CNC HMC Machining and Machining Centers

Posted on Sep 1, 2020

1
CNC HMC Machining and Machining Centers

HMC machining centers and CNC machining centers cover a wide variety of machine tools, including CNC milling and drilling machines, including vertical machining centers (VMC), horizontal machining centers (HMC), and 4th and 5th axis machine tools. Most include automatic tool changers from 20 to over 500 tools. Workholding solutions often include quick-change tooling or pallets using auto pallet change technology and / or robotic shift technology to ensure actual unattended operation.

CNC machining equipment allows companies to produce complex parts in a user-friendly single-set-up machining process. This design offers significant benefits in terms of productivity - it lowers labor costs, improves part quality and labor time.

Read More: What is a horizontal machining center?

 

Horizontal Machining Centers (HMC)

The HMC version of the CNC turning center includes a horizontal spindle which allows you to speed up the manufacturing process and ensure you don't get interrupted. E.g,the orientation of the HMC allows the chips to fall out naturally, so there's no need to waste time removing them from the table. For maximum efficiency, you can even position the HMC on a pallet while loading work onto a separate pallet.

 

Five-axis machining centers

A popular type of machine is the five-axis machining center, which is most commonly used in the aerospace industry. The five-axis machine has the option of either tilting parts or just tilting. This feature allows the machine to smoothly follow the contoured surface and easily position the tool in different orientations.

 

Vertical Machining Centers (VMC)

VMCs are equipped with vertical action spindles to grip workpieces from above and are most often performed in 2.5 or 3-axis machining operations. Cheaper than HMC consoles, they are especially attractive to small businesses. Over the years, VMCs have become more advanced and include high speed spindles and conversational control programming.

See products : Vertical Machining Centers

 

Why Buy a Horizontal?

The simple answer is productivity and profit. Horizontals can easily do three times the work of a comparable VMC. This statement assumes that the load keeping the computer busy is available. Without a doubt, with the HMC, you can do more in much less time. As production increases, the efficiency of the workshop improves significantly. Since multiple operations can be performed on the HMC in a single setup, less work in progress has to be moved around the shop, increasing productivity.

The HMC console can easily replace three to four risers in many applications. This means that one HMC operator can perform the work of three VMC operators, thus reducing labor costs. While the monthly financial payment for an HMC can be $ 4,800 higher than for VMC, the monthly labor cost for a single HMC can be $ 7,200 lower than that for the same amount of production on VMCs. Also, because HMCs usually have more associated automation, the operator can devote less attention to it, enabling him or her to run another cell, operate other equipment or perform an inspection.

 

Spindle Utilization

Earning money on any CNC machine requires keeping the spindle running so that it produces chips with as little operator intervention as possible. A study by researchers at the university found that "the average VMC utilization, measured by spindle run time, is 25%. HMC utilization is routinely 85 percent. ” A workshop proficient in their VMCs may have 30 to 35 percent utilization, but this is still well below the HMC utilization rate.

During a typical eight-hour shift, the HMC cuts for approximately seven hours, while the VMC cuts for approximately two hours per shift. Five days a week, the HMC gets 35 more hours per week to cut if it works the next shift per day, and even more if it works six days a week. time can exceed 1,200 hours a year. The added cost of the horizontal almost becomes insignificant, provided you have the work to keep the machine fully loaded.

 

Turning parts over

Whenever an operator needs to open a VMC door to load or unload a part, remove chips, perform in-process quality control, or reverse the part, the spindle must stop. If this part requires six sides to be machined, the operator must move the part a total of seven times (load, move five times, unload). When the same part is machined on the HMC, the operator only touches the part three times (load, reposition, unload). Productivity and efficiency have improved. Moreover, thanks to the automatic pallet changer, the operator can handle these operations while the spindle continues to cut the parts on the pallet in the work area. It can also result in improved quality because the HMC requires less operator intervention, which reduces the likelihood of loading errors or other errors.

 

Machine Design Considerations

There has long been a debate as to whether box or linear guides are better. When discussing VMC, it can be argued that there is not enough difference for this choice to matter. The situation is different for the HMC. In the case of HMC, linear guides have proved to be better for higher axis travel speeds on materials such as aluminum as acceleration and deceleration speeds can be higher. As a result, cycle times can be significantly reduced. Some HMC with a linear guide achieve 1G acceleration without sacrificing machine stiffness and without generating excess heat.

However, for some HMC applications, boxed methods may be better. Although HMCs with box guides have slower maximum programmable feed rates, performance is better in operations where high cutting forces can occur. Angle guides are recommended for heavy cuts in hard materials such as titanium, super alloys and tool steel. HMC with box guides provide a perfect finish, even with heavier cuts in hard materials. The spindle head design on the HMC is generally very stiff. This design resists deflection from cutting forces, thus allowing higher chip loads and extending tool life. Some HMCs with larger workspaces have double ball screws on the Y axis which gives proportionally more weight to the Y and X axes.

HMC consoles are built with stiffness in mind, so they are usually much heavier than VMCs the same size. (An average 40 by 20 inch VMC can weigh 16,000 pounds, while an HMC of the same size can weigh over 40,000 pounds.) Due to the greater weight of the HMC, the foundation for this type of machine is more critical. than for VMC. The foundation must meet the HMC constructor's specifications and the machine must be properly positioned and secured. This prevents the machine from "bouncing" during heavy cuts.

 

More information about horizontal machining center

1. The horizontal machining equipment you may need

2. Horizontal Machining Center and Vertical Processing

3. Why Horizontal Machining Center Wins in Certain Cases

 

MTS Exhibition

MTS gathered worldwide horizontal machining centers manufacturers into this online platform. Browse and search for your next supplier with us.

Should you run into any difficaulties, please do not hesitate to contact us.

Quick Link to Suppliers

0Inquiry Item Contact MTS