What’s the difference between a skid steer disc mulcher and drum mulcher attachment? It’s a question we’re consistently being asked since we introduced the V70 Tree Disc Mulcher in early 2020. In this article, I discuss performance, costs, options and other differences between these two skid steer mulchers to help you decide if either is right for you.
SKID STEER MULCHER APPLICATIONS
Mulching can be a profitable service for forestry and landscaping professionals. Here are the most common applications where skid steer mulchers are being used today:
- Land clearing for private and public property
- Site preparation and lot clearing
- Pipeline and transmission line maintenance
- Forest management and wildfire prevention
- Trail and road overgrowth clearing
- Storm damage and disaster cleanup
SKID STEER MULCHER PERFORMANCE
When choosing any mulching attachment, it’s important to make sure it matches the machine’s capabilities to ensure it can operate efficiently. The machine needs to have the necessary high-flow hydraulics and it needs to be able to handle the weight of the attachment. Below, I discuss cutting capacity and capabilities of each skid steer mulcher.
Skid steer disc mulchers have a larger cutting capacity. You’ll typically see a cutting capacity of 14” diameter trees. For drum mulchers, you’ll typically see an 8” or 9” capacity. “High flow skid steer drum mulchers will cut 8” diameter trees continuously. Operators can cut bigger trees than that, but it’s not advised. It doesn’t make sense to mulch any material larger than 8”, because it takes too much time. It helps to have someone go in beforehand to cut down the bigger trees and remove them before going in with the mulcher,” said Craig Erpelding, from US Equipment Broker.
Tree Clearing Methods & Productivity
Disc mulchers have the ability to pull whole trees into the deck, mulching them to pieces within a few seconds. This is called the “cut and feed” method. Lastly, the stump can be mulched to the ground.
Both types of mulchers have the ability to reach as high as comfortably able and cut the tops off trees. Then the operator would mulch the stump to the ground using multiple passes. Lastly, the top of the tree can be mulched while lying on the ground. Another similar technique is cutting a tree near the bottom and taking multiple passes as the tree lies on the ground. This is a safer but more time-consuming method.
Disc is more difficult to bog down than a drum. Heavy disc weight coupled with a piston motor helps maintain inertia and momentum when cutting thick trees and brush. Overall, trees can be cleared a lot quicker, which results in higher productivity when compared to a drum mulcher.
Disc mulchers will grind stumps flush with the ground and drum mulchers can mulch stumps below ground. Erpelding said, “The biggest difference here is you can mulch 1-2” into the ground with a drum mulcher, allowing you to mulch stumps and roots below grade. You can even plant right into it afterward because it’s bringing up the topsoil and mulching the material into it.”
Do you want more wood chips or wood chunks? A drum mulcher will leave a finer finish (smaller wood chips) in initial knockdown and produces less initial mess. Disc mulchers can leave a groomed finish, but it will require the operator to go back and re-process any larger material. Keep in mind that excessive ground engaging may rapidly decrease the life of the cutting teeth.
SKID STEER MULCHER COSTS & OPTIONS
Disc mulcher skid steer attachments are less expensive. Most high flow disc mulchers fall into a $22,000-$29,000 price range and have a 60” cut width, while most high flow drum mulchers fall into a $33,000-$43,000 price range and have a 50”-75” cut width. Pricing will vary depending on width, the manufacturer chosen and the different options discussed below.
Skid Steer Disc Mulcher Options
The motor is the most expensive part of the mulcher, and they either have a piston motor or a gear motor. Gear motors are usually a few thousand dollars less upfront, but productivity and efficiency will be sacrificed. A piston motor is the highest performing motor available. It will have quicker recovery time, higher disc speed and more torque than a gear motor. We only use piston motors on the V70 Tree Disc Mulcher to deliver more torque and the disc spinning while other mulchers may bog down or stall.
Quadco® four-sided steel teeth come standard on the V70 Tree Disc Mulcher. These teeth can be resharpened and are rotatable and replaceable. They will cut wood more efficiently than carbide since they are sharper and more aggressive. We don’t offer carbide teeth for the Disc Mulcher at this time.
PRO TIP: Similar to a teeth on a chainsaw, operators must keep teeth sharp to maintain cutting efficiency. Keeping the teeth sharp will be easier on the loader and the mulcher motor. If the teeth are dull it will tear and shred material rather than cutting through it like butter.
Skid Steer Drum Mulcher Options
A drum mulcher attachment will either have a variable (two) speed piston motor or a gear motor. The piston motor will have quicker recovery time and provide more torque. The piston motor automatically adjusts to maximize rotor speed & torque to changing material loads.
For lighter material loads, higher RPM means more bites per second and finer material shredding. With heavier material the mulcher delivers more rotor torque, keeping the rotor turning when other mulchers may stall. “When mulching dense material, the motor will automatically shift to a lower speed and for lighter material it will shift to a higher speed,” said Erpelding.
There are three different drum options in this industry - smooth, paddle style and depth control. “The depth control drum has metal rings around it which prevents it from going into the ground and will work best with knives,” said Erpelding.
There are also two main tooth options - knife and carbide. These will allow users to make different styles of cuts depending on application. “The right tooth combination depends on the material you’re mulching. What’s nice with a drum mulcher is you can run all carbide, all knife or 50/50 knife and carbide or any combination you want. Knives are about 2-3x cheaper than carbide,” said Erpelding.
Most of the maintenance time goes toward maintaining the teeth. “Most people run carbide on drum mulchers to start. Then they switch to steel knives, since knives are about 2-3x cheaper than carbide,” said Erpelding.
The steel teeth on most disc mulchers, including the V70 Tree Disc Mulcher, can be rotated and resharpened, resulting in a longer service life.
Drum mulchers are safer to use when mulching in urban environments - specifically, near homes, buildings, utility lines and busy roads. “They will push most of the material back toward the ground and not away from it, like a disc mulcher,” said Erpelding. Since the drum is exposed on the back side, there’s a chance material will be thrown behind the skid steer. It’s vital to keep bystanders away from all mulching attachments in operation to prevent injury.
Disc mulchers will throw most of the material from the front and throw it further than a drum mulcher. Keep this in mind if you’re planning on mulching near buildings, homes, utility lines and busy roads. Either type of mulcher can launch material a long way and will be dangerous for bystanders.
Debris, rocks and chips will ricochet toward the operator. For operator safety, all mulcher manufacturers require installing shatterproof cab windows and some advise using a falling object protection system (FOPS) for operator safety.
Some skid steer drum mulcher motors contain a displacement screw which will require adjustment by the attachment owner, manufacturer or dealer. The screw must be adjusted and then “locked in”. The minimum displacement for drum mulcher motors needs to be adjusted for the GPM (flow rate) of the loader and the desired RPM of the mulcher rotor.
This step is crucial because insufficient RPM will greatly reduce the productivity of the drum mulcher, while overspeeding can cause serious damage to the motor and teeth. “I can set up customers with a mulcher right from the factory, so they have the right couplers, and motor is tuned correctly,” said Erpelding.
A skid steer disc mulcher works with a variety of high flow loaders without needing to adjust the mulcher motor each time a loader with a different flow rate is used. Attach the disc mulcher to the loader, connect couplers and the operator is ready to mulch.
MANEUVERABILITY & VISIBILITY
Drum mulchers have a slight advantage for both maneuverability and visibility. They’re more compact than a disc mulcher. The depth is about the same as a dirt bucket which results in better maneuverability. It’s also easier to maneuver in densely wooded areas. For drum mulchers, operators can see exactly when the drum is hitting the ground. There isn’t a deck limiting the operator’s view.
DISC MULCHER VS DRUM MULCHER CONCLUSION
Skid steer mulchers are great at performing in areas they're best suited for. Instead of one being better than the other, each style has its own advantages that will aid in some applications more than others. The more you know about your application and your desired end result, the easier it will be to choose a skid steer mulcher for your operation.
If you’re interested in learning more about Virnig skid steer brush cutters and mulchers, get your copy of The Ultimate Guide to Skid Steer Brush Cutters. It’s full of helpful tips and information for getting the most out of a cutter.