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Application Tips: Chippers

June 01, 2006 |

The first thing you’ll want to consider when selecting a chipper is the size of the material you’ll be putting through the machine. Once you’ve established the largest diameter tree you want to chip, plan on buying a machine that will handle a little more.

If you’re going to be hauling away trees more than 12 inches in diameter, for instance, you’ll probably be chipping 12-inch trees most of the day, which would be tough on a chipper with a 12-inch limit, says Kevin Covert, sales and marketing manager for Rayco. You could increase the life of your machine by buying the next size up – a 15-inch chipper.

Another decision you’ll need to make is how you want to feed the chipper, says Dan Brandon, marketing manager for Morbark. You can feed a chipper by hand or with a loader, or you can buy a machine equipped with a grapple.

Knowledge of the sites where you’re going to use the chipper is also important. “Will it be easy to gather material and bring it to the unit?” asks Chris Nichols, environmental sales manager for Vermeer. “Does the unit need to be able to go off road and travel to the material?” If you prefer to have a mobile rather than stationary chipper, tracked machines are available. These units may best suit your needs if the majority of your jobsites are in areas where driving a truck and towing the equipment would be difficult, says Colleen Hall, Midwest sales representative, Bandit. Tracked chippers also give you the advantage of being able to work regardless of the weather and resulting ground conditions.

The type and consistency of the end product you desire may be critical to your selection process, and some machines are better than others with different materials. Having dealers demonstrate multiple machines is the best way to find out what end product a chipper will produce in your conditions, Nichols says. (As a starting point, see page 66 for more information about the two basic chipper types – disc style and drum style.)

You’ll also need to decide if you want a chipper with a manual feed wheel or load-sensing hydraulic feed rollers. With manual feed wheels you turn a knob to regulate how fast the chipper pulls in brush, speeding up for light material and slowing down for larger diameter trees. Load-sensing hydraulic feed rollers automatically stop and let the engine catch up if it bogs down. This feature is standard on most large chippers, and is an option on many small units.

Buy a chipper with the largest possible in-feed opening. With a wide in-feed opening, you won’t have to cut as many, or possibly any, branches off trees before you feed them to the chipper. Hand-fed chippers, for example, have in-feed openings that range from 6 to 20 inches wide. If your employees have to delimb trees in order to put them through the chipper, “what you’ll have is a guy taking twice as long to cut as a guy who feeds the whole tree into a 20-inch machine,” Covert says.

At the jobsite
Covert recommends buying at least one tracked chipper and support equipment with tracks so you’ll be able to operate regardless of ground conditions. You need to be able to work even if it’s raining or, if you’re located in the North, the ground is thawing in spring. Make sure your stump grinders are fast enough to stay ahead of site prep contractors, who can get impatient when it’s time to move their equipment to a job and it’s not ready. “Once you fall behind your schedule, it’s very difficult to catch up,” Covert says. “Know your contractors. Know your time tables. And know what equipment you need to complete the job under any circumstances.”