Johnford CNC Machines
Johnford CNC, which is actually Roundtop Machinery Industries, was established in 1984 in Taiwan. They have been listed on the Taiwan stock exchange since 2001. Roundtop boasts an earthquake-proof office building, strong research and development resources, patented products and a commitment to providing excellence. Since 1992 they have been making vertical CNC lathes, horizontal machining centers, double column machining centers, flat-bed CNC lathes as well as CNC forming machines and screw cutting CNC lathes. According to their catalog, they have 250 employees and two factories in Taiwan.
Johnford CNC Product Support & Service
Roundtop's primary outlet in the United States is Absolute Machine Tools in Lorain, OH, who has partnered with Roundtop to supply Johnford CNC for over 28 years as of 2018. Absolute Machine Tools is the importer and they have a number of distributors around the country who provide service as well.
Johnford CNC Control Systems
Most Johnford CNC include Fanuc controls for reliability and worldwide service. Common features include a 10.4 color LCD display, PCM/CIA slot, USB port, 512KB of memory, a full keyboard and AICC II Contour Control (high-speed machining with 200 blocks look ahead).Also available is an optional data server with high-speed processing up to 1000 block look ahead and 3-axis simultaneous movements up to 60,000 blocks per minute. Another option is the Manual Guide i Software which provides access to material libraries, solid modeling animation, automatic graphical prompt-driven, and a question and answer format to help simplify machine programming.
Some machines come with Siemens controls or Heidenhain controls. Siemens can have LCD screens of 15.1 color, as compared with the smaller 10.4 possible on the Fanuc. Siemens also has ShopMill programming, automatic residual material detection, universal interpolator NURBS and spline interpolation for 3-axis. The Heidenhain has even more sophisticated software options and comes in 2 configurations. One of the configurations is designed for 3-D machining with motion control, 3-D tool compensation, tool center point management, tool radium compensation normal to the tool direction as well as precise interpolation.
The Johnford CNC Machine Models
- Johnford BMC Series: Heaviest Horizontal boring mill in its class has 35 HP and weighs 55,000 lbs. It comes with a heavy duty arm-type ATC which can be separated from the machine for easy maintenance. It holds 60 tools as a standard, with larger tool changes also available. Other standard accessories include a coolant unit, spindle air blast, spindle, and gearbox, cooler, chip conveyor & chip bucket, rigid tapping, leveling bolts and pads and a Fanuc controller.
- Johnford DMC Series: These are double column machining centers (DCM) with high-speed spindles for faster processing efficiency. A high-speed bridge mill that can take the place of large C-frame type mills. Available in a wide range of sizes. The automatic tool changer takes 7 seconds to change tools. Its supported with linear ways to ensure rapid and smooth traverse. Standard machines come with 24 tools, but there are options for 32, 40 and 60 tools.
- Johnford GMC Series: Heavy duty gantry type machining centers these feature a moving bridge on two platforms and a fixed table for unlimited table loads. X-axis travel can be anywhere from 3 to 20 meters. Some machines are equipped with linear motors or preloaded rack and pinion drives to expand the X-travel. There are two types of bridges: the box-in-box bridge and a rugged bridge with offset y-axis ways. The box-in-box bridge is lighter weight and supports headstock with two additional I-beams. All bridges can be equipped with linear scales for y-axis moving precision.
- Johnford GT Series: This is Johnfords large turning center series. The distance between centers can range from 39 to a very long 354. These machines hold 12 tools and have a tailstock quill diameter of 7.9.
- Johnford HMC Series: This horizontal machining center is designed in the symmetrical box-in-box structure. Spindles may be either direct-drive or built-in.
- Johnford HT Series: The HT series are turning centers with a slant bed design for rigidity, chip flow, and accessibility. They are designed for large product runs.
- Johnford JET/DMC Series: High-speed bridge mills that can take the place of large C-frame type mills at a lower price.
- Johnford LC/SCM Series: Large, heavy-duty, high precision flatbed CNC turning centers with a spindle structure supported by precision double row cylindrical roller bearings or high precision taper roller bearings. Various turret configurations are available including front and rear turrets.
- Johnford SL Series: These are Super lathes that come in a wide range of sizes. Optional accessories include C-axis, C+Y-axis, contract tool setting system, parts catchers, programmable hydraulic tailstock, bar feeder interface (or bar feeder), 2 step auto gearbox, rotary tailstock and angle encoder for C-axis.
- Johnford ST Series: These are super turning centers with rugged construction and additional features.
- Johnford VMC/SV Series: C-Frame machines with four oversized box ways to fully support the machines saddle and work table for excellent X-axis accuracy over the full travel range of the machine. Some machines have zero table overhang and a super wide base.
- Johnford VTC Series: This series is a heavy-duty vertical machining series with an automatic pallet changer design for easier loading or unloading of the workpiece. The Jonford VTC also comes with double turrets.