Starting out as a welding shop special, the Roto-Lim has evolved as an economic delimbing alternative for contractors.

By John Dietz
Copyright 1997. Contact publisher for permission to use.

As Manitoba contractor Herb Bresky is demonstrating, there is more than one way to get into mechanical delimbing without mortgaging the farm to the local equipment dealer. When Bresky got into the logging business 35 years ago, a chain saw in the hands of an efficient bucker was the method of choice, along with a pass or two over the logs with the dozer blade. Manual bucking and delimbing is still around, of course, but for the most part the landing bucker has given way to high-production mechanical delimbers.

But for Bresky, who utilizes both mechanical feller-bunchers and grapple skidders, paying $300,000 or so for a single-use delimber was a bit much. Through the 1980s, he stuck with chainsaws.

Each winter, however, the delimbing part of the show became an operating bottleneck. The small company logs about 15,000 cords a year in Manitoba's Duck Mountain Provincial Forest. Bresky began wondering how he might expedite the process without putting his firm in a financial bog in the process. He had in mind initially what could best be described as a big, straight-toothed rake.

"But the problem is that a rake just won't work. You've got to have something that will fit both big and small trees."

One Sunday afternoon in March, about eight years ago, Bresky had some spare time and was doing a little monkey-wrenching on his feller-buncher. He says, "I started thinking that some solid teeth on a shaft that could rotate might just do the job."

That spring, when he came out of the spruce and poplar forest, he went to a local welding shop with his idea and some drawings. The basic device that emerged had three 15'' flat paddles on the end of a short steel tube. Bresky mounted four of these free-turning devices arranged side by side in a steel frame on the front of his dozer, in place of the blade, and headed out to give it a try.

"It worked 10 times better than I thought," he says. "The second day I used it, I phoned in a report, sent a picture away and put a patent-pending on it." He called it the Roto-Lim. The device utilizes paddles nearly long enough to touch the adjacent shaft. To prevent paddles on one shaft from hitting paddles on another, they are welded into an off-set or alternating pattern. The number of paddles employed and their placement are the key elements to the design.

He found that with his first three-paddle prototype, the paddles wouldn't enclose the trunks tightly enough to take limbs off at the bottom. He soon found by experimenting that a four-paddle design worked best. "Two doesn't work, three paddles isn't enough, four is just perfect and five paddles is too many."

When the frame lowers onto the stems, the paddles flip around to the bottom and actually hold the trees in place. While the grapple holds the trees at one end, the dozer or skidder is driven forward from the opposite end. Roto-Lim paddles snap off all the branches along the way. It takes two or three passes to get all the branches on all the trees being held, he says.

With eight seasons behind him using the Roto-Lim, Bresky says, "It cannot be simpler. We've never had a plug-up, never had a tooth break off. No maintenance whatsoever, except for greasing the shafts once a day. And anybody can operate it."

Bresky has modified the frame slightly from the early device. Between each shaft, the frame now has a concave, flat surface that snugs against a tree trunk. "That way we get much more of the paddle scraping the tree. And we've got a cutting edge on that, too, so it cuts as it slides along the tree."

The whole device, held to the front of a dozer or skidder by four pins, is easy to attach or remove. "You can drop it off if you want to go skidding, and put it back on quickly if you need it. It doesn't tie up a machine."

For a small investment (about $7,000) in a simple machine, Bresky says he's been getting a big return. Using the Roto-Lim, Bresky's crew has limbed as much as 300 cords a day. "We've got three grapple skidders, and one machine will limb for all three."

In warm weather, when branches start to bend instead of snapping off, he admits it may do only "90 to 95 per cent" of the limbs. Still, it's faster than a chainsaw and it never wears out. "We don't have the bottlenecks any more. This speeded my operation up right off the bat, and we don't have the problems we had before, during the winter."

Cost per cord is another way to look at his simple machine. Bresky estimates de-limbing costs at $2.50 to $3.00 a cord for the Roto-Lim mounted on a small skidder. That's a price-tag that a small operator can afford, he says.

Commercial manufacturing of the Roto-Lim began in 1991. Since then, Bresky says, more than 300 have been made. They're sold through forestry equipment dealers in Canada and the United States.