Case Studies



Case Study # 7



Aircraft Assembly F35 (# 2)

Aircraft Flex Mfg. (# 1)

Alumnia Processing (# 4)

Copper Refining (# 7)

Copper Rolling Mill (# 14)

Heat Exchangers # (9)

Heavy Equipment (# 6)

Injection Molding (# 8)

Mining Truck Assembly (# 10)

Naval Shipyard (# 22)

Nuclear Nutrino (# 12)

Nuclear Spent Fuel (# 11)

Nuclear Yucca Mountain (# 13)

Precast Structures (# 5)

Robot-Flashjet (# 3)

Shipbuilding (# 15)

Transformer Assembly (# 16)


Copper Refining

A leading international mining group uncovers Doerfer's AGV Wheelift technology for material movement to/from the acid tanks for the migration of copper ions from anodes to interleaved stainless steel cathodes forming plates of 99.99% pure copper.

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Copper Refining

Copper Acid

A consistent and repeatable manufacturing process in copper refining traditionally calls for a hard automation solution, however long distances, contamination with caustic acid dripping, parallel processing, close positioning, heavy loads, process equipment accessibility, and process disengagement led one manufacturer to evaluate the flexibility and responsiveness that an AGV solution would offer.

Cathode loading station


Cathode Copper Refinery AGV travel path station

Racks of anodes are lowered into an acid solution, interleaved with stainless steel cathodes. For 10 days, an electric current is sent between the anode and the cathode, causing the copper ions to migrate from the anode to the cathode. The other impurities, including gold and silver, drop off into the solution. This process forms a plate of 99.99% pure copper. An anode will produce two cathodes, each weighing about 280 pounds. The copper cathodes are the finished product.

Copper Refining AGV

AGV System

Continuous material movement made this a very active AGV system. The AGVs were required to handle all loaded and unloaded racks to and from the acid process interfacing to overhead cranes, gantries, and load perches.

Copper Refining migration tanks



CHALLENGE: Navigate tight quarters, uneven floor with slopes, high traffic areas, high magnetic fields, water puddles, and caustic acidic operating conditions.

SOLUTION: A shielded and sealed stainless steel AC servo driven Wheelift AGV fleet of five vehicles, each with enclosed self-loading capability for 80,000 lb payload and guided by inertial navigation technology.


  • Process equipment accessibility
  • Reliability with built in redundancy
  • Integral design for protection and safety

Each of the AGV Transporters has four on-center rotation axle assemblies allowing crab steering throughout the manufacturing process, providing close adjacent line of travels and minimizing load blocking zones. With their fluid equalizing suspension, the AGV's axles have interconnecting fluid lines that divide them into load sharing groups to assure that every wheel carries only its specific share of the load, regardless of variations, slopes, and irregularities in the floor surfaces.

Navigation is accomplished with Savant's non-invasive inertial guidance technology providing system flexibility and reliability, while supporting maintenance staff's requirements for an open architecture control system with real-time system monitoring and diagnostics capability.

Virtual Path


Flexible Assembly Tooling AGVs

The modular Wheelift chassis provides a degree of flexibility not attainable through other technologies. Wheelift Transporters and AGVs enable manufacturing flexibility with configurable work processes facilitating new design freedoms benefiting worldwide niche markets.

Wheelift Transporters and AGVs are manufactured in Iowa and are custom engineered to application specific requirements. Chassis and fixtures are available with load capacities to 500+ tons and deck heights as low as 18.5". Power options include diesel, LP gas, battery, and/or umbilical cord. Computerized all electric omni-directional drives are standard with individual axle ratings of 15, 20, or 30-ton.

Wheelift® is a Doerfer Companies technology. Doerfer engineers and builds application specific manufacturing machinery and systems. Operating from four North American locations with over 700,000 sq. ft. and 500+ employees, Doerfer offers an array of engineering and manufacturing resources and is NQA-1 certified. .

SUMMATION: Wheelift ultra heavy capacity AGV systems introduce a new realm of flexibility the copper refining and similar industries by being able to carry loads several times the size of conventional AGVs.


The following terms that are used through this website: Wheelift®, Uniload®, SynchroSteer®, StackAxle®, TrackAxle™ and OmniAxle are all trademarks that are exclusively licensed to Doerfer Companies.