Disc Mulcher Vs Drum Mulcher

What's better, a skid steer disc mulcher or a drum mulcher? This question comes up all the time, so we thought we would share some insight into the topic. As you may have guessed already, the answer depends on where you are working, what you are doing, and what kind of skid steer or excavator you are using.

Key Takeaways

• Choose a skid steer mulcher attachment based on your host machine's capabilities as well as your job site needs.
• Disc Mulchers are more aggressive, can cut large-diameter trees and often require less hydraulic power from your host machine.
• Drum mulchers are less aggressive, but produce a smaller mulch and are safer to use in sensitive areas.

What Is the Difference Between a Skid Steer Disc Mulcher and Drum Mulcher?

The main difference between a disc mulcher and a drum mulcher is the design of their cutting heads, which determines their suitability for different tasks.

Disc mulchers have a disc-shaped cutting head that spins horizontally with multiple hardened steel teeth or carbide-tipped blades to shred trees.

Drum mulchers have a cylindrical drum-shaped cutting head that rotates vertically to turn vegetation into mulch.

Disc Mulchers - What To Know

Much like a large brush cutter, a disc mulcher turns a large round "blade carrier" that holds cutting teeth. The blade carrier sits inside a steel deck and is powered by a hydraulic piston motor.

Disc mulchers can have either one or two-blade carriers. If it has two blade carriers, we call it a "twin disc mulcher". Having two blade carriers requires two hydraulic motors, which increases the hydraulic flow needs, but also increases the performance.

Because disc mulchers turn horizontally, by design, they will send the cut mulch flying out from under the deck horizontally. The speed and trajectory of cut material can cover quite some distance. To help prevent flying debris, some disc mulcher manufacturers will add a deflector under the deck to help deflect the mulch downwards.

Much the same as drum mulchers and many brush cutters, most disc mulchers will have a push bar mounted on top of the deck. When cutting a tree, the push bar is used to push the tree forward and away from the carrier.

Disc Mulcher Attachments Advantages

So what are the advantages of a disc mulcher attachment? They are often lower cost, more aggressive, lower weight, and are compatible with more skid steers.

Lower Cost

Of course, the cost of any drum mulcher depends on the manufacturer, model and dealer. However, in general, a disc mulcher with a single disc is often the most affordable mulcher.

The average lower cost of a disc mulcher is definitely an advantage for those looking to save a little bit of money.

More Aggressive

Disc Mulchers have wide decks and large cutting areas. Single disc mulchers will often have 60" cutting decks but can be purchased smaller if needed, while twin disc mulchers cutting widths will go all the way up to 72".

Disc mulchers will have teeth on both sides of the disc as well as the edge allowing you to cut material as thick as 15".

Lower Weight

When comparing heads of similar size, disc mulchers are often lighter. Having a lighter mulching attachment keeps your center of gravity low, and reduces the hydraulic demand while maneuvering, leaving more power for the mulcher itself.

Compatibility

Disc mulcher attachments come in standard flow models, eliminating the need for a high-flow skid steer or excavator. This allows it to be used with a wider array of host machines on the market.

When Is a Disc Mulcher Better Than a Drum Mulcher?

Disc mulcher attachments are often the best forestry mulcher when working outside urban areas where you can be aggressive, cutting thicker trees. The aggressive nature of the disc attachment leaves a thicker mulch that is often spread out over a larger area.

Additionally, because of the lower weight and hydraulic power needs, disc mulchers are often a better option for equipment without high-flow hydraulics.

Drum Mulcher Attachment - What You Need To know

Drum mulchers are the big brother to the disc mulcher. With a drum mulcher, instead of spinning a blade carrier horizontally, the attachment is going to be rotating a drum that is held horizontally and rotating from top to bottom when viewed from the front.

The size of the drum itself depends on the make and model of the mulcher, however, a 60" wide drum with a 13" diameter is fairly common. The amount of cutting teeth will normally be between 30 to 40.

The drum will be driven by a piston motor, either directly or via a belt. Because of the size of the drum, the hydraulic needs of a drum mulcher are quite high, generally requiring more hydraulic horsepower than a disc mulcher. This means you often need high-flow hydraulics and high PSI to work a drum mulcher.

Because a drum is more compact than a disc, it carries less inertia as well. This means a drum mulcher may be more prone to slowing down while actively mulching, but also may be quick to spool back up to speed when backing off.

When Is a Drum Mulcher Better Than a Disc Mulcher?

Drum mulchers are often the best choice when you want a smaller mulch size, looking to mulch vegetation smaller than 8", or are wanting to grind stumps below the surface. Below is a video of Gary Power from Promac Equipment going over both the HSM and HSL Drum Mulcher.

Grinding below the surface

The geometry of the steel deck that houses the drum mulcher, combined with the rotation of the drum makes it possible to grind a stump down below the surface. This often adds value when you don't need to rent a stump grinder to clean up after you've mulched an area.

Smaller Mulch Size

For the finest mulch possible, a drum mulcher is your best option. Not only does the drum cut finer mulch, but it also deposits the mulch straight down, so you can keep it in a smaller area.

Working In Sensitive Areas

If you are often going to be working near sensitive areas, such as lakes, semi-populated areas, power lines etc. drum mulchers are often the best choice. Compared to a disc mulcher, the drum mulch deposits the mulch straight down rather than horizontally, reducing the chances of contaminating or damaging nearby structures.

Productivity of Drum and Disc Munchers

Drum Mulcher Productivity

The productivity of a drum mulcher can vary depending on factors such as the density and type of vegetation, terrain, and horsepower of the machine being used. It also largely depends on if you are selectively mulching areas or clear-cutting an area, what the terrain is like if the ground is wet and muddy, and what you want the final product to look like.

With that said, you will likely be able to clear around 1 acre per day with a drum mulcher working 8 to 10 hours under fairly easy conditions.

Disc Mulcher Productivity

Of course, the productivity of any disc mulcher is also closely related to the type of vegetation, working conditions, host machine, operating experience and technique and so forth.

In general, however, it is possible to mulch faster with a disc mulcher than with a drum mulcher when all else is equal. As a rule of thumb, 1.25 to 1.5 acres per 10-hour day is possible with a disc mulcher.

The Efficiency of Disc and Drum Mulchers

LANDOWNERS

For landowners that are clearing their land, primarily concerned with cost rather than impressing a customer, the disc mulcher seems to be the most efficient choice.

Assuming you are clearing a 50-acre lot and averaging 1.25 acres per hour, the total job will take 40 hours with a disc mulcher and closer to 50 hours with a drum mulcher. Being able to complete the job 10 hours faster will save you $100 to $150 in fuel, oil, grease and maintenance costs.

Business Owners

Most skid steer business owners are going to want to not only impress their customers with a fantastic finish but are also going to want to ensure they are profitable. Here is where the drum mulcher starts to make a lot of sense.

Assuming you have 50 acres of land to clear for a customer, it's likely to take 50 hours with a drum mulcher, and 40 hours with a disc mulcher.

Your job is going to take 10 extra hours to complete with a drum mulcher, but you are going to be able to provide a very fine mulch with an impressive finish. Are these extra 10 hours worth it? I think so.

Let's say your client is paying you $10,000 for this 50-acre land-clearing job. Regardless of the type of mulching head you have, your operational costs are around $70 per hour. Therefore your total cost to complete the job with a disc mulcher is $2800. with the slower drum mulcher, your cost would be closer to $3500.

This works out to an operating cost difference of approximately $700, or a decrease in the operating margin of 7% with the drum mulcher. But the question is, is this 7% difference worth it?

Understanding the trade-off

In my experience, with client work, this 5% to 7% operating margin difference is worth absorbing for the following reason.

• The fine mulch from your drum mulcher is more likely to impress your customer, giving you a better shot at landing more work in the future (it's all about reputation).
• You're more likely to land bids because you'll be able to operate in closer quarters to sensitive areas and have a lower impact on the surrounding environment with a drum mulcher.
• You'll be able to grind the customer's stumps below grade on request adding more value and making you more competitive.

Maintenance: Drum and Disc Mulchers

Maintenance considerations should also play a part in our discussion about mulching heads. Both drum mulchers and disc mulchers require some level of maintenance, but the amount of maintenance required can vary depending on several factors, such as the brand of the equipment, the conditions in which they are used, and how well they are maintained.

Notwithstanding the regular checking of and replacement of carbide teeth, below are a few special maintenance considerations for each type of mulching head.

Drum Mulcher Maintenance Considerations

Drum mulchers will usually have a few extra components compared to a disc mulcher which adds extra tasks to the maintenance schedule. These often aren't overly significant.

Drive Belt MAINTENANCE

Most drum mulchers will be powered indirectly by a hydraulic motor through a belt. This belt is not usually found in disc mulchers and adds some additional maintenance to the drum mulcher.

Generally, the drive belt will need to be visually inspected every week, and some of its related components will need to be lubed every 40 hours of use.

Replacing a worn drive belt is likely to be a 2-hour job that requires moderate mechanical experience. Luckily most drum mulchers will provide years of service before needing a drive belt replacement.

Disc Mulcher Maintenace considerations

Disc mulchers will often have fewer moving parts than a drum mulcher, the maintenance will often be less intensive and easier to perform.

One consideration with disc mulchers is the direct hydraulic drive system may be oil filled which needs to be inspected and filled regularly.

Gearbox Oil

If your disc mulcher does have an oil-filled gearbox, the manufacturer has likely provided guidance for how and when to check the oil level.

Surprisingly, sometimes checking and filling the gearbox oil isn't as easy as it seems. On some models of disc mulchers, you will have to unbolt the piston motor and lift it to check and fill the gearbox oil. This maintenance task may take up to an hour and require some mechanical experience.

Conclusion

I hope to have shed some light on the age-old disc mulcher vs drum mulcher question. We encourage you to read our blog about the best drum and disc mulcher for your skid steer. If you have any further questions or thoughts, you can reach out to me by email with the link in my bio.

If you want to learn more, call us today. Our staff would be happy to hear from you.