Model 620-16 Rotary Industrial Series Compost Mixer

Compost Mixer Brochure PDF

The 620-16 horizontal rotary compost mixer has a mixing capacity of 620 cu. ft. and can hold a maximum load up to 17,500 lbs. It is designed to thoroughly mix materials to ensure rapid decomposition to produce quality compost. This rotary compost mixer, equipped with the patented GeneRation II Staggered Rotor Mixer, will uniformly blend materials in a tumbling action that does not pack material and helps introduce air into the mix. The rotor lifts the material past the wedging point of the lower side auger, resulting in a aerated mixture while lowering power requirements. Total movement of material in the mixing chamber eliminates dead spots that are common in conventional auger mixers. Optional conveyors allow for the discharge and distribution of mixed nutrients with microorganisms into static compost piles or windrows. Available in truck, trailer or stationary units. This size of mixer works well with medium to larger composting operations.

Roto-Mix processing COIR

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.


Illustration Specifications Drawings

Model Description540-14620-16720-16920-18
Maximum Mixing Capacity (cu. yd.) *** 16.7 23 27.8 34.1
Maximum Mixing Load (lb) *** 17,500 17,500 20,500 26,100
Unit Weight (lb) Truck Installed 13,650 16,380 19,975 21,685
Unit Weight (lb) Trailer w/Tires 15,400 18,130 22,125 25,085
Unit Weight (lb) Stationary w/o Motor 13,360 16,090 18,655 20,485
Power Requirement (hp) Truck 230 230 230 250
Power Requirement (hp) Trailer 110 120 130 140
Power Requirement (hp) Stationary 50 50 50 40 / 75
Mixer Length (in) 170 218 223 232
Mixing Chamber Length (in) 144 192 192 216
Length Hitch to Tire Center (in) 171 182 185 1⁄2 193
Length Cab to Axle Center (in) 108 138 144 156
Overall Length–Trailer (in) 226 278 278 303
Overall Length–Truck (cab to bumper) (in) 181 229 235 262
Overall Length–Stationary (in) 182 1⁄2 230 1⁄2 234 250
Overall Width–Folded Spout (in) 112 112 115 122 3⁄4
Overall Width–Stationary (in) 106 1⁄2 106 1⁄2 110 118 3⁄4
Overall Width–Mixer Only (in) 106 1⁄2 106 1⁄2 110 118 3⁄4
Overall Width–Optional Conveyor (in) 140 140 145 172
Overall Height–Trailer* (in) 110 1⁄2 110 1⁄2 121 130
Overall Height Mixer / Truck Frame / Ht. (in) 116 / 36 116 / 36 119 / 36 135 / 36
Overall Height Mixer–Stationary (in) 85 1⁄2 85 1⁄2 89 1⁄2 101 3⁄4
Overall Width of Tires–Trailer (in) 94 94 96 96
Overall Width of Tires–Truck (in) 96 96 96 96
Discharge Hinge Height Trailer (in) 45 45 51 59
Discharge Hinge Height Truck (in) 51 51 52 56
Discharge Width (in) 46 1⁄2 46 1⁄2 46 1⁄2 46 1⁄2
Thickness–Bottoms (in) ** 3⁄8 3⁄8 3⁄8 3⁄8
Thickness–End Plates (in) 1⁄4 1⁄4 1⁄4 1⁄4
Thickness–Sides 7 ga 7 ga 7 ga 7 ga
Top Auger Flight (in) 3⁄8 x 24 OD 3⁄8 x 24 OD 3⁄8 x 24 OD 3⁄8 x 24 OD
Lower Auger Flight (in) 3⁄4, 1⁄2 x 24 OD 3⁄4, 1⁄2 x 24 OD 3⁄4, 1⁄2 x 24 OD 3⁄4, 1⁄2 x 24 OD
Rotor Diameter (in) 72 1⁄2 72 1⁄2 76 1⁄2 84 1⁄2
Rotor Bar Options 5,6 5,6 5,6 5,6
Drive Chain–Auger Drive ** #80H-100-120 #80H-100-120 #80H-100-120 Hydrostatic
Drive Chain–Rotor Drive #140 #140 #120-(2) #180

*Tire size may vary in height. Unit weight, listed most common option packages. All dimensions and specifications are subject to change without notice.

**Other options available.

***Maximum mixer capacity can be reached by volume or weight. By volume, each rotor bar should always be visible at the peak of the rotor cycle. By weight, when maximum load capacity is reached.