Below are various questions Virnig Manufacturing receives on a regular basis. Browse through the following questions and click on a question to see the answer. If you do not see your question listed below please contact a local Virnig dealer or call 800.648.2408.
Drum Mulcher Frequently Asked Questions
IS THE V70 DRUM MULCHER COMPATIBLE WITH MY LOADER?
The V70 Drum Mulcher requires a high flow loader with:
Shatterproof (polycarbonate) cab
30+ GPM flow rate
2,800+ pounds operating capacity
HOW DOES A DRUM MULCHER COMPARE TO A DISC MULCHER?
They both have advantages and disadvantages. Typically, drums are used in residential areas and discs used in unrestricted, rural areas with no houses or traffic. If flying debris is a concern, then a drum should probably be used. If the customer doesn’t care about the finished product and are in an unrestricted area, then a disc mulcher is usually preferred.
Discs are for speed and are much more productive and efficient for cleared area/time. They can process an entire tree in a split second and the mulched material doesn’t pile up.
Drums are more productive at processing felled material, leave less mess during initial knock down, produce a finer mulched finish and have better debris control.
Drums can get below ground level (great for stumps), discs can cut flush with the ground.
Quick Comparison Summary
Drum = Quality: slower, nicer finish, some debris control, diverse environments, mulch below grade, higher operating cost, more expensive upfront cost
Disc = Speed: faster, messier finish, debris uncontrollable, unrestricted environments, mulch ground level, lower operating cost, less expensive upfront cost
DOES THE V70 DRUM MULCHER COME TUNED TO MY LOADER FROM THE FACTORY?
The V70 DRM will come tuned for optimal drum speed and be ready to use from the factory within a GPM increment. The flow range choices (in GPM) are:
HOW IS THE V70 DRUM MULCHER TUNED TO A LOADER?
The Virnig V70 DRM uses a synchronous timing belt, wound around a motor sheave and drum sheave to get the drum rotor speed. This method doesn’t require any motor adjustment, special tools or having service tech come and tune the V70 DRM.
There are 10 different sheave combinations to match flow rate and get optimal drum speed. The sheaves have varying quantities of teeth. See the shave combination chart below.
Note: fixed and variable motors require different sheave combinations.
WHAT CUTTING WIDTH SHOULD I CHOOSE?
60” drum mulchers are more popular since they’re more maneuverable in tight spaces, draw less HP from the loader and spin up and recover faster than a 72” drum mulcher. When primarily clearing trees, most of the production occurs in the middle of the drum and having an extra foot of cutting width isn’t necessary.
72” drum mulchers process more material at a faster rate than a 60” drum mulcher This can be an advantage when working on larger job sites with a lot of ground vegetation to clear and where significant back dragging and ground mulching is required. The heavier drum handles larger material loads and provides more cutting momentum when grinding stumps and through thick vegetation. 72” drum mulchers are more expensive upfront and will likely cost more to operate and maintain.
DOES THE V70 DRUM MULCHER HAVE HYDRAULIC BRAKING?
No, the V70 DRM doesn’t have a brake. The drum rotor will continue to spin for several minutes before stopping. Operators should NEVER leave the cab until the drum stops spinning.
SHOULD I CHOOSE A FIXED MOTOR OR A VARIABLE MOTOR?
The Fixed Speed Bent-Axis Piston Motor (63cc max displacement) is the less expensive option for lighter vegetation and brush removal above ground. It will stall easier than a variable motor during heavy material loads, like when grinding stumps or mulching below grade, since it has less torque.
The Variable Speed Bent-Axis Piston Motor (85cc max displacement) is the most popular motor due to productivity gains when stump grinding and ground mulching. During heavy material loads, the motor smoothly shifts to max displacement and a slower speed to provide more torque.
WHAT PROTECTS THE HYDRAULIC SYSTEM FROM PRESSURE SPIKES?
The V70 DRM comes with a case drain line and a spindle oil vent to prevent motor seal and bearing adapter seal failure. In the event there is a spike in pressure in your hydraulic lines, the case drain will relieve the pressure and drain it back into the return line and back to the loader. If the case drain (third line) is not connected or if the line fails, then the case drain will release some oil to notify the operator. A properly installed case drain protected by a vent will save the work of replacing the shaft seal and save down time from unexpected maintenance.
SHOULD I GET SMOOTH OR BITE CONTROL DRUM ROTOR?
Here are some key differences between the two drum styles to help decide:
Ideal where significant ground contact is expected and when mulching below grade
Mulches entire pieces of vegetation at max cut depth and is more productive with smaller materials
Provides maximum energy transfer to the material
More likely to throw larger material and grab chunks
More likely for woody material to jam, since bite isn’t limited
Works well with steel planer and carbide teeth
Easier to keep balanced
Requires more HP from loader since bite isn’t limited
Lower upfront cost than bite control drums
Bite Control Drum
More productive and greater control during heavy, deep grinding in larger material
Controlling the cut depth when processing wood keeps the rotor working at greater efficiency and at a more stable torque load. Heavy wood use creates a high load in the drum and teeth and benefits from a controlled bite
AR450 bite control rings help maintain drum speed and prevent stalling by limiting the depth and amount of material the mulcher can cut in a single pass.
Smaller bites produce consistent chip size and finer mulch on the first pass
Less likely for woody material to jam
Rings are designed to feed material toward the center of the drum. Proper feeding toward the center contributes to better mulching quality. It allows for consistent and uniform processing of the material, resulting in a more finely mulched finish
Much more productive with steel teeth than carbide. Bite control doesn’t work as well with carbide teeth since these provide less suction off the ground and suction is needed when working in rocky conditions
Slightly heavier and rings offer extra protection to the teeth and tooth holder
Rings may wear unevenly and require drum rebalancing
Requires less HP from loader
Higher upfront cost than smooth drums
CAN THE V70 DRUM MULCHER MULCH BELOW GRADE?
Yes, it can mulch 2” below grade when the mulcher is rolled forward on the skid shoes.
CAN THE V70 DRUM MULCHER GRIND STUMPS?
Yes, the V70 DRM is very effective at grinding stumps and can grind them below grade.
HOW LONG DO THE TEETH LAST?
Tooth life varies based on many different factors. During testing, Virnig has seen steel teeth last updwards of 400 hours and carbide 600 hours.
The V70 DRM utilizes Quadco® teeth which provide proven performance and durability.
WHICH TOOTH OPTION SHOULD I CHOOSE?
There are three tooth options which can be mixed and matched on the drum. The optimal choice depends on ground conditions, ground contact required and chip size requirements.
Steel planer teeth are the most productive and provide the smallest and finest mulched finish. They can be resharpened and rotated 180 degrees for twice the life.
Carbide Planer teeth are a hybrid between the steel planer and carbide hammer. It provides high productivity and can handle minimal ground contact.
Carbide Hammer teeth are for significant ground engagement and will provide the largest chip size. They also require the most loader power to operate since they are pulverizing material instead of slicing and cutting.
For max productivity and the finest mulch without ground contact
Have two razor sharp edges to quickly slice through wood and pick up material off the ground
Made from high-grade alloy steel and heat treated
Reversible and need to be sharpened regularly to maintain high production
Stay off the ground and out of sand with steel teeth or the edges will dull quickly
Sharp cutting angle and curved body profile for higher productivity than hammer teeth with minimal ground contact
Requires no maintenance – no sharpening required
Abrasion resistant carbide tips for durability in rocky & sandy environments
Produce slightly larger wood chips than steel planer with similar productivity
For significant ground engagement in rocky and sandy conditions, less productive than planer teeth
Produces largest mulch and the least amount of ground suction – pulverizes and rips material instead of cuts
Requires no maintenance – no sharpening required
Ideal option if mulcher is primarily used to mix mulch into the soil
Most abrasion resistant option with lowest cutting performance and productivity
Requires more power from the loader to operate
HOW ARE THE TEETH INSTALLED ON THE DRUM FROM THE FACTORY?
V70 DRM ships with all 34 or 38 of the same tooth type installed on the drum (ex. all steel planer or all carbide). Virnig will not install different tooth types on the same drum at the factory.
If a customer wants alternating or segmented teeth, they have to order those teeth separately and install those themselves. Teeth can be ordered individually or as a whole drum tooth kit. Every replacement tooth comes with a 12-point bolt.
CAN I MIX TEETH ON THE DRUM? WHERE SHOULD I INSTALL TEETH?
Yes, tooth styles can be mixed on the drum as long as they’re installed in pairs & on opposite sides of the drum to maintain balance. There are many different ways to install teeth on the drum. For the segmented installation, operators enjoy having steel on the middle of the drum for high productivity and carbide on the outside for rock contact and less maintenance.
Here are the most popular tooth installation locations:
HOW DOES THE BITE LIMITER PLATE WORK?
The bite limiter plate can be adjusted to any point between 3/8” and 1-15/16” which increases or decreases the distance between the plate and the drum. The smallest chip size is achieved by adjusting the cutter bar as close as the slots will allow (approximately a 3/8″ gap from tooth to bite plate). A wider gap generally increases finished particle size. The steel plate can also be reversed to double the wear life.
IS THE PUSH BAR ADJUSTABLE?
Yes, the push bar can be manually set to three different positions for more or less drum engagement depending on the application.
IS THE PRESSURE GAUGE STANDARD ON V70 DRUM MULCHERS?
Contact a local Virnig dealer for the most accurate attachment specs, or call Virnig at 800.648.2408.
HOW DO I PURCHASE VIRNIG ATTACHMENTS?
Virnig sells mini skid steer, compact tractor, and skid steer attachments through a network of independently owned dealers throughout the United States and Canada. Call 800-648-2408 for assistance in finding a dealer or use the online Dealer Finder.
WHAT TYPE OF ATTACHMENT INTERFACE/HOOKUP DOES VIRNIG USE?
All Virnig skid steer attachments are manufactured with a universal mount to fit most skid steer loaders. The mounting frame is built to ISO 24410 and SAE J2513 standards.
All Virnig mini skid steer attachments are manufactured with a Toro®/mini universal mount, Bobcat® mount, or ASV® mount.
WHAT IS THE SETUP TIME FOR A VIRNIG ATTACHMENT?
Most Virnig attachments are ready to work right off the pallet.
To minimize setup time, Virnig Manufacturing requires the machine brand and model to be listed in every order for attachments with hydraulic components. This ensures proper hose length, routing, and coupler sizing. In addition, all hydraulic Virnig Attachments are tested for leaks and proper operation before leaving the factory. There may be specific scenarios in which additional setup time will be required.
HOW QUICKLY CAN I GET REPLACEMENT PARTS?
Most parts for Virnig skid steer attachments are available in-stock and can be shipped as early as the same day the order is received. Fabricated and back ordered parts are available with a reasonable lead time. Virnig uses several shipping options to provide timely and cost effective delivery to customers.
All Virnig parts and attachments are warranted for one year from the end user’s date of purchase, or the dealer’s date of first rental/demonstration. If the warranty period has expired, a sales receipt or first rental slip will be required for warranty consideration.
WHY DOES VIRNIG USE NITROSTEEL® CYLINDER RODS?
Virnig uses NitroSteel® cylinder rods because they are a superior performing alternative to chrome plating. The finish offers improved corrosion resistance and better grease retention.
Chrome plated cylinder rods can flake or pit and destroy the seals or other internal components; resulting in downtime and expensive repairs.
The questions and answers in this FAQ are provided for general information purposes only and may not be completely accurate in every circumstance, view full details. This FAQ is subject to change without notice.
Economical motor for mulching lighter vegetation above ground.
Provides more torque for productive stump grinding and mulching below grade.
Designed for heavy ground engagement and mulching into the soil.
Bite Control Drum
Helps maintain drum speed by limiting the depth of material being processed.
Monitor hydraulic operating pressure for max productivity.
Steel Planer Teeth
For max productivity and the finest mulch without ground contact.
Carbide Planer Teeth
For higher productivity and minimal ground contact.
Carbide Hammer Teeth
For significant ground engagement in rocky conditions.