In this era of high-speed computers, machine tools do more than just being a part of the manufacturing process.
Unlike cutting tools our forefathers had years ago, these ‘computer-controlled’ tools or CNC tools are mostly self-working, thus eliminating the dependency on tool operators’ skills and experience by miles This quickens the process, providing us with hundreds and thousands of similar high-precision parts in record time.
CNC machining is not a very new concept; it’s been here since the late 1940s. It started with the evolution of milling machining & lathes. Today, we have plenty of specialized CNC machine shops that can take care of your precision parts requirements, on-time and in-budget. The flexibility and productivity associated with CNC tools play a huge part in this.
Toronto citizens, before you jump on the process and directly after you decide on a machine shop (Toronto), it’s imperative you closely look through the machine tools you’ll be working with.
Overwhelmed? We can help you out. Take this post as your go-to guide for selecting the right tools for your CNC machined parts.
The first step is to assess the materials you’ve selected for the part and see if it is complementing the cutting or milling tools your partner machine shop is recommending to you.
While CNC machine tools can work on a large variety of materials, there are cases where the tool material is practically weaker than the part we’re hoping to build. The material type involved will greatly influence the material design, speeds and feeds required spindle-type, surface finish needed, and overall durability, precision and performance of the part.
Most of the milling and cutting tools are built using:
- Carbon steel (inexpensive variety; used for low-speed operations)
- Solid carbide (wear-resistant; mostly used for high-finishing)
- Ceramics (corrosion-head-wear resistant; mostly used for cast iron, superalloys and cast iron)
- High-speed Steel (top-quality, expensive materials, very durable; used on ferrous and non-ferrous materials)
Machine Tool Type Needed For The Process
Depending on the nature of the process - milling, cutting, grinding - you’ll have to select tools that best suit it. Some of the popular types include:
- Turning Centers (Lathe): Most popular; used for cylindrical shapes (both straight & rounded sides)
- Swiss Style Turning: Really fast and durable; mostly used to deliver high-precision parts in smaller quantities; a popular part of the aerospace and medical industries
- Turn-Mill Centers: Offer both turning & milling; used to create very large parts
- Metrology Machines: Used for quality checking and inspection
- Shaper: Comparatively smaller in size; is attached to the top of a fixed work-piece to give it the required shape
- 5-axis/7-axis machines: Very flexible, can move in 5/7 different direction; low set-up time
The Complexity of Machined Part
CNC machines are known for producing high-complex parts; however, it’s the tools that make it possible to cut that precisely, work that way.
Parts for highly-sensitive industries might require a special process, advanced machining, precision CAD, and high-quality CNC machine tools and spindles. Usually, horizontal or vertical lathes or milling machines with 5/7/8 axis do the most jobs here
Tool’s Current State
So you know what materials you’re going to work on and what tool is best suited for it. Next comes checking if the given tool is at its best. We’re not saying you have work with a fresh tool
every time; however, it’s imperative to know your tools are maintained well and do not fall short on required attributes to ensure high-performance.
It’s possible one of your CNC tools is losing its sharpness; some other is not fitting well with the work-piece. Perhaps the tools have worn off; they have had issues in the past.
The reason is simple - if your tools are non-performing, they can create issues in the process, wasting your time and money
Cost per Part - Your Budget
Last but not least, you’ve to consider what’s your budget for the part and for the entire CNC project. Considering there are both fixed (initial capital investment, loan interest (if applicable)) and variable costs (machine/labour/material costs, tooling costs, maintenance and services costs and overheads (if any)), you’ve to be very selective while choosing the best possible equipment for your project.
We suggest you look at your objectives and plan accordingly - can be long-term (where you’d most probably use durable tools that can ensure cent percent effectiveness) or short-term (for quicker, cheap projects). The overall idea is to select tools and processes that best suit your project type while being in budget.
This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.
© 2020 Norm Grimberg