A wood chipper vs brush chipper comparison starts with a naming problem: “wood chipper” is the general name for any machine that cuts branches into chips, and “brush chipper” is the trade name for the trailer-mounted and tractor-driven machines built for tree work. Every brush chipper is a wood chipper, but the plug-in or small gas unit in a home garage is not a brush chipper. I prune a 3.7-acre apricot and plum orchard every winter, so I know which pile belongs to which machine. Below I compare capacity, feed, power and safety, then say which one fits a home property.
The Short Answer on Wood Chipper vs Brush Chipper
Use “wood chipper” for the whole family and “brush chipper” for one branch of it. Toro prints the name “Brush Chipper” on the manual of its 22604 model, a 25 HP Kohler machine on a trailer with a 6 in. hopper opening. Vermeer uses the same name for trade machines sized for tree crews. A home unit is a chipper shredder with a hopper or a chute, built for twigs and small branches from your own trees. My guide to what a wood chipper is sorts the types, jobs and limits.
| Point | Home wood chipper | Brush chipper (trade class) |
|---|---|---|
| Where the name is used | Everyday word for any chipper | Trade and manual name for trailer or tractor machines that chip limbs and brush |
| Opening, in the makers’ words | Sun Joe CJ603E: cutting diameter 1.73 in.; Earthquake 33968: chipping approx. 3 in. | Toro 22604: hopper opening 6 in. maximum; Vermeer sizes trade models from 9 to 12 in. up to 15 to 19 in. |
| Power | 15 A plug-in, or a gas engine (Champion: 224 or 338 cc) | Gas engine (Toro: 25 HP Kohler) or tractor PTO |
| Weight, with the manual’s basis | Sun Joe CJ603E 38.6 lb (“Weight”); Earthquake 33968 121 lb (net) | Toro 22604 1,056 lb (“Weight”) |
| Moving it | Carried or wheeled by hand | Towed or mounted on a tractor hitch, at the speed the manual prints |
For a pruning pile at home, a home wood chipper does the job and a brush chipper is more machine than the pile needs. I recommend the larger class only for property owners with a lot of thick wood and the right setup: a PTO machine needs a compatible tractor, and an engine-powered towable machine needs the towing vehicle and setup its own manual specifies. My comparison of a 6-inch and 8-inch wood chipper shows what each size handles.
What a Brush Chipper Is
A brush chipper is a self-feeding mobile chipper made for limbs, brush and small tree limbs. The machine takes its power from its own engine or a tractor, and it is towed or hitched to a tractor.
Where the Name Comes From
According to NIOSH, a self-feeding mobile wood chipper has three parts: a feed mechanism, knives on a rotating chipper disc or drum, and a power plant. The disc or drum turns between 1,000 and 2,000 rpm. The Toro brush chipper, the 22604, chips “branches, vines, leaves, and small tree limbs up to 6 in.” and is not meant for rocks, wire or metal. I explain how a wood chipper works, from rotor and knives to the feed, in a separate guide.
Trade sizes run past that. According to Vermeer, a commercial brush chipper of 9 to 12 inches suits trimming work, while takedowns and land clearing call for 15 to 19 inches. Vermeer’s own rule is to buy a machine that handles at least 80 to 90 percent of the wood you plan to chip, because a chipper that is too small strains and wears fast. The same rule works at home: size the machine to the wood you really cut. For smaller sizes, my comparison of a 3-inch and 4-inch wood chipper shows what each takes.
Disc or Drum
Both cutting designs appear in this class. According to Vermeer, a drum suits wide openings and large wood, and a disc is the more operator-friendly design, with infeed roller controls. The drum versus disc choice is a crew’s buying decision, not a pruning pile decision. My drum vs disc wood chipper guide shows how each one cuts, feeds and wears.
What Homeowners Call a Wood Chipper
Home machines fall into two groups, and neither is a brush chipper. One is the plug-in hopper unit, the other the gas chipper shredder with an angled chute for branches and a top hopper for leaves. My comparison of a wood chipper and leaf mulcher shows which one handles a leaf pile.
Electric Hopper Units
The Sun Joe CJ603E is a good example of the plug-in class. Its manual prints a 15 A motor on 120 V, a cutting diameter of 1.73 in., a paddle to push material in, and a forward and reverse switch. The WEN 41130 prints 1-3/4 in. as its maximum cutting diameter. An electric brush chipper for home use is really a hopper unit, and the manuals of these plug-in machines stay near 1.5 to 1.75 inches of branch. I set these two plug-in models against each other in my CJ603E and WEN 41130 comparison.
On my place the house and sheds sit about 100 to 150 feet from the nearest row. That distance makes a plug-in unit a yard-and-shed machine for me, and the cord decides where it works. I route the cord away from the hopper and my feet, because a cord under the feed path is a mistake I corrected early. I cover one such plug-in chipper shredder in my WEN chipper review.
Gas Chipper Shredders
A gas chipper shredder has two inlets on one rotor. The Earthquake 33968 prints chipping capacity of “approx. 3 in.” for its chipper cone and a shredding capacity of 1/2 in. by 18 in. long for the hopper; for engine data the manual says “see engine manual”. Champion prints 3 in. for the chipper chute and 1/2 in. for the shredder hopper on its 224 cc and 338 cc models. Earthquake describes the feed as self-feeding: the manual tells you to let the unit draw the sticks in. I set two of those gas units side by side in my guide to Earthquake and Champion chipper shredders.
Two openings, two limits
The chute and the shredder hopper of one gas unit take very different material. Champion and Earthquake both print 1/2 in. for the hopper, so a branch that fits the chute can still be far too thick for the hopper.
Capacity and Which Branch Each Machine Takes
Capacity is the first thing to check, and the makers print it in different words. Read the opening named in the manual and the limit beside it, and never carry a number from one opening to another.
| Machine | Opening | Limit in the maker’s words |
|---|---|---|
| Sun Joe CJ603E (electric) | Hopper | Cutting diameter 1.73 in. |
| WEN 41130 (electric) | Hopper | Maximum cutting diameter 1-3/4 in. |
| Earthquake 33968 (gas) | Chipper cone / shredder hopper | Chipping approx. 3 in. / shredding 1/2 in. by 18 in. long |
| Champion 200905 (gas) | Chipper chute / shredder hopper | Max diameter 3 in. / 1/2 in. |
| Toro 22604 (brush chipper) | Hopper opening | 6 in. maximum |
| Woodland Mills TF46 PRO (PTO) | Infeed | Brush with trunks exceeding 4 in. is never used |
A Worked Example With Three Branches
Take three branches from a pruning pile, at 1 inch, 2.5 inches and 5 inches thick. The 1 inch branch fits the CJ603E and either gas chute. I cover the CJ603E in my Sun Joe CJ603E chipper review.
The 2.5 inch branch fits the Earthquake and Champion chutes at 3 in. but is too thick for the CJ603E at 1.73 in. The 5 inch limb is past every home machine in the table. It goes to firewood, a larger rental machine with its own manual, or a professional. My log splitter and wood chipper comparison shows where thick wood belongs instead.
Champion warns never to insert pieces larger than 3 in. in its chipper chute.
After dormant pruning, which takes 20 to 25 percent of the canopy, the pile along my rows is mostly twigs and thin branches. I sort the thick limbs for firewood and feed only the small wood, because forcing a thick limb into a home machine is the quickest way to stall it. My comparison of a wood chipper and log splitter covers the firewood side of that pile.
How the Feed System and Control Differ
The biggest difference between the two classes is how material reaches the knives. A hopper unit lets you place a branch and the knives take it. A trade machine with powered feed rollers pulls the limb in on its own and can be stopped or reversed only from its control. My comparison of gravity and hydraulic feed chippers covers how material reaches the knives.
Hopper and Chute Feeding
On the Sun Joe and WEN hopper units a paddle pushes short material in, so your hand never goes into the hopper. On gas units the branch goes into the chute butt end first. A forked twig has hung up at a hopper mouth on me, and I let go and treated it as a jam, with the full shutdown described further down.
Feed Rollers and Control Bars
Woodland Mills describes hydraulic feed on its PTO chippers with a control arm that has forward, neutral and reverse. OSHA describes the same idea as a feed control bar: pushing it to the center position stops the rollers, and pushing it toward the discharge spout reverses them. A roller pulls a limb in faster than a hand can let go.
That is why the injury literature on work chippers centers on the feed mechanism. A review of cases found deaths from being caught in the feed and from being struck, and the authors note that current feed wheel controls do not let a caught worker rescue himself (1). The CDC reported that operators were pulled into the knives through the feed chute or struck by the hood opened while the knives still turned (2).
Home machines hurt people too. A plastic surgery report described severe hand injuries that operators inflicted on themselves with yard shredder and chipper machines, with some needing complex reconstruction (3). A case series of tree care workers lists being caught in a woodchipper among the main fatal incident types (4). The cases come from work and clinical settings, so I read them as a reason for habits, not as a number for a homeowner.
Hands out, feet out
Never put your hands, feet or any part of your body into the hopper, the chute or the discharge while the machine is running or the rotor is still turning, and never reach past the rubber flap or the mouth of the chute. Push short pieces in only with the paddle or push tool your manual supplies, or with the next branch or a small stick as your manual describes, never with your hand or foot. Stand to the side of the hopper or chute, never directly in front of it, and feed branches butt end first. Hold the branch near its outer end with an open hand, never wrap your fingers tightly around it, and let it go as soon as the machine draws it in; never follow a branch into the chute. Feed only the material and the branch size your manual allows, into the opening it names.
The agency rules for crews do not transfer to a home hopper unit. Champion and Woodland Mills ask for one operator at a time, and a helper never touches the controls and stays outside the work area. The second-worker and lockout rules in the work-chipper literature are for large crew machines, so I follow the exact manual of the machine in front of me.
Power, Weight and Towing
Power decides where a chipper can work, and weight decides how you move it. A plug-in unit needs an outlet, a gas unit needs fuel and clear air, and a tractor machine needs a tractor. My guide to electric and gas wood chippers shows what each can chip.
Plug-In and Gas Engines
The CJ603E weighs 38.6 lb by its manual’s technical data and the Earthquake 33968 weighs 121 lb net, so the second needs help to lift. Before you move or lift any chipper, put it in its safe state. On an electric unit, switch it off, wait until the blades have stopped completely and unplug it by the plug, not the cord. On a gas unit, turn the engine off, wait until the rotor and every moving part have stopped completely, let the engine and muffler cool, and pull the spark plug wire off and secure it away from the plug.
Earthquake and Champion say to use at least two people to lift a gas unit and to grip it by the front leg and hopper handle. Never move, tilt or carry a running machine, never carry a unit by its cord or its fuel tank, and store it dry and out of children’s reach.
Gas and electric basics
Refuel a gas chipper outdoors with the engine off and cooled for at least two minutes, as the Champion and MTD manuals say, with no smoking, flames or sparks nearby; open the cap slowly, wipe spills and never start the engine where fuel spilled. Never run a gas chipper indoors or in a garage or shed, even with the doors open: the exhaust contains carbon monoxide, which you cannot see or smell. Before you start, with the engine off and cool, clear chips and dry leaves from the engine and muffler; if debris builds up during work, complete the full gas maintenance shutdown, spark plug wire off included, before you clean it away, and keep every cooling and combustible-material clearance your manual gives (Champion: 3 feet around the machine for cooling and 5 feet from combustible materials and dry vegetation; SuperHandy GUO148: 2 m, 6.5 ft, from flammable materials). Pull the starter cord slowly until you feel resistance, then pull rapidly, and never start the engine with material in the hopper or chute.
Tractor PTO Machines
A PTO brush chipper takes its power from a tractor through a shaft. According to Woodland Mills, its TF46 PRO needs a tractor with at least 15 PTO horsepower, weighs 620 lb by its manual’s product weight and runs at 540 PTO rpm. Read the driveline warnings in the PTO manual first, because the shaft can entangle clothing and cause serious injury or death. My guide to PTO and gas wood chippers compares the two power sources.
PTO rules
Keep the tractor’s master shield and the driveline shields in place, connect or adjust the PTO shaft only with the tractor engine off, the key out and the driveline stopped, engage the PTO at idle, and never run a 540 RPM chipper above 540 RPM. Follow the stopping order in full before you touch the chipper: throttle to idle, disengage the PTO, turn the tractor engine off, remove the key and set the parking brake, and wait until all noise and vibration have stopped.
Towing a Trailer Chipper
A towable brush chipper rides on its own wheels behind a vehicle. The manuals disagree on the speed limit: one prints 15 mph, another 25 mph and Toro prints 45 mph, so none of those numbers is a general rule. My guide to towable and walk-behind wood chippers shows which one fits a property.
Towing
Tow the chipper only as its manual describes: a hitch that matches the coupler, safety chains attached as the manual specifies, with slack for turning, the jack stand raised, lights and tires checked, the engine off and the fuel valve closed, no riders and no cargo on the machine, and never faster than the speed your manual prints. Set it up for work exactly as your manual describes (Toro, for example, requires unhitching it from the tow vehicle first).
Brush Chipper Safety for Either Machine
A chipper has a fast-spinning rotor, flywheel, knives or hammers behind the inlet. A hand, sleeve, glove or drawstring that reaches the inlet can be drawn in faster than anyone can let go, and the same machine throws chips, stones and metal out of the inlet and the discharge. The rotor keeps turning after the switch or engine is turned off.
Before You Start
Gear and site come first. Wear safety glasses or goggles with side shields marked ANSI Z87.1, and a full face shield where your manual asks for one; hearing protection; gloves only as your manual directs, and where it asks for gloves, snug ones without loose cuffs or drawstrings; long pants and sturdy non-slip boots; and respiratory protection as your manual requires (WEN: NIOSH-approved dust masks or other respiratory protection during operation and cleaning; Woodland Mills: a dust mask in dusty conditions). Never wear loose clothing, scarves, jewelry or dangling drawstrings, and tie up long hair: anything that catches on a branch can be pulled toward the inlet.
Site and weather
Set the machine on firm, level earth or grass, never on a slope, on pavement, concrete or gravel, or close to a wall or building, where chips and stones ricochet. Clear the area of stones, wire, rope and other loose objects first, and work in daylight. Never work on wet or slippery footing, where you could slip toward the inlet, never run an electric chipper in rain or in damp or wet conditions, and stop any chipper and seek shelter if you hear thunder or see lightning.
Thrown objects and bystanders
The machine can throw chips, stones and metal out of the hopper and the discharge. Keep children, pets and other people out of the work area, at least the distance your manual prints (the Champion, MTD and Yardmax manuals ask for 75 feet), and stop the machine at once if anyone comes closer. No distance makes a work area safe on its own: keep watching it. Never point the discharge at people, animals, windows, cars or buildings, and never look into the hopper or chute while the machine runs.
What not to feed
Feed only clean wood and plant material that your manual allows, into the opening it names and within that opening’s limit. Never put in stones, soil, metal, nails, wire, glass, plastic, cans or bottles, and remove soil and stones from roots first. Leave out pressure-treated wood, painted wood and lumber unless your manual allows them; several manuals ban treated and kiln-dried lumber outright.
Before every start, check that the guards, flaps, hoppers, discharge chute and any collection bag your manual requires are fitted and secured (Earthquake forbids running without its debris bag), and that knives, fasteners, the cord or the fuel system are undamaged. If the machine starts to vibrate abnormally, stop it at once, complete the full maintenance shutdown and have the cause fixed before you restart. I run through that check every time, and I put ear protection on first, because the family is closer to the noise than any neighbour.
For an electric unit, use an outdoor-rated extension cord of the gauge your manual gives for its length (the Sun Joe manual allows no cord longer than 100 feet), plug into GFCI-protected power, keep the cord away from the hopper, the discharge and your feet, and never touch the machine or the plug with wet hands or while standing in water. Never carry the chipper by its cord or yank the cord to unplug it.
When Something Jams
If a branch will not feed, kicks back or cannot be controlled, stop feeding and let go: never chase it into the chute or try to hold it back. Remove trapped material only after the full maintenance shutdown for your power type, with every extra step your manual adds. Keep the discharge area clear: chips that build up there can make new material kick back toward you.
Clearing a jam, by power type
Never use your hand, foot or any body part to unclog the machine, even after it is shut down. On an electric hopper chipper, switch it off, unplug it from the outlet by the plug, and wait until the blades have stopped completely; never open or clear any electric machine until it is unplugged and all motion has stopped. On a gas chipper, follow your manual’s own shutdown sequence and every wait it prints: the engine off, the rotor and every moving part stopped completely, the engine and muffler cooled, the key removed where fitted, and every spark plug wire pulled off and secured away from its plug, or grounded against the engine where your manual says so. On a PTO chipper, throttle to idle, disengage the PTO, turn the tractor engine off, remove the key and set the parking brake, wait until all noise and vibration have stopped, and disconnect the PTO shaft. Then follow your manual’s own clearing steps: open only the hopper or panel it names, remove the material only with the tool it names, and refit every guard and any required bag before you restart.
The Champion manual adds steps of its own for a clog on its gas units, and they come on top of the gas order above. For a slight clog, rock the unit by the handle. If that fails, close the fuel valve and let the engine run until fuel starvation stops it, switch the engine off, wait until the rotor and every moving part have stopped completely and the engine and muffler have cooled, then disconnect the spark plug wire and secure it away from the plug.
Next, remove the material on top of the shredder hopper without putting a hand inside, using only a branch under 1/2 in., and refit every guard and any bag before you restart. For a serious clog, Champion tells you to turn the engine off, disconnect the spark plug wire, let the unit cool and drain the fuel before you open the access panel. Toro asks you to wait five minutes with the engine off so the flywheel and all moving parts stop and cool, then remove the key and disconnect every spark plug wire.
Hearing and Dust
The Sun Joe CJ603E manual rates the unit at 94 dB, and NIOSH recommends limiting noise to 85 dBA averaged over an eight-hour workday (5). Wear hearing protection on any chipper. A study of chipper operators in Italy found wood dust exposure was about three times higher for operators working in the open than for those in an enclosed cab (6), which is a reason to follow your manual’s respiratory advice.
Break rule
Feeding branches is heavy, repetitive work: take breaks, and stop when you are tired or your attention slips. A sore back or numb hands mean stop and rest.
Which One Fits a Home Property
Match the machine to the wood and to the power you have on site. Start with the widest branch you cut and the distance from the outlet to the pile. My ranking of the top small wood chippers covers five light electric and gas picks.
Twigs and Prunings
For twigs, thin branches and leaves, a plug-in hopper unit or a 3 in. gas chipper shredder is the right class. I recommend the electric unit when the pile sits near an outlet, and the gas unit when the work moves along the rows. In both cases the manual’s limit is the limit. My guide to wood chipper and chipper shredder openings explains the two names.
Limbs Beyond a Home Machine
A limb thicker than the stated capacity of the machine in front of you is a rental job or a job for a professional. Hire a professional for trees to cut down, limbs thicker than the machine’s capacity and large brush piles. A rented trade machine comes with its own manual, and its feed rollers and control bar ask for more care than a hopper, so read that manual before the first cut.
Trees and Power Lines
Cutting down a tree or climbing one is not a chipper job. Anything near a power line goes to the utility and its qualified line-clearance crews.
Choosing Between the Two Machines
Remember three things. A brush chipper is a wood chipper built for trade work, a home unit is a wood chipper sized for your own trees, and the manual’s capacity decides what goes in. My list of the top wood chipper picks covers nine electric and gas models.
My tip from the orchard is to stack thin prunings and thick limbs in separate piles before you start, so the right wood meets the right machine. For the next step, read the manual of the exact machine and the safety section above, then check the widest limb on your pile. In the end, the wood chipper vs brush chipper decision comes down to the widest limb you cut and the power you have on site. My wood chipper vs chainsaw comparison shows which tool takes which branch job.
Frequently Asked Questions
What is a brush chipper?
A brush chipper is a self-feeding wood chipper, usually towed or hitched to a tractor, that is built for tree work and takes limbs, vines and brush. Toro describes its 22604 brush chipper as chipping branches, vines, leaves and small tree limbs up to 6 in. in diameter. A home chipper shredder with a hopper is a smaller machine.
How big is a wood chipper?
A wood chipper is sized by the widest branch it takes, which runs from under 2 in. on plug-in home units to 8 in. on large tractor models in the makers’ manuals. The CJ603E weighs 38.6 lb and the Toro 22604 weighs 1,056 lb, so weight varies as widely as capacity. Always read the opening the maker names.
Is it better to use mulch or wood chips?
Wood chips are a kind of mulch, so the choice is between chips and another material, and Washington State University Extension calls wood chips one of the best mulch choices for trees and shrubs. Depth advice differs: Illinois Extension gives 2 to 4 in., Georgia 2 to 3 in. and Washington State 4 to 6 in. Keep mulch off the trunk.
Is a brush chipper the same as a wood chipper?
A brush chipper is a wood chipper, but a wood chipper is not always a brush chipper. The brush chipper name goes to the larger trailer-mounted or tractor-driven machines made for tree work, while the plug-in and small gas units at home are chipper shredders.
What is a commercial brush chipper?
A commercial brush chipper is a trade-grade wood chipper sized to the work of tree crews and land clearing. According to Vermeer, 9 to 12 in. capacity suits trimming work and 15 to 19 in. suits takedowns. A home owner with limbs beyond a home machine rents a larger one with its own manual or hires a professional.
References
- Zhu J, Gelberg K. Occupational fatal injuries associated with mobile hand-fed wood chippers. Am J Ind Med. 2018;61(12):978-985.
- Centers for Disease Control and Prevention. Fatal and nonfatal occupational injuries involving wood chippers–United States, 1992-2002. MMWR Morb Mortal Wkly Rep. 2004;53(48):1130-1131.
- Hallock GG. Mutilating shredder/chipper hand injuries. Ann Plast Surg. 1994;33(1):6-8.
- Kearney GD, Imai S, Doub A, Langley R. Fatal incidents among tree care workers in the United States: A case series approach. J Occup Environ Hyg. 2024;21(9):629-637.
- National Institute for Occupational Safety and Health. Noise-Induced Hearing Loss. Noise and Hearing Loss. Centers for Disease Control and Prevention; 2024.
- Magagnotti N, Nannicini C, Sciarra G, Spinelli R, Volpi D. Determining the Exposure of Chipper Operators to Inhalable Wood Dust. Ann Occup Hyg. 2013;57(6):784-792.
Safety Note: Only an adult who has read the manual and understands the controls should use a wood chipper or shredder, never a child or anyone tired or impaired. The rotor, knives, hammers or cutting line behind the inlet can draw in a hand, a sleeve or a glove faster than you can let go, and they keep turning after you switch the machine off. Never put your hands, feet or any part of your body into the hopper, the chute or the discharge while the machine runs or the rotor still turns, never reach past the rubber flap or the mouth of the chute, and push short pieces in only with the paddle or push tool your manual supplies, or with the next branch or a small stick as your manual describes. Stand to the side of the hopper, never in front of it, feed branches butt end first with an open hand near the outer end, and let go as soon as the machine draws the branch in; if a branch kicks back or will not feed, stop feeding and let go, never chase it into the chute. Feed only the clean material your manual allows, into the opening it names and within that opening’s limit (a chipper chute and a shredder hopper have different limits, and a leaf mulcher takes no branches, sticks or brush), and never stones, soil, metal, nails, wire, glass or plastic. The machine can throw chips, stones and metal: keep children, pets and other people out of the work area, at least the distance your manual prints (the Champion, MTD and Yardmax manuals ask for 75 feet), stop at once if anyone comes closer, and never point the discharge at people, animals, windows, cars or buildings. Set the machine on firm, level earth or grass, never on a slope, on pavement, concrete or gravel, or close to a wall, work in daylight, never work on wet or slippery footing where you could slip toward the inlet, never run an electric chipper in rain or in damp or wet conditions, and stop and seek shelter for thunder or lightning. Wear safety glasses or goggles with side shields marked ANSI Z87.1, a face shield where your manual asks for one, hearing protection, gloves only as your manual directs (snug ones without loose cuffs or drawstrings where it asks for them), long pants and sturdy non-slip boots, and respiratory protection as your manual requires (WEN asks for NIOSH-approved dust masks or other respiratory protection during operation and cleaning); never wear loose clothing, scarves, jewelry or dangling drawstrings, and tie up long hair. Before every start, check that the guards, flaps, hoppers, discharge chute and any collection bag your manual requires are fitted and secured, and stop at once if the machine starts to vibrate abnormally, complete the full shutdown below and have the cause fixed before you restart. Never use your hand, foot or any body part to unclog the machine, even after it is shut down. Before you clear a clog, open the hopper or a panel, touch the knives, empty the bag, move or tilt the machine or leave it: on an electric hopper chipper, switch it off, unplug it from the outlet by the plug and wait until the blades have stopped completely, and on a leaf mulcher switch it off, wait until all motion has stopped and unplug it by the plug, never opening any electric machine before it is unplugged and still; on a gas chipper, follow your manual’s own shutdown sequence and every wait it prints: the engine off, the rotor and every moving part stopped completely, the engine and muffler cooled, the key removed where fitted, and every spark plug wire pulled off and secured away from its plug or grounded where your manual says so; on a PTO chipper, throttle to idle, disengage the PTO, turn the tractor off, remove the key, set the parking brake, wait until all motion has stopped and disconnect the PTO shaft before any service. Complete every model-specific step and minimum wait in the order your manual prescribes before any access, clear the blockage only with the method and tool it names, and refit every guard and any required bag before you restart. Use an electric chipper only with an outdoor-rated extension cord of the gauge and length your manual gives, plugged into GFCI-protected power, and never touch it or the plug with wet hands. Refuel a gas chipper outdoors with the engine off and cooled for at least the time your manual gives (Champion and MTD: two minutes), open the cap slowly, keep smoking, flames and sparks away, wipe up spills and never start it where fuel spilled; clear chips and leaves from the engine and muffler only after the full shutdown, spark plug wire off included, keep every cooling and combustible-material clearance your manual gives (Champion: 3 feet around the machine for cooling, 5 feet from combustible materials and dry vegetation), and never run it indoors or in a garage or shed, even with the doors open, because the exhaust contains carbon monoxide. Take breaks and stop when you are tired.