Fresamento Concordante e Discordante em Fresadora Convencional Parte 4

Summary

In this video, the presenter explains and demonstrates two milling strategies: 'concordante' (climb milling) and 'discordante' (conventional milling), providing insights into their advantages, disadvantages, and effects on material finish. The video is tailored for beginners, particularly those new to CNC routers or milling processes, highlighting how machine power, cutting direction, and tool choice can impact performance and results. Through hands-on demonstrations, the speaker shows how these strategies influence finish quality and tool behavior, offering valuable tips for optimizing milling techniques and achieving better results in production.

Takeaways

• 😀 *Climb milling* (concordante) advances the piece in the same direction as the cutter rotation, resulting in better surface finishes but requiring a machine with higher power to avoid material pulling or tool breakage.
• 😀 *Conventional milling* (discordante) advances the piece against the cutter's rotation, leading to less vibration and being suitable for less powerful machines, but often resulting in poorer surface finishes.
• 😀 For a better surface finish, *climb milling* is recommended, but it requires a more powerful machine to handle the material removal effectively.
• 😀 When performing *conventional milling*, the process may result in rougher finishes and burrs, which can be cleaned up afterward using tools like a file.
• 😀 A common strategy is to first perform a roughing cut (desbaste) and then finish with a *climb milling* pass for a smoother surface.
• 😀 Beginners often struggle with *climb milling* and *conventional milling*, so it's important to understand machine dynamics and correct any play or backlash in the machine for better results.
• 😀 Be mindful of machine play (folga) and consider adjusting strategies to avoid issues such as the piece moving during milling or the cutter pulling too much material.
• 😀 In *climb milling*, the cutter moves in sync with the machine's rotation, which can cause material to be pulled more aggressively if the machine has insufficient power.
• 😀 During *conventional milling*, the cutter works against the material, providing a more stable cutting action but can lead to poorer surface quality and increased wear on the machine.
• 😀 The video emphasizes the importance of choosing the correct milling strategy for the machine's power, suggesting *climb milling* for higher-end machines and *conventional milling* for lighter or simpler machines.

Q & A

What is the main focus of the video?

The video primarily focuses on explaining two types of milling strategies—concordante (conventional milling) and discordante (climb milling)—and how to apply them effectively in CNC router operations.

What is the difference between concordante and discordante milling?

In concordante milling, the piece is advanced in the direction of the cutter's rotation (clockwise), which gives a better finish but can be unstable on low-power machines. In discordante milling, the piece moves against the rotation (counterclockwise), reducing vibrations and stabilizing the process on lower-powered machines, though it may result in a poorer finish.

Why is concordante milling more suitable for high-power machines?

Concordante milling is more suitable for high-power machines because it requires the cutter to push into the material, which can pull the workpiece off or break the cutter if the machine is not powerful enough. High-power machines can handle this force more effectively.

What are the advantages of discordante milling?

Discordante milling has the advantage of reducing vibrations and providing more stability for lighter or less powerful machines, preventing the piece from being pulled off the bed during cutting.

What are the main disadvantages of discordante milling?

The main disadvantages of discordante milling include producing a poorer surface finish, with chips sticking to the workpiece, and requiring additional cleaning or finishing processes.

What should operators be mindful of when using discordante milling on low-power machines?

Operators should be mindful of the machine's capabilities, as discordante milling can be too aggressive on underpowered machines, leading to rough finishes and potential issues with chip removal. Adjusting cutting parameters and using smaller depths of cut can help mitigate these challenges.

How can a CNC operator improve the finish of a piece after using discordante milling?

After using discordante milling, a CNC operator can perform a finishing pass using concordante milling, which provides a smoother surface and eliminates the rough edges or burrs left by the discordante cut.

What role does machine play (folga) in CNC milling?

The machine's play (folga) refers to the tolerance or looseness in the machine's moving parts. It is important for operators to understand this play, as it can affect the quality of cuts, especially when using discordante milling. Excessive play can cause the cutter to slip or pull the workpiece, leading to inaccuracies.

How can beginners avoid problems when starting with CNC milling?

Beginners should focus on understanding machine tolerance, avoid using too much material removal with low-power machines, and use appropriate milling strategies (e.g., roughing followed by finishing) to achieve optimal results. Practicing with lower cutting speeds and lighter cuts can also help avoid common issues.

Why is it important to understand the cutting direction (concordante vs discordante)?

Understanding the cutting direction is crucial because it affects both the finish and the stability of the milling operation. Choosing the correct direction helps prevent damage to the machine or workpiece, especially in machines with limited power or precision.