Choose Carousels -- For All the Right Reasons

May 1, 2002
Whether it's crossdocking, order consolidation, managing manufacturing components, staging work-in-process or retail storage, new carousels deliver high throughput in a small footprint.

by Christopher Trunk, managing editor

Vendors and consultants agree that carousels are too often overlooked in the rush to less automated storage options, but the new speed and utility that carousels bring to the assembly line, the dock door and to orderpicking cry out for notice. Innovative carousel designs and application ideas require a fresh look.

New applications, new ideas

“With inflation held in check, the only way companies drive profit is to lessen cost for raw material or increase worker productivity with material handling,” says Larry Strayhorn, president of Diamond Phoenix Corporation. “Every percentage gain in worker productivity drops directly to the bottom line.”

Carousels help in moving your operation from paper picking to higher-throughput, automated picking. Software controls and integration with WMS are linking carousels more closely to both orderpicking and order consolidation — “pick” and “put” environments. Strayhorn points to more carousels in putaway and returns.

Diamond reports it has two installations for Duracell and Lockheed Martin with high-speed, high-volume MaxTractor inserter/extractors. These robots perform eight transactions per minute with horizontal carousels. Trays of tested batteries are staged or sent to packaging at Duracell. Lockheed uses carousels at its central parts warehouse to store consolidated kits produced at manufacturing workstations.

“We are pioneering a virtual carousel workstation,” says Strayhorn. “Typically a worker picks from pods of two or three carousels. With the virtual workstation, if order volumes are low, software and controls are reconfigured so one worker picks from six, eight or 12 carousels.” With high-volume orders or in seasonal times, the buyer can shrink pods to just one worker per carousel by adjusting controls.

“With September 11 issues and the economic downswing, we’ve targeted pharmaceutical, electronic and aerospace/military industries — those less affected by economic changes,” says Jeff Peters, product manager for Hanel Storage Systems. “We recently installed carousels and vertical lift modules to consolidate spare parts for aircraft maintenance at a Midwest Air Force base. Space savings was important at the base warehouse, as well as solving lost-part problems and mispicks.”

Carousels are supporting retail. In Gallman, Mississippi, an automotive part distribution center for Discount Auto Parts supplies retail outlets. There, a two-level pallet carousel stores the faster-moving SKUs. A gantry robot lifts a layer of one SKU off a pallet in the carousel and places it onto another pallet on a takeaway conveyor. The palletload being built is an order for one store. “Before this, a store had to order an entire palletload of one SKU, but this carousel innovation now lets stores keep less inventory and more variety of SKUs on hand,” says Dave Simon, product manager, horizontal and vertical carousels for White Systems. “Smaller inventories both at the store and distribution center justify the system.”

“Apparel retailers have seasonal inventories that, when out of season, are stored in back rooms, typically in every which way in a store room,” says John C. Fink III, director of marketing for J&D Associates. “We can take 115 linear feet of apparel bar and put it into a carousel for garment protection and access. The carriers are adjustable for garment height and with shelves, so you can pack even more children’s clothes or shoes into a unit.”

Technological highjumps

A bright, new example of carousel innovation is the Model MVC 2700 vertical carousel from Knapp Advanced Technology Engineers. It may represent a breakthrough in orderpicking. The machine divides a typical vertical carousel into several independent modules, about 1.5 feet wide depending on product size. While the worker picks from the first module, the carousel identifies the next pick and rotates the adjacent module to present the next SKU to the worker. “With carousel segmentation, I see vertical carousels springing back into demand,” says Stan Kotowski, sales manager for Knapp. “In years past, buyers were deterred by significant cost for a machine that picked slower-moving items. But, now, future verticals can offer faster distribution speed, light-directed picking, cube analysis, smart slotting and security.”

The MVC’s pick-to-light display identifies the correct bin location, divided container location and number of items to pick. Total width is six or seven feet and offers up to 2,700 SKU locations per module at approximately 200 lines per hour.

“We suggest placing a takeaway conveyor in front of the carousel, allowing batch picking with a light bar showing the worker into which tote to put the items,” adds Kotowski. Knapp has installed these units for pharmaceutical distributors filling narcotic drug orders and for high-end jewelry distributors. “If you’re using the MVC for orderpicking lower-cost items like cosmetics, the machine transports vertical carousels into new horizons for higher-volume distribution,” says Kotowski.

Here’s a snapshot of some current carousel innovations:

J&D Associates. The company now offers AC drives for its vertical carousels that yield smoother motion and more precise stopping. New PLC controls make it easier to network with the buyers’ inventory or shop floor control system and provide a worker-friendly interaction with the carousel. The operator needs only type in a part number and the right carrier arrives at the workstation. J&D offers units with 12,000-, 20,000- and 30,000-pound capacities.

“Manufacturers position our carousels close to the manufacturing line to shorten set-up time for machinery and to simplify handling for curing manufactured goods,” says Fink.

Webb-Triax. A new horizontal, bottom-drive pallet carousel supports multi-level-column loads between 8,000 and 18,000 pounds, and up to 30 feet high. “It’s like a rotating storage rack designed to handle typical-size 1,000-, 2,000 -and 4,000-pound loads,” says Fred Cirino, sales manager for Webb-Triax. “We’ve located a machine at our receiving dock to sort goods for different locations in the plant.”

Use it to crossdock at distribution centers, to sequence work-in-process for an assembly line, to cure rubber and window products, or to quarantine goods until they pass inspection. Automotive is another application for sequencing work-in-process with engine blocks, transmissions, etc. Either lift trucks or robotic inserter/extractors service the carousel.

“We’ve quoted the machine to hardware distribution centers for building palletloads for retail stores — staging pallets on a third shift by delivery route so orders are ready when trucks pull in the next morning,” says Cirino. Returns putaway at the receiving dock is another smart application.

Hanel Storage Systems. A new microprocessor, Model MP12D, better tracks part numbers, bills of material and kits. It links multiple carousels with one processor. Also a new Rotomat S Module vertical carousel stores up to 1,650 pounds per carrier at heights from 10 to 30 feet.

Diamond Phoenix. The new DirectPick is pick-to-light software and hardware for carousels. “It’s a flexible system that lets you configure the carousel for discrete, batch and cluster picking,” says Robert Rienecke, vice president of marketing for Diamond Phoenix. DirectPick runs on Windows NT2000 workstations or servers and integrates with your existing orderfilling and WMS software.

The Twin Bin carousel configuration presents two pickfaces at a time to the worker, doubling the number of storage locations a picker can reach. “If you’re slotting items into a family-pick or batch-pick scenario, having two pickfaces means less carousel rotation and idle time for workers between picks,” says Strayhorn.

Leveraging your carousel

Carousel experts suggest these techniques for increased productivity and wiser design:

• Perform an SKU volume analysis. How many orders do you have? Understanding your business’ volume, quantity and physical size of items makes for best slotting decisions in both carousels and gravity flow rack. Diamond Phoenix.

• Pallet carousels can function like an automated storage and retrieval machine to store 30 to 100 pallets. Pallet carousels can fit nicely into most docks. “Buyers are sometimes reluctant to spend money on carousels, but they are easily justified with more accurate orders, better customer service and faster picking/putaway,” Cirino. Webb-Triax.

• Reslot it frequently, maybe as often as every three months. “You can’t expect an initial slotting to work forever, on this or any storage equipment,” Rick Frye, vice president, sales and marketing. White Systems.

• With inventory management software, cube use, picking speeds and throughput are tremendously increased. Remstar.

• Make carousels an integrated part of your process, not standalone units. Load from one side and extract from another. Specify carousels with openings on multiple floors for storing work-in-process, or for replenishing on one floor and picking from another. J&D Associates.

Daniel Frampton, a consultant and project manager for Operations Concepts Inc., suggests you arrange fast movers in the Golden Zone and configure horizontal carousels in a semicircular pod around a workstation. Frampton advises bottom-drive units for heavier loads and seismic applications as well as top-drive units for lighter loads. Twin-bins can double the number of bin locations and improve selection. Lastly, he suggests horizontal carousels for high pick rates and verticals for overhead space use and security.

Containers make the carousel

Ken Beckerman of Flexcon Corporation says containers play a vital role in a carousel’s success or failure. He offers these tips:

• Containers should fit within 1/4" of carousel width for maximum cube use. Use one container per shelf for most parts and another container for large items.

• Containers must divide in length and width with lockable dividers so parts don’t move when the carousel rotates.

• Containers must handle the push/pull motion at full load. Containers should last the life of the carousel.

Beckerman advises that for ergonomics and safety you look for containers with a 50 percent open front for easier picking and those with drain holes in case sprinkler water flows into the unit.

For fire safety, code ratings should be UL Flame Class 94HG.

Vertical carousels can be fitted with electrostatic dissipative containers to safely store parts for electronics applications.

Custom containers make for denser storage for surface-mount technology reels used to manufacture printed circuit boards.

“We pump nitrogen into vertical carousels, keeping electronic components clean. Before this, all the reels for one of our manufacturing customers were stored in open air. Parts were susceptible to dust and dirt,” says Peters of Hanel.

Differentiating vendors

There are many carousel vendors, and each can specialize in particular industries and product storage. Here is how some vendors see their strengths:

• “We have full-pallet carousels with multiple levels, not just single-level horizontal units.” Cirino, Webb-Triax.

• “We’re a carousel innovator with key concept developers who seek new ideas for carousel applications when working directly with customers. One example is using two pick carousels and some gravity flow rack to consolidate orders into a third put-carousel. The idea eliminates conveyor sections, reduces manual labor, consolidates on the spot and pays for itself in a year or less.” Frye, White Systems.

• “Our service organization is top notch. We offer spare parts and technicians in regional service centers for speedier repairs. We train our dealers in how to use and service carousels.” Ed Romaine, director of marketing for Remstar International Inc.

• “We have 10,000 vertical carousels in the home center market, in both commercial and industrial settings, and we offer problem-solving applications for managing and protecting print cylinders.” Fink, J&D Associates.

Consultants can identify vendors with the right technology for your application. Daniel Frampton of Operations Concepts says consultants can create alternative designs that build carousels into the “big picture”; conduct and evaluate competitive bids; keep project and budget on schedule, and train workers and provide service both before and after installation to smooth the transition to automation.

Looking ahead for carousels

Vendors and consultants see a bright future. Targets include building kits with carousels for replenishing retail store shelves and in applications where handling multiple size cases in random fashion are important. You’ll see more carousels in flexible manufacturing operations in electronics and tool and die industries. Heavy-duty vertical carousels will sprout up in retail outlets to store vinyl products and wire reels, spa tops and swimming pool liners.

Industrial applications will include print cylinders and ceramic molds. Vendors predict there’s a big market for cosmetics, health and beauty, prescription drugs, medical device manufacturing and electronics.

Bringing a broader horizon to your orderpicking mix is easier than ever now with the new flexibility and efficiency that cutting-edge carousel technology delivers. John Fink of J&D Associates says, “Keep your mind and eyes open for wise applications of carousels.” MHM

Meet Your New (Vertical) Postal Carrier

MHM first reported on a vertical carousel proposal for retail parcel delivery for the U.S. Postal Service in 2000. USPS just implemented the carousels at two retail site in April in a pilot program with Northrup Grumman. “The post office is developing a cost-and-decision analysis for return on investment with these machines,” says Robert Laybourn, marketing manager for Postal Systems, Northrup Grumman. USPS hopes these carousels may shorten lines at postal counters and allow more customer convenience.

“With the commingling concerns of biological contamination, health and safety of postal workers, losing money and raising postal rates, the USPS is looking at capital expense automation that can save on costs,” observes Laybourn.

The MIRS-brand carousels provide automated mail pickup for customers who are away when the postal carrier calls. The carrier leaves a unique, preprinted, bar-cod

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