doosan rotary table made in china

In Booth S-9092, CNC Indexing & Feeding Technologies (Mason, OH) proudly announces their new partnership with TJR (or Tan Jia) Precision Technology Company, Ltd. (TJR; Taichung City, Taiwan), a well-established supplier of rotary tables to machine tool OEMs such as Okuma, Doosan, DMG Mori, Mazak, and Tongtai. “The new partnership allows us to supply the most technically advanced rotary tables in the industry, with special emphasis on direct drive and 5C collet 4th-axis series units,” explained Steve Smith, the president of CNC Indexing & Feeding Technologies.

The company originated as a rotary table sales and service agent prior to establishing TJR as an OEM in 2009. After much success, they grew to having the largest market share of machine tool accessories in China. Today, TJR is a top OEM with offices all around the world. Their rotary tables are built with high quality features, such as an anti-wearing worm gear and shaft made of high tensile brass for durability. Their encircling braking systems use a large clamping range to prevent displacement during heavy-duty cutting. For tilt rotary tables, TJR offers a 2+1 independent braking system and large diameter radial and axial preloaded bearings for rigid support during 4th- and 5th-axis cutting on both single and dual arm rotary tables. A three-year parts warranty is standard for all new TJR rotary tables.

Doosan recently introduced a two-spindle VMC, its DMP 500/2SP. Company representatives recently spoke with me about the role and application of the machine. Its promise could not be plainer to state: Produce two parts rather than one within a given amount of cycle time and operator attention, and with only a slight increase in footprint compared to a single-spindle machine. While the company says its two-spindle machine has been sold exclusively into high-volume production plants so far, that promise conceivably also makes sense for space-constrained job shops whose business includes higher-volume work.

The two-spindle VMC has just one table and one set of axes. Its work is thus machining in stereo—the machine makes two identical parts at once. A single cycle, programmed just as it would be for a standard VMC, executes the same tool path simultaneously on two workpieces. However, one addition is a single W axis, and Doosan Sales Director Andy McNamara says this added axis is significant. Its inclusion is part of the reason why a two-spindle machine does not have to be challenging to use.

Other aspects of coordinating work between the spindles still require attention, he says. Potential discrepancies in the relative positions of the workpieces in X and Y have to be addressed, and he sees at least two possibilities here. One is to machine the two fixtures for the two parts simultaneously with the tandem spindles. The fixtures will therefore naturally locate accurately to the spindles. However, more commonly, he says, “The high-volume plants interested in this machine tend to use high-end fixture builders who have no issue creating suitable production fixtures for this machine.” One feature of such a fixture might be adjustment screws capable of fine-tuning the X and Y positions of one workpiece relative to the other.

Doosan’s very first user of the two-spindle machine was a high-volume manufacturer fitting this description. Doosan designed the two-spindle DMP machine with this user in mind after the company came to the builder with its problem. The production demand this plant faced for a new set of parts would have required 66 VMCs—too many for the maximum potential space the plant had available. Instead, the manufacturer asked for a machine with two spindles. Doosan’s development of this solution enabled the company to buy only 33 machines instead. (It has since installed more of them for other part numbers.)

William Carr is Doosan’s director of key accounts and engineered applications. He was involved in the project with this large manufacturer and has been involved in other applications of the two-spindle machine. He says there are some important nuances to using a machine such as this effectively—considerations that go beyond coordinating the two parts with two spindles. One is the care needed when using more more than four axes. Rotary tables can be effective with this machine type, but a rotary table with two rotary axes introduces further X-Y variation to a setup that is more complex than that of a typical machining center. For the parts produced on the 33 machines in the initial installation, angled holes are added to the parts using a dual-axis rotary table on a single-spindle VMC.