CNC machining is one of the best examples of how technology has improved the accuracy, efficiency, and cost ratio in industrial product manufacturing. There are a lot of variables to consider when deciding if CNC machining is right for your company, and the cost is typically the first of those. Let’s look at how these variables can all affect the cost, and determine if this manufacturing method is the right choice for you.
MACHINING COSTS
There are a variety of functions that can be performed by CNC machines. Not surprisingly, the more functions that can be performed by one machine, the more efficient it is, but the higher the per hour cost of using that machine. Single-function machines may run around $35 an hour, while 3-axis machines (performing up to 3 functions at a time) will cost closer to $40 an hour. Multi-axis machines, performing more functions simultaneously, may run between $75 and $120 an hour.
To optimize your machining costs, discuss the details of your project with your CNC machining provider and make sure you understand if operator costs are included in the per hour expense, or if that is billed additionally.
LABOR
While CNC machining can save on some labor costs without sacrificing the accuracy of your finished components, there is still labor involved in this process. Operator labor for the actual CNC machining process may be included in the cost of machining. There are additional labor costs to consider for both pre- and post-production.
Initial programming can be one of the most expensive costs as you start up a new project, but this cost may become more reasonable as the number of units produced is increased. This involves the initial breakdown of your project into different machining tasks and determining the order of operation and the kind of CNC matching that would be the most efficient. Keep in mind that once this programming is complete, the resulting programming files can be used for subsequent jobs that have the same specifications, so for long-term, high-volume projects, this cost can be lowered over time.
Once programming is complete, there is an additional cost for set-up of the CNC machine(s) being used. Because this is a function of initial project management, this cost can also be reduced as the number of parts produced is increased. Each time set-up is performed, this cost is incurred, so plan your manufacturing schedules accordingly, and discuss quantity cost differences with your CNC machining partner.
Post-production labor will include any finishing costs, as well as packaging and shipping. As with any manufacturing process, better planning will help you avoid rush or express shipping fees and save you money.
MATERIALS
Obviously, the kind of material you are using for your project will affect your cost. This is not only true for the cost of the material, but also for the cost of machining it. With CNC machining, putting additional planning into the programming phase of your project can help reduce waste by developing CAD files that utilize as much material as possible during machining. Also, the harder the material, the longer it may take for machining, which can increase cost.
Machined materials are typically plastics or metals. Metals include brass, aluminum, or stainless steel. Plastics come in a variety of densities, so consider the cost as a variable against the durability you require in your project. Aluminum is a good material for machining and is an economical choice. Brass and stainless steel have a higher degree of machinability, but will cost more. Discuss the materials you require with your CNC machining partners as part of your initial quote process for better accuracy.
OTHER
Additional costs for tooling may be necessary for two reasons: specific tooling for highly custom fabrication, or frequent replacement of tools due to the hardness of the material being used. When the need for custom tool fabrication arises, discuss this cost with your CNC machining partner. If the creation of a custom piece can become a part of their inventory for other future jobs, you may be able to negotiate a split cost for this piece. However, if your needs require custom tool fabrication that you consider proprietary, you will have to completely bear the cost. Likewise, if your job either uses a harder material or has such a high quantity that tool replacement is necessary during the job. For custom CNC machining, it is vital that you choose a professional machine shop, like Evden Enterprises Inc., that understands your specific needs,
Also, consider the cost of finishing components post-machining (or as part of that process). The more refined your finishing requirements, the higher the cost.
BEST PRACTICES FOR REDUCING COSTS
- Design Wisely – Begin with the design of your product and question every aspect of its production. If special tooling appears to be necessary, is there a better way to optimize the design? The best way to produce a successful product in a competitive market is to balance a simple design with the functionality you require.
- One Part or Two – When critiquing the initial design, consider if one part can be machined to provide multiple functionalities, or if a more complicated part would be more cost-effectively produced if it were accomplished with more than one piece instead.
- Choose the Right Materials – Cost, ease of fabrication, durability, and component performance are all considerations when selecting materials. Consider both the short and long term needs of your products to find the exact right materials to employ.
As with any other industrial production process, CNC machining is the most cost-effective when it is part of an educated, informed manufacturing plan. Work with a CNC machining partner who understands the numerous variables at play and can work through your project to develop a comprehensive, cost-effective CNC machining operation.
