How to Improve CNC Machine Tool Accuracy
How To Improve CNC Machine Accuracy Among the main tasks in machining is ensuring that the new CNC machine tool is accurate and precise. But how will you choose the right tool for your factory, given the bewildering amount of options, configurations, and prices available?
In this informative article, we shall walk you through the step-by-step process needed to optimize your CNC machine's accuracy, repeatability, and tolerances when you purchase a brand new machine tool.
Time for you to Buy New CNC Machine Tool Imagine that you've a brand new manufacturing opportunity or task open to you. You check the engineer's drawing to understand what needs to be achieved, and begin to plan the sequence and process to machine a specific part.
You go during your existing machines, and check on the skill proficiency of your machine operators to see if they could fabricate this part.
Unfortunately, your present CNC machine tools do not have the necessary tolerances to really make the part. They may be of a lower specification or are too old to cater to the new need.Hit on CNC Machine Tool Accuracy Calculation to explore more about our services and sites. Hope you ll like our more services.
When this occurs, you might wish to start purchasing a newer and newer technology.
CNC Machine Tool Suppliers A Tale of CNC Machine Tool Suppliers Now, you will need to weigh the cost of manufacturing each part against the cost of acquiring new CNC machines.
You remember that which you used to pay for your present machines, and set a budget that's as little as possible in order to maximise your profits.
10 years ago, you would've spent USD 80,000-100,000 for your Vertical Machining Centre. OK, you choose to set your budget for a brand new CNC machine to be USD 75,000. Let's see what is available in the market.
As the weeks pass, you contact various machine tool sales people. They attend for your requirements eagerly, offering numerous CNC machines to accommodate your set budget.
Some are lower in price. Others a little higher. Yet others may be much more costly.
All the promises made by these salespersons hinge on the very fact their machines are newer and much better than your present machines. However, none of the vendors consider the facts and tight tolerances of the machined part.
1 day however, a specific salesperson visits you. When you informed him of your specific requirement—while showing him the drawing of your brand-new job—he requires a close look and studies it for a while.
Commenting that this type of machined part may be “difficult to hold”, he then suggested that you'd need machines with good tool holders and cutting tools.
He also highlighted that temperature control is key – in particular, the temperature of your workshop and overall machines. He further adds that the new CNC machine will need linear glass scales, laser measuring tools and an impression probe to measure the machined part and do auto-off-sets.
The salesperson explains that his CNC machine is better than your present units and his competitors. When you ask him for the estimated price, he quotes you – USD 150,000-200,000 – at the mercy of your final specifications.
This really is shockingly higher than your set budget! You could even imagine that the seller was trying to fleece you.
However, in addition you start to take into account what he explained, and realised that it made sense. After all, one other suppliers never discussed these factors. They certainly were only concerned with your axis XYZ, price and the available stocks of these machines, offering additional discounts if needed.
You contact another supplier of a trustworthy brand which is well known in the market.
During his visit he mentioned and repeated the majority of the points of the second sales representative. He further explained that his machine tool uses the Linear Drive system that will be considered the best in the market.
His CNC machine price? A shocking USD 280,000-310,000 – this really is even higher compared to the second vendor even although machine size, spindle speed, and CNC controls are similar.
Now who should you imagine?
Understanding CNC Machining Standards and Accuracy What we've just described happens every day around the world. There are numerous different categories, quality standards, and degrees of CNC machine tools – you need to find out the differences in order to make the right choice.
While machine tool vendors may promise tolerances of +/– 1.5 micron or less, observe that suppliers from different locations or countries may adopt different standards.
For example, there's a positive change between a JIS standard (used mainly by Japanese produced CNC machines) and a VDI standard (used by reputable European manufacturers as well as employed by Hwacheon Machine Tool in South Korea).
These standards have been used for over 30 years to measure and compare the accuracy degrees of machine tools, especially in Asia Pacific.
To understand the differences – and the significance of these differences—it is necessary to master and understand the method CNC machine tool manufacturer use when measuring their CNC machines after final assembly is done.
CNC Machine Tools Mother Machines The Role of “Mother Machines” in CNC Machine Tools All reputable machines tool manufacturer which offer top quality CNC machines make use of a “Mother Machine” to create their own critical parts. They are machines that may achieve the highest tolerances – often within a few microns. The expense of such machines in many cases are very high, and may take the an incredible number of dollars.
If a finish user receives a quotation / offer for a basic standard Vertical Machining Centre at USD 70,000-100,000 (X = 1000 with 10-12,000 rpm spindle), and a guarantee from owner this machine can achieve the same or even “on paper” better accuracy than a costly “Mother Machine”, he needs to be extremely sceptical!
Such claims are too good to be true.
How Drive Systems, Guide Ways and Ball Screws affect Accuracy Think about linear drive systems? Are they really necessary?
Such systems were designed quite a long time ago in order to help machine tools to accomplish faster speeds. Hwacheon Machine Tools had our own experience whenever we designed and built a Horizontal Machining Centre over 18 years ago.
Today, demand for linear drive systems are still present. However, standard CNC machines often omit such systems for their higher costs and greater complexity.
A linear drive system can allow you to achieve good tolerances and accuracy. However, modern machines with top quality Ball Screws and Linear Roller Guides – or Solid Box Guideways (hardened, grinded, and hand scraped to perfection) – can deliver better outcomes in long-term accuracy and stability.
Thus, a CNC machining centre with top quality ball screws in all axis as well as solid hand scraped solid guide ways can achieve the same or similar accuracy to a linear drive version.