- Excellent precision and stable performance even during prolonged machining operations
- One-stop solution for machining complex shapes, high-dimensional precision, and improved productivity
In January 2021, I paid a visit to SeJong Precision Machinery Co., Ltd., a company that specializes in the production of dies and molds and fixtures, in order to meet its CEO Lee Jongyoung and hear all about his first-hand experience of DMT’s double column machining center, the DBM 2030 as well as his potential recommendations for improvements. “Because large-sized mold processing uses a lot of materials, a defect can incur big losses in time and cost,” said CEO Lee Jongyoung. “For this reason, it is critical to use a mold processing machine that guarantees outstanding ‘machining precision’ and ‘surface roughness.” He stressed, “We have found the DBM 2030 to be the optimal machine for processing large bumper molds thanks to its automatic exchange head attachment device, larger effective door width, and precision machining of even heavy duty workpieces.
Excellent for Processing Complex Shapes and Ensuring Productivity for Large Workpieces
In general, precision molding involves rough, heavy, and precise machining processes. SeJong Precision, as a company renowned for manufacturing vehicle and motorcycle bumper molds at home and abroad, depends on DMT’s DBM 2030, a multi-purpose 5-axis double column machining center, to process large-sized molds. It takes around twenty-four days to machine motorcycle bumper molds, of which twenty are spent on heavy and precise machining processes. For workpieces with lengthy machining times, not only precision control but also the selection of processes and machine tools that can improve productivity are critical.
Except for rough cutting processes, SeJong Precision uses the DBM 2030 to perform all the heavy and finishing processes that seriously affect its dimensional machining accuracy. “We mainly process KP4M mold steel, but in some cases, we have got to use NAK80 mold steel, too,” said CEO Lee Jongyoung. “Since large molds for bumpers require a long processing time, processing accuracy is all the more important.”
“Most notably, DMT’s DBM 2030 can reduce the mold processing time by more than 3 hours compared to other companies’ machine tools,” said Lee. “The DBM 2030 comes equipped with an automatic attachment changer (AAC) as a standard feature. As such, it is not necessary to move workpieces to a horizontal machining center for side processing, which is one reason why it is significantly more productive than other companies' machine tools that don’t have an AAC. When machining the side of a workpiece in the 90° direction, its machining efficiency is about 30% better than an ordinary 3-axis machining process. Furthermore, the extension head attachment is highly useful for deep shape machining.”
High Dimensional Accuracy Surpassing the Standards
One of the important quality factors in mold processing is 'dimensional precision.' According to the general mold processing standards, small precision molds require a dimensional accuracy of 0.01-0.015㎜, while medium and large molds require a dimensional precision of 0.02-0.03㎜. “The DBM 2030 usually secures a high dimensional accuracy of 0.02㎜ even when processing large molds,” said CEO Lee. “Our customers require an extraordinary level of dimensional accuracy while doing everything they can do to manage their production lines, including shutting off the input of external air in order to minimize thermal displacement. The DBM 2030 fully responds to such needs.” He added that with the DBM 2030, SeJong has been able to continue securing a smooth surface finish when processing mold surfaces.
Powerful Cutting Force and Ease of Operation
The DBM 2030 is structurally designed to minimize the influence of vibration on workpieces even during heavy cutting in the horizontal and vertical directions for 5-axis machining. Equipped with a 55kW high-power ram spindle, it secures a wide range of machining areas from heavy cutting to high-speed and high-precision machining, while the M-shaped cast structure bed helps maintain precision with its excellent vibration damping effects. With the installation of a variety of automatic interchangeable head attachments, the DBM 2030 can process complex shapes, including free angular machining, by a minimum of 1 degree while minimizing the replacement time of the head attachment, ramping up productivity for customers.
According to CEO Lee, “The advantage of the DBM 2030 is particularly prominent in rough cutting procedures. With a torque of 1009 N·m, the DBM 2030 boasts the best specifications in its class, enabling it to provide unrivaled machining power when it comes to rough cutting procedures. Other companies’ machine tools need about 1.3 times deeper cutting to even come close to the performance of the DMB 2030.”
Meanwhile, CEO Lee of SeJong Precision does not hesitate to call the DBM 2030 ‘a machine tool whose operator finds it pretty easy to operate.' Indeed, the DBM 2030 offers ramped up operational convenience thanks to its ergonomic screen configuration, including feed shaft setting and magazine tool setting. Notably, to support the more efficient machining of large workpieces, it comes equipped with a range of excellent features including a 5-axis machining support system, an easy pattern cycle, workpiece load variable control, an AFC function, and a machining monitoring function.
