MHS Builds Custom Multi Axis Positioning Crane and Hoist System for US Air Force

May 7, 2012 - PRLog -- The use of blast media is a clean and efficient way of stripping paint from aircraft during the refurbishing process.  US Technologies Inc, (UST) based ini Canton, Ohio has supplied the military with blast media and related services for over 30 years.  As a key component of this service, UST became involved in developing a media handling system that would provide better access to the plane and allow for a quicker and safer method of refurbishing planes.

In the past, the typical way to accomplish this task would be to use ground-based aerial work platforms such as scissor lifts or articulating man lifts.  These lift platforms would move around the plane itself while operators sprayed the blast media.  But this approach came with its own problems.  Jack Hinsdale, owner of Material Handling Solutions (MHS) based in Duncan, SC, explains:  “This was very time consuming and required a certain amount of clear floor space in order for the lifts to access the perimeter of the planes.”

So, instead of using the traditional man scissor lifts that operated from the floor, UST and MHS worked to develop a method that would instead allow for either a manned platform, or a cab fixed with a spray nozzle, to be carried around the plane. This platform, called the Aerial Multi-access Platform, or AMP, is suspended by an overhead crane, and in turn gives the operator complete access to every part of the aircraft.

The original concept and design for the AMP was inspired by the Stewart platform that is used in airplane simulators. MHS’ Hinsdale says, “The Stewart platform uses three pair of cylinders underneath a platform and mounted to a base.  The tops of the three pairs of cylinders are affixed in an equilateral triangular pattern to the upper platform with the bottoms of the cylinders mounted on the base rotated 60 degrees from the upper platform triangle, thus raising and/or lowering the cylinders in various measures allow the upper platform to be moved on multiple axes.  Since three points determine a plane geometrically speaking, the pitch, yaw, and roll achieved in flight is easily simulated.”

UST’s design for the paint stripping cab or platform is inverted from the typical Stewart platform, using hoists to lift and lower simultaneously from three separate points.  Hinsdale says, “Instead of using cylinders as with the Stewart platform, the AMP system uses six wire rope hoists positioned in the same triangular configuration.”

With the AMP design, and a cab or platform fitted to allow operators to blast media at the plane, the customer can do away with work platforms that take up space on the busy plant floor.  Hinsdale says, “The operator can literally fly from the cables in the cab or on a platform, around the plane, blasting media.” Supporting an operator demonstrated the complete flexibility of the AMP concept, and even inspired its application to heavier loads.  At Robins AFB in Warner Robins, GA, a key task on the base is to remove and replace the wing boxes from C-130 aircraft.  Hinsdale says, “The specific problem with the wing box was the need to pitch, yaw, and/or roll the wing box slightly to allow for easy insertion or removal from the fuselage.”

“The method used for many years was to use an overhead crane or a mobile crane, and rig it to the load as best possible.  This was explained to us as a very dicey operation.  It was not uncommon for the wing box to be in a bind with the fuselage.  The unbinding of this was achieved by lifting, lowering, hammering, or better described as “jimmying” the wing box free or into place.”

Once this problem was identified, the AMP system was recognized as having potential to be the perfect solution. It was at this point that UST and MHS partnered for the first application of the AMP concept in the area of materials handling. More specifically, this would be the first application to use the AMP system’s attributes to lift and control an actual load itself, as opposed to its previous blast media applications.

“By using these (AMP) principles to handle an actual product (the wing box), you create the ability for controlled multi-axis movement of the load itself. In the wing box application, the six hoists are attached to a lower triangular frame that is used to pick up the wing box”, continued Hinsdale. “So in addition to the standard up, down, left, right, forward, and reverse movements of the crane, you gain the motions of pitch, yaw, and roll of the load, as with the Stewart platform or the original AMP applications.  The wing box system was further enhanced by adding 360 degree rotation to the lower lifting fixture.”

The benefits were soon apparent.  Hinsdale says, “Even the very first time they used the system there were measurable improvements on speed, quality, and safety.  When you are given the ability to pitch, yaw, or roll an item (in a controlled fashion) when assembling it to another item, you gain a considerable advantage.”

But designing the mechanical parts and applying the complex algorithms of the system was not the total solution, as a very useful application also needed to be easy to control.  The team worked closely with Electromotive Systems, a Magnetek subsidiary, to come up with a specially designed radio transmitter suited to the needs and requirements of the AMP system.  Hinsdale reports, “The system has a crane and trolley mode which allows for standard forward/reverse and left/right.  Then, when the load is close to the correct position, the controls are switched into ‘AMP’ mode.  In AMP mode, the movements for pitch, yaw, roll, and lower/raise are all controlled with toggles that are labeled accordingly.

“The system is remarkably user-friendly and required very limited training”, he continues. “The operator simply controls all of the functions from a single belly box, with the designated motions on toggle type switches.  The sophistication is in the algorithms computed and controlled by way of the on board PLC.  The hoists are all DC motor driven, which allows for very precision positioning and tracking of the cables.”

MHS’ Hinsdale is now looking for new applications for the AMP material handling system. He says, “I believe the applications are limitless.  The primary qualification would be any lifting and mating or assembly, where manipulating the load is critical.  It would also be specific to loads that are of a high enough capacity to disqualify using a handling device or manipulator.  

“The industries that would seem to be the best candidates at this point would be aircraft manufacturing or maintenance, and ship building.  I believe that when crane and lift hoist people become aware of this product there will be a number of other industries identified.”

MHS works year in and year out with such companies as Fluor Corporation, Jacobs Engineering, BMW, Caterpillar, Freightliner, GE, KIA, Hyundai, Rheem, Trane, and many more of the leading manufacturers throughout the United States and beyond. Materials Handling Solutions is a leader in the Material Handling industry with over 170 years of industry experience, and soon you will be able to shop online at HoistandCraneDepot.com for all of you material handling needs.

Photos:
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