JLCCNC Blog

Manufacturing Solutions

Rapid Prototyping Guide: Processes Compared and How to Choose the Right Method for Manufacturing

What Is Rapid Prototyping (AI generated) Various rapid prototyping parts including 3D printed, CNC machined, and sheet metal components on a workshop table. Rapid prototyping is a manufacturing approach that produces physical parts directly from CAD data within hours or days, enabling engineers to quickly validate design, fit, and function before full-scale production. Modern shops use several methods under this umbrella. 3D printing, CNC machining, and sheet processes all fall into the rapid prototyp......

Jul 25, 2026

Surface Finishing Processes

How to Read Surface Roughness Symbols: Drawing Examples & ISO Guide

Key Takeaways Surface roughness symbols define the required finish for individual features on an engineering drawing. ISO 1302 provides the standard symbols used on most international technical drawings. A surface finish callout can include the roughness value, machining requirement, lay direction, and supplementary notes. Ra is the roughness parameter specified most frequently, although Rz is common for some functional surfaces. Correct interpretation of a callout helps match the surface requirement ......

Jul 25, 2026

CNC Machining Fundamentals

Chip Thinning in CNC Machining: Formula, Feed Rate & Calculator

Key Takeaways Chip thinning lowers actual chip thickness at narrow radial engagement. Feed per tooth must rise to maintain the intended cutting load. The formula connects cutter diameter, stepover, and engagement geometry. A calculator applies the correction before feed-rate programming. The method suits partial-width cuts rather than full-width slotting. Chip thinning takes place when a cutter takes a narrow stepover in order to make each chip thinner than the programmed chip load suggests. Understan......

Jul 24, 2026

Design Tips & Best Practices

Differences Between Tolerance and Allowance

Key Takeaways Tolerance controls the allowable variation of a single dimension, while allowance is the intentional difference between two mating parts that determines the type of fit. Tolerance and allowance are closely related but describe different aspects of dimensional control. Tolerance defines the acceptable variation of a single dimension, while allowance defines the intentional difference between mating parts to achieve a required fit. Confuse them and you end up with parts that either won't a......

Jul 22, 2026

CNC Machines & Equipment

Complete Guide to Custom Fixturing: Design Principles & Workholding Methods

Key Takeaways Custom fixturing securely locates and supports challenging parts. Dedicated designs improve positioning consistency across machining cycles. Planned clamping limits movement and workpiece distortion. Better tool access can lower multi-sided setups. Repeated production justifies the initial fixture expense. Inspection and validation prepare the fixture for reliable production. With custom fixturing, manufacturers have dedicated control over part location, support, and clamping in situatio......

Jul 22, 2026

Surface Finishing Processes

Surface Roughness: Chart, Ra Values, Units & Applications

Key Takeaways Surface finish in machining directly influences how a part seals, slides, fits, and wears during service. Ra is the roughness value most commonly specified on manufacturing drawings. Even the same/similar machining techniques can produce different finishes after changing tooling, cutting data, and material. CNC Milling, CNC turning, grinding, and honing each leave their own surface pattern. A surface roughness chart gives engineers a practical reference during design and process planning......

Jul 22, 2026