From CAD to CNC Production: The Complete Guide

Computer-aided design (CAD) involves computers that help facilitate the formation, tweaking, operation, and analysis of the creation of an object. CAD is a crucial step in manufacturing, which lets you take the design to various technological manufacturing techniques, including injection molding, CNC milling, or 3D printing.

In the CNC machining phase, numerical control technology oversees the machine’s operation. CNC machinists use G-code as the language to operate a CNC machine, which helps manage the speed, coordination, and feed rate of the CNC machine. Getting a part machined back in the day involved steps like asking for a quote from a machine shop, waiting for two to five days to receive a response, and still not being entirely sure that the offer you received was the best in the market.

CNC pricing is typically multifaceted and subjective. Each supplier will have different thoughts on the difficulty involved in manufacturing a specific component. Price ambiguity was always prevalent until the supplier had machined it. However, with reliable online manufacturing platforms that use AI-powered automatic systems, you can now receive a quote in no time. AI systems accept input, such as part geometry, quantity, material, and other manufacturing requirements, to accurately estimate the manufacturing costs of a part in real-time.

Preparing your CAD Files 

CAD Drawing being prepared for CNC machining.

The first and foremost step is to prepare your CAD files to give instant CNC pricing to the client. This step is crucial because the CNC costs are ambiguous and typically subjective. Suppliers often differ on the level of skill required to manufacture a part. Until they machine it, no supplier can assuredly tell you the pricing. In earlier times, the ability and skill level of the machinists immensely influenced the machining expenses. However, pricing today is provided using an AI-driven sourcing program that closely resembles the stock market. 

AI-powered online manufacturing platforms have begun implementing AI-driven automatic systems that help deliver a quote in real-time. You only require information such as the part’s geometry, quantity, and material to provide a pricing quote instantly. Also, if you don’t have the resources to outsource 3D modeling tasks, you can design your CAD files in a 3D modeling software. With SelfCAD, you don’t need to have previous experience in design to be able to create your designs. SelfCAD has been created in a way that it has a simplified interface where the tools are well arranged in the interface and figuring them out is easier.

Additionally, the tools of SelfCAD have been greatly reduced to include only the major tools that are mostly useful and most of the tools are reusable too. This reduces confusion and makes learning easier. SelfCAD is also affordable and it only costs $14.99/m or $139.99/ yr.  

Stronger Client-Supplier Relationships

The agreement between the client and the supplier for manufacturing a part has become spontaneous because of instant quote delivery. This price quote happens according to the market standards, which eliminates the doubt of receiving the best offer. The AI systems utilize a model based on supply and demand to quote accurate pricing, a feat that is typically laborious and time-consuming if done manually. 

Pairing automated real-time pricing with an AI-sourcing system helps streamline accepting orders for manufacturers. AI-powered systems also help engineers get the parts designed and sent from CAD to production in merely ten minutes.

Step-by-Step Guide for CAD to CNC Production

Preparing CAD files for CNC production. Image source: ERP

Here are the three crucial steps involved in the transition from CAD to CNC production in detail -

1. Export your design in a CNC-compatible format
2. Prepare a technical drawing
3. Get a quote from an online service

These steps are discussed in detail as follows -

1. Design Exporting to a CNC-Compatible CAD File Format

The first step involves exporting your design to a CNC-compatible CAD file format - STEP and IGES. You can get these CNC-compatible formats fully standardized to be used on several platforms.

Certain manufacturing services also use 3D designs in file formats, including IPT, 3DM, SLDPRT, X_T, and SAT.

While the formats mentioned above are convenient, you must remember that your designs will get converted into the STEP format when the design undergoes the manufacturing process.

It is advisable to export your designs as STEP directly from your CAD software as it lets you examine them before you push the upload button. This way, you can eliminate any room for a conversion error.

2. Technical Drawing Preparation

Technical drawing illustration. Image source: Shutterstock

Modern CNC machining systems are competent enough to read the part's geometry directly from the 3D CAD file using the computer onboard or the G-code output of the CAM software, but the quality of the result still depends on setup details like feeds, speeds, and the milling tools used for the cut. Therefore, you do not require a 2D drawing to manufacture a component using a CNC machining process.

However, it is still advisable to include a technical drawing since the information it contains is not readable in a STEP file. For instance, technical drawing is necessary when your design comprises threads, when you must estimate the tolerances and critical dimensions, or when you must deliver a specific finish to some surfaces.

Regardless of the design comprising these parameters, it is still recommended to have a 2D drawing ready when submitting a CNC order. Several CNC machinists accept technical drawings over 3D CAD files because they simplify the identification of the crucial dimensions, functions, and integral attributes of a part.

Here is a briefing of the steps involved in preparing a technical drawing for CNC fabrication -

1. Precisely define and position the most critical views of the object
2. Add sectional views for concealed geometries
3. Add auxiliary lines such as center marks and center mark patterns
4. Highlight critical dimensions
5. Determine the size and location of all threads with precision 
6. Add tolerance values 

Adding a technical drawing also simplifies the job of the machinists to evaluate the machining operations that occur during the machining process. In case of a dispute, the manufacturers can turn to the technical drawing to corroborate their claims.

3. Go Online to Receive a CNC Machining Quote 

Online manufacturing networks streamline the process of sourcing your CNC production components. You can conveniently and instantly obtain a quote by uploading your 3D files in a supported format, stating your requirements (material, quantity, and processing time), and defining other manufacturing parameters. These online systems are AI-powered and help save time and financial resources while offering a competitive edge. You no longer have to wait for days to receive a quote that might be out of your budget or might not be the best that you could receive.

Final Words

The times when you had to approach a supplier to receive a quote, wait for a couple of days, and provide a plethora of information are history. With the advent of online manufacturing networks, receiving a price quote has become instant.

The article above explains the three steps to prepare your CAD files for CNC machining. All you need to do is export your design to a CNC-compatible CAD file format, prepare a technical drawing to simplify the job and receive a machining quote online, which happens in minimal time.

About the Author:

Peter Jacobs

Peter Jacobs is the Senior Director of Marketing at CNC Masters. He is actively involved in manufacturing processes and regularly contributes his insights for various blogs in CNC machining, 3D printing, rapid tooling, injection molding, metal casting, and manufacturing in general.

---

Enjoy powerful modeling, rendering, and 3D printing tools without the steep learning curve.

Need to learn 3D modeling? Get started with interactive tutorials.