The Cost of Machine Tool

Purchasing the right tools for manufacturing dies and molds can save considerable time and money in the future line, regardless of the upfront cost. There are many factors that affect the real cost of ownership–ranging from the value of financing and resale, operational efficiency and uptime to consumable tooling costs and less secondary operations, which can lead to improved precision. We will discuss how older technology will impede your company’s ability to compete in a global marketplace and how you can make the right investment on moldmaking machinery.

Implementing the Right Strategy

To be successful, you need to have to eliminate as much labor and as many tasks as is possible. With the right tools, whether cutting tools or the machine itself, and/or your software tools are necessary for the speed and accuracy required in today’s market. If you can do all this without supervision, your costs will go down and the higher quality and precision will go up because of it. In the end, you’ll be able to create more efficient products for the end user.

In simple terms, the more old the technology and the more manual work is required, which will cost more money over the long term. If the labor is operating the machine, secondary processes like polishing or hand work the most effective way to cut costs and have the piece delivered more quickly is to eliminate as much manual labor as possible.

The older technology is CNC machines usually older than eight years with slower rpms , and which do not have software installed in the machine to regulate the acceleration and deceleration. However, this doesn’t mean there aren’t modern machines made using this outdated technology. Cutting large, massive cuts at low feed rates was common in the past. However, the slower spindles with the higher horsepower cause low tool life and a low surface finish. Old-style toolholders include ER collets systems as well as endmill holders with screw set-ups. The balance and runout of these holders isn’t ideal for tool life or surface finish.

It’s the time to replace that outdated CNC with an updated or top-of-the-line CNC with features that result in savings in labor costs through the use of toolchangers, tool lasers and proper cutting methods, which results in increased production with the same workforce.

In a typical production-type setting, the cost justification for a per-part piece is essentially black and white: The shop must produce X many parts, so they purchase X equipment. However, in moldmaking environments, it’s much more difficult because the finished product is passed through a variety of areas within the workshop.

If you only look at the machining part, faster is not necessary to be cost-effective. It’s not just the hours spent on the machine. It’s all the other hours or processes like EDM or polishing that need to be reviewed. The actual price of the machine is the amount for the production of an mold insert and that includes how much money is saved reducing secondary operations.

Breaking Down the Cost

For instance that you are currently machining the core or cavity insert on your traditional CNC machine in 50 hours, at $65 an hour ($3,250) and added approximately $300 for consumable tooling costs for two days of polishing (16 hrs X $50/hr) at $800 and one day of spotting costing $400 (8 hrs x $50/hr) your total cost for production would amount to $4750. Investing in newer technology would cut production costs by 25 % through reducing machine time to (30 100 times 100 = $3000) and the consumable cost of tooling to $200 and spending fewer hours polishing (5 hours 50 x $150 = $225) as well as spotting (2 hour x $50/hour = $100).

With the advancement in technology, the total cost would be reduced to $3450.

The tooling that is consumable lasts longer when it is used on higher quality machines. The simple fact that you spend less time changing tools is an cost savings, in addition to the capability to cut an entire part with just one instrument for around 20-30 hours with no blends due to wear on tools.

If EDM is needed, it could be possible to machine these features using modern machines to make even more savings. If companies attempt to cut ribs and other features with older equipment this isn’t cost-effective due to the existing machine quality. The new modern high-speed equipment is capable of cutting very small details that were previously produced using EDM.

With current technology, the finish and accuracy that allow the mold to be sealed and then spotted in a single piece (sealed off to make the part) will happen much quicker. A few years ago, a mold was placed in a spotting press and one to two days were spent hand-grinding and fitting the mold together. When these components have been cut with the required precision, it’s just a few hours instead of days. This is important. Two days off of your delivery time saves your time and money.

Running a machine unattended, for a long period of time, may not result in cost savings if the older technology is running only one tool to finish the job. Some shops say they’re doing light-out with their older machines; but, this is only because their programs were slow to run. They let the machines run, but at a reduced feedrate to be safe and secure. The shops believe they are getting something for free–even when it’s a low-productivity level in comparison to the true, unattended lighting-out facilities being talked about today.

Summary

If you’re looking to remain with the latest machine technology since it offers all these additional options, and you continue to flip these machines over every 3 years or so, you’ll find that the price will go down with time because you’re only paying for the difference between two. Trying to replace five machines at once is an enormous cost to invest in at the same time, and isn’t cost-effective for the majority of small mold manufacturing companies.

About Author: Steven Cheng, the founder of Topworks Plastic Mold, a China injection molding company with the most complete services, from design to production. Topworks provides customers with a one-stop service for Polycarbonate injection molding and ABS injection molding. The company’s professional team has excellent product knowledge of the plastics industry, which enables it to provide customers with quick responses and high-quality service.