When Robert Small wasn't helping guide oil tankers around the globe, woodworking was among his avocations. When he found a very precise router/drill that could finish expansive wood surfaces that can measure yards in diameter, he was able to leave the Merchant Marine and make woodworking his vocation.
This focus on wooden desks, tables, cabinets and other large furnishings provides some differentiation for Quarter Point Woodworking, which Small founded late in 2004. "In the past, a 30- foot radius was quite long. But we've done a lot of templates for people, one of them with a 911-inch radius," says Small, president of the Windham, ME shop.
The enabler for his move into large surfaces with very fine tooling is a router made by Komo Machine Inc., a Sauk Rapids, MN, company known for equipment that produces a smooth edge that doesn't need buffing or sanding. Komo's VR Mach II SHO (Super High Output) vertical router can cut grooves into six-panel doors or other wood panels.
It can also cut boards and drill holes. "This drills holes exactly where they need to be so we can put dados in the correct spot," Small says.
The table size ranges up to 60 by 144 inches. It's the combination of this size and the precision of the machine that lets Quarter Point and other shops create large surfaces. Edges are very smooth and routing lines are accurate, so many wood pieces can be attached to build large furniture that appears seamless to end users.
Though the router cost Small around $160,000, he notes this technology wouldn't have been within the price range of his startup company a few years ago. He has only one other full-time employee, yet Quarter Point competes with a handful of large shops in the Portland area that have equipment for large disks and tables.
With the Komo router, Small doesn't have to compete with the numerous small cabinet makers who can do more conventional projects. "There are a lot of things I can do that most other people can't do," he notes.
Komo uses Bosch Rexroth's FAR rotating nut ball screw drive assemblies and 35 mm ball rail systems. These high-precision profiled rail guides are used on each axis as load support. A set of Bosch Rexroth ball screws and profiled rails on the bottom of the router table move the table.
The gantry, or bridge over the table, features the FAR rotating nut assemblies and ball rail systems. The rotating nut reverses the normal ball screw drive system, using a self-driven ball nut that rotates along a stationary screw to ensure optimum performance. "With larger equipment, we've gone to rotating nuts. This mechanism is much more stable from our perspective," says Jeff Erickson, executive vice president at Komo.
A conventional ball screw works fine with smaller equipment, but when arms get long, ball screws can cause a whipping motion that creates heat and reduces accuracy, Erickson says.
The rotating nut is also faster. "With the rotating nut and our software, we can accelerate and decelerate twice as fast as we could have two years ago," Erickson says.
The router doubles the acceleration rate of the previous Mach II model, with feed rates on the X and Y axes as high as 80,000 mm per minute. The feed rate on the Z axis can reach 22,860 mm per minute.
This speed also addresses tool lifetimes, which is a key factor for operators. "When the blade enters the material, you want to be at say, 300 rpm, but you're starting at 0 rpm; The faster you get up to speed, the less heat is generated from friction," Erickson says.
That brings a big payoff beyond smooth edges. "We've tested against our competitors and we get 50 percent better lifetimes, even when the only difference is our acceleration and deceleration speeds," Erickson says.
Speed is also enhanced by reducing time to switch tooling. Drill and router bits can be carried on the head, and the router will automatically switch to the desired size without manual input.
While performance during cutting is critical for the outcome, Small notes that setup is just as important. Many routers require a user to trace a pattern with a unit that's attached to the router. "If you've got a 30-foot arm out there and the guy is trying to trace a pattern, it's hard to get much precision," Small says.
The Komo tool can be programmed using CAD software, so the router will move along the path that the designer originally created. That's got benefits beyond making lines that fit well. Quarter Point doesn't have to make sure panels are square before starting a job.
"Plywood isn't a square 4 ◊ 8 any more. With traditional cutting equipment, you're going to have trouble if you don't start with a straight edge. That's not a problem for us," Small says.
The ability to reprogram the system quickly also makes it possible to address multiple markets. "We're able to efficiently handle large production orders for contract manufacturing while still remaining cost-effective for short-run piece work," Small says.
The smooth movement can also help save expensive materials. For example, pre-finished plywood with the same type finish as hardwood flooring is difficult for many shops to handle. With many woodworking tools, surfaces often end up scratched, so they have to be sanded or buffed, taking valuable time. "We can cut from the top without leaving any scratches," Small says.
Yet another factor for Quarter Point is that the equipment was easy to set up and operate. He was able to start working shortly after the router arrived. "It's large ó it weighs almost 14,000 pounds and is about 20 feet long ó but a rigging contractor picked it up and installed it in about an hour," Small says. Programming is also simple, he adds.
Maintenance is also minimal. The ball rail runner blocks contain a foam insert that release lubrication over time, virtually eliminating maintenance. The recommended lubrication is every five to 10 million meters of movement.