Model 865 Vertical Compost Mixer

Model 865 is a twin auger vertical compost mixer with a mixing capacity of 740 cu. ft. and can hold a maximum load up to 18,500 lbs. Twin matching single flighted augers with several knife options are available for fast blending of compost materials. It is designed to efficiently and thoroughly mix materials such as municipal sludge waste and wood chips to produce quality compost. The low profile allows for several types of loaders to input materials without clearance concerns. It is available in truck, trailer or stationary. Optional conveyors allow for building compost piles. This vertical mixer works well with medium-sized composting operations.


  • Single pole tongue allows for a tight turning radius.
  • Trailer constructed of heavy-duty tubular  steel with built in scale mountings.
  • Heavy-duty hubs and spindles  designed for years of trouble free operation.
  • A wide selection of tire choices.
  • Rear bumper is standard equipment.
  • Short wheel base allows for tight turns and easy maneuverability.
  • Adjustable hitch clevis allows the operator to level mixer with most tractors to maximize mixer efficiency.
  • Heavy-duty, tubular trailer frame ensures long life and maximum scale accuracy.
  • Weigh bar scale or load cell mounting.
  • Load cell mounting comes standard with ROTO-MIX ball and socket type tie bars to connect the mixer to the frame. This feature eliminates side and end movement on the load cells which allows for scale dependability and accuracy.
  • Heavy-duty leaf spring suspension on 720 and 920 units.


  • Higher side discharge location allows easier loading of conveyors or elevator legs while maintaining a minimum mixer height.
  • Left and right discharge units available.
  • Low electric horsepower requirements.
  • Flexible motor mount designs to keep overall space requirements to a minimum.
  • Wide base scale frame.


  • Door—Wide door openings allow for fast delivery with easy hydraulic control while mixer is running.
  • Spouts—Gravity discharge spouts have no moving parts. Wind exposure is reduced.
  • Ladders to aid in inspection of mixing chamber.
  • Stainless steel liners for mixing chamber.

When mixing ingredients for a selected compost recipe, it is important to ensure a rapid decomposition to create a quality compost. By using a compost mixer, it will uniformly distribute nutrients and microorganisms throughout the compost pile. Roto-Mix vertical mixers range in size from three smaller capacity Single auger units ranging from 315 to 500 cu. ft. to nine different Twin auger mixers ranging from 320 cu. ft all the way up to 1300 cu. ft. These vertical mixers efficiently and thoroughly mix materials such as municipal sludge waste and wood chips to produce quality compost. Rear mounted conveyor builds compost piles and is fed from the rear gate controlled by the operator.

Twin Auger Compost Mixers are all available in Truck, Trailer or Stationary models. The 325, 425 and 505 models are low profile and offer fast processing of compost mixtures with a quick discharge requiring low horsepower with chain and sprocket drive. Models 625, 745 and 865 offer more capacity. Truck units offer variable displacement Hydrostat Drive System and FEPTO Drive is standard on front of the engine crankshaft. The trailer units have two speed PTO driven gear box with manual shifter. Hudraulic operated door and conveyor with four hoses. The larger capacity Vertical models 1105, 1355 and 1505 are avaiable in the H-Series equipped with variable speed hydrostatic.

GeneRation II Staggered Rotor Mixers

The rotor design lifts ingredients up to the side augers that move ingredients end-to-end for a fast thorough mix. Unlike the wedge point on other brands, our rotor lifts the material past the wedging point of the lower side auger, giving you a fluffier mixture while lowering power requirements. Total movement of material in the mixing chamber eliminates dead spots common in conventional auger mixers.

Particle Integrity

The ROTO-MIX system protects particle size with less grinding or compaction. Particle size and porosity are critical because it determines how well air can enter and diffuse into the composting mass.


With better air introduction and distribution, ROTO-MIX consistently produces quality compost by lifting the ingredients past the lower auger’s wedge point, resulting in a fluffier mixture that starts to compost faster.

Totally Mixed Compost

Our thorough mixing action eliminates dead spots, auger tunneling and corner pile-up giving a consistent balance of nutrients and microorganisms from the first yard of compost to the last.


Mixes all types of compost ingredients, solid waste, yard waste, food waste, sludge and amendments, animal manure and a number of others with consistency day after day.

Industrial Scale Check System

Load-cell mounting comes standard with ROTO-MIX ball and socket type tie bars to connect the mixer to the frame. This feature eliminates side and end movement on the load cells, which allow for scale dependability and accuracy.


Optional hydraulic folding conveyor up to 120″ long gives you ability to build windrows, static piles or load truck fast and efficiently. We also have a portable stand-alone conveyor for stationary models.


The forward pitch rotor design, adjustable UHMW wiper blades, and the rotation of the lower auger quickly and efficiently cleans out the mixing chamber.

Easy Access Rear Doors

The single lever latch makes inspection easy and desirable compared to other little latches or hardware.

Single Point Grease Bank

Allows quick lubrication from a single point. Heavy- duty drive assembly runs in an enclosed oil bath.

Lower Center Of Gravity

A lower center of gravity makes for a more stable unit when making windrows and less shock load when cornering.

Forward Pitched Rotor

The patented rotor lifts ingredients up to the side augers that move the ingredients from end-to-end for thorough mixing. The lifting action of the rotor eliminates wedging of the compost under the lower auger. Patented tumbling design reduces mixing power requirements.

Industrial Duty Drive Train

Spline shafts eliminate shearing of keys and gaulding of shafts. Heavy-duty chains and bearings extend life and reduce downtime.

Industrial Flighting

3⁄4″, 5⁄8″ and 1⁄2″ flighting available for lower auger to extend life. Top augers available in 3⁄8″ and 1⁄2″ flighting.

Flared Side

The flared side allows ingredients to tumble out of the rotor speeding up the mixing action and reducing the chance for ingredients to get trapped inside the rotor.

Full Scale Frame

Sturdy box frame construction with rectangular tubing for increased stability and weighing accuracy. Scale frame assembly allows scale frame to float independent of truck frame.