Did you ever wonder how your luxury kitchen or bathroom cabinets got their beautifully carved shapes, even though you know they must be mass-produced? Rather than being carved by hand, it’s much more likely they were made by high speed, automated milling!

When carving intricately patterned cabinets for luxury homes, manufacturers around the world – such as Baygi’s Cabinet and Oakdale Kitchens – rely on the precision woodworking machinery of Markham, Ontario-based Pars Robotics Group Inc. These Computer Numeric Controller (CNC), point-to-point machines can mill cabinets and furniture made of most types of wood including panelwood, medium density fibreboard (MDF), particleboard, and solid wood.

Customized tooling configurations allow versatile, high-precision milling
Customers can order one of three point-to-point machines fitted with different options to suit their output requirements. The multi-axis, PC-controlled machine is fast yet flexible. With a router speed of 1500 to 24,000 revolutions per minute (rpm); an x-axis speed of 80-120 metres per minute (mpm); a rack-and-pinion y-axis speed of 45-80 mpm; and a z-axis speed of 15-20 mpm, the machine takes from five seconds to 10 minutes to mill a piece of wood depending on the complexity of the carving.

The machines are easy to operate. After placing the board on the horizontal bed for cutting (the board is secured to the surface by vacuum suction cups), the operator programs the required wood panel design into the Pars proprietary CAD software. The program is sent to the numeric controller, and to the 3 to 6 servo drives for correct tooling positioning. The PC-based PLC card activates the tools (vertical/horizontal drills, router, saw, and profile sander) which cut the wood to the required shape. When finished, the tool head returns to its “park” position, and the milled wood is released from the vacuum for operator pickup.

After placing the board on the horizontal machine surface for cutting (the board is secured to the surface by vacuum suction cups), the operator programs the required wood panel design in the Pars proprietary CAD software.

To facilitate high-precision milling, the Pars Machining Centre tooling includes 15 vertical spindles and eight horizontal spindles; a router with a quick-change chuck; and a saw with up to 90 degree adjustments in both directions. And, because the machine can interpolate in three axes, it can cut spiral shapes in the wood.

The machine achieves smooth, clean carving lines because its routers operate at high speeds. Key to the router functioning reliably at high speeds is the motor’s ability to quickly ramp up from 0 to 24,000 rpms. “We achieve the most effective, reliable motor control for high speed routing applications with a Schneider Electric Telemecanique Altivar 28 variable speed drive”, says Cameron Raadi, Control System Engineer, Pars Robotics Group Inc.

Because Pars Machining Centre users carve a wide variety of patterns in many different types of wood, they require highly customized, easy-to-change tooling. “Customized tooling is a key requirement for users who fabricate specialty furniture with unique shapes”, says Raadi. Users requiring multiple tooling (router, spindle, saw and sander) configurations for different milling applications can have an automatic tool changer installed to allow fast changeovers. And the machines can have up to five axes to create sculptured wood. “A 5-axis machine is ideally suited for carving intricate shapes because it can cut into the flat surface of the wood at any angle (3 axes can only cut at a 90 degree angle)”, explains Raadi.

Real-time simulation facilitates CAD software programming
The CAD software minimizes training and setup time because pre-programmed macros encapsulate most of the woodworking configurations. This allows the operator to select a complete routine by simply clicking on the correct icon.

Key to minimizing wastage and downtime is the software’s real-time simulation program. This feature enables the user to remotely write and execute a routine in simulation mode to check for programming errors before running the routine “live” with a piece of wood on the machine. Errors are easily identified by the software’s debug function, which allows step by step simulation of the program. And, to minimize cycle time, the software optimizes each routine.

Pars engineers can, from the Markham office, remotely perform on-line diagnostics via modem or Internet on their machines located anywhere in the world. “This minimizes downtime and eliminates the cost of on-site visits to the customer”, says Raadi.

Machine safety features reduce wastage while protecting operators
If the operator stops the machine during horizontal drilling, a “reverse” PLC program automatically removes the drill bit from the wood when the machine is started up again, and resumes the routine. This unique feature prevents tool and board wastage (due to breakage) and possible operator injury.

Telemecanique XS inductive proximity sensors enable the tooling axes to hone in on their zero starting point when the machine is turned on, and they stop the machine if any of the axes continues beyond its prescribed limit. Telemecanique XUL photoelectric sensors, acting as gate guards, automatically pause the axis movement if an object or a person breaks their beam.

Rugged machines yield artisan quality woodcarving at high speed
In addition to the customized tooling and user-friendly CAD software, customers specify Pars Machining Centres because they are rugged, reliable, and yield artisan-quality carving at high speeds. “High speed, precision milling is key to producing large volumes of panels with complex carving patterns that must adhere to very high (+ or - .002 mm) quality standards”, says Raadi.

Users also appreciate the fact that Pars CNCs are easy to maintain, technical support is easily accessible, and components and service are available worldwide.

To meet these customer requirements, Pars specifies Schneider Electric Telemecanique variable speed drives, sensors, beacons, contactors, relays and pushbuttons for their machine control systems. “These Schneider Electric components are of very high quality. They’re rugged and reliable”, says Raadi. “We are also very impressed with the Telemecanique Altivar 28 variable speed drives’ advanced technology.” In addition to being easy to program, its “At Speed” option signal for the routers can be fed to the PLC, which launches the next phase of the routine in real-time. Pars also appreciates the worldwide availability of Schneider Electric’s components and their application, technical support and field service expertise.

Concludes Raadi: “Customers buy our machines because they increase productivity, quality and uptime”.

Such high-tech artistry – wood you believe it?

For more information, contact Dan Pasianotto at pasianod@squared.com or (905) 678-7000.