold Rapid Helps You Get Thin-Walled Robotics Parts Right​

At Marigold Rapid, we don’t just machine thin-walled robotics parts—we help you design them for success. As a one-stop full-process integrated manufacturer, our DFM engineers review your designs for free before machining, flagging deformation risks (like uneven walls or poorly placed ribs) and offering fixes.​

Our fast response means you get DFM feedback in 24 hours—no delays to your robotics R&D timeline. And with SGS certification (ISO9001 and 13485), our CNC machining process (using high-rigidity machines and precision clamping) ensures your thin-walled parts stay straight, even for small-batch prototype runs.​

Whether you’re designing a lightweight robot arm housing or a compact sensor enclosure, we flexibly adapt to your material and design needs—no deformation, no rework, no headaches.