The Magswitch. The switchable magnet developed by Magswitch Technology differs from the traditional magnets used everyday by welders. It is not an electromagnet, a popular welding accessory used throughout the fabricating industry, in that the Magswitch is a device that allows a magnetic field to be turned “on” and “off” mechanically like an electromagnet, but without the need for ongoing power to sustain a strong magnetic field. Because external power is not required, problems such as arc flow are lessened. Energy costs are reduced.
The Magswitch is not a permanent magnet as its magnetic holding power can immediately be turned off and does not have lingering, residual holding forces. Typically, permanent magnetic tools are kept on all the time. As the day progresses and welding operations take place, the magnets collect metal debris that can never be fully removed, says Chris Chivers, Magswitch Technology’s general manager for welding, fabrication and heavy lifting. This issue makes the tools difficult to use and limits their holding power.
Magswitch technology can collapse the magnetic field when the tool is turned off. This allows the debris to immediately fall away and helps to keep the tool clean. When off, the tool can be safely positioned before it is turned on for precise handling when fixturing steel in various positions required for welding even complex components.
Holding capability
The company offers a variety of units that can be positioned in a multitude of angles to make welding easier, safer and more precise. They also come in a vast number of holding power strengths for use with a variety of workpiece sizes. The tools can also be used with other Magswitch Technology products such as a magnetic lift to help move heavy or awkward workpieces to the proper location for welding.
An individual Magswitch tool can hold about 250 times its own weight, says Chivers. One typical version weighs less than 200 g, but can hold more than 50 kg. The technology allows large sheet metal leveling in seconds, allows for true sheet de-stack without any sticking, and offers cordless heavy lifting for hard-to-reach areas.
Because welders only have two hands, activating the Magswitch is also made easy. There are many different methods to turn on the unit, such as a manual knob or T-handle like those used on the company’s welding clamps, workholding clamps and magjigs (magnetic jigs). Pneumatic actuators can actuate individual tools or many of these devices at any given time.
Hydraulics also can be used to activate tools, as can electrical motors and solenoids. For example, the Massachusetts Institute of Technology (MIT) uses tiny motors to activate the Magswitch tools in use in experiments with the university’s self-reconfiguring robotics project.
According to a Magswitch website testimonial from Keith Kotay, a scientist at the Rus Robotics Laboratory, MIT, “Magswitch products are being used as a grip and detach system in [its] self-disassembling cube project and this provides significant benefits over and above electromagnetic systems in terms of energy consumption as it does not require constant power to maintain magnetic hold …”
Switching technology
Magswitch has a patented switchable magnetic technology that Chivers says is “changing the way things are done” across a range of industrial efforts. Magswitch technology improves traditional magnetic applications and opens completely new uses and innovations. For instance, the technology is much stronger when used on thinner metal and adds increased safety and productivity in industrial solutions.
A fundamental difference between the types of magnetic systems is that traditional magnetic technologies have limitations in performance due to their core design. This translates to heavier, harder to operate and limited performance, especially on thinner materials, making them less safe, Chivers says. Magswitch design actually achieves higher performance from a lighter product through its designs.
The heart of the Magswitch patented technology is the use of two magnetic discs, with diametrically opposed polarities, placed within a specifically designed ferromagnetic housing. According to Chivers, the bottom disc is anchored in the housing, and the second disc is placed above and is “switched” by rotating the disc 180 degrees to either align similar polarities (on) or turned back in the opposite direction so that the polarities are opposite (off).
“In the on position,” Chivers says, “we achieve between 125 percent to 160 percent more power than the sum of the two magnets on their own. In the off position, the magnetic field is collapsed and the tools stay cleaner and are easily positioned before turning back on. This power completely surprises people when they first experience it. This technology allows us to achieve this power with an overall smaller, lighter tool, than traditional magnetic technology.””
Field control
To explain this capability, Chivers says that traditional magnetic technology is known as “deep field” technology. This is in reference to the magnetic flux field that is broad and circular in pattern as it travels from the north pole to the south pole of the magnet.
While these magnetic fields have reasonable power characteristics, they have strength limitations because it is not a focused force, he says. A big magnet used on thinner steel will actually not be very strong. Too much of the magnetic flux goes through and beyond the target in broad circular patterns. That kind of magnet needs thick metal in order to be used at its potential power.
“Because of our design, the magnetic flux pattern looks and performs differently than any other standard magnetic product,” Chivers says. “Instead of a broad circular pattern, the magnetic flux is tightly concentrated close to the tool. We call this ‘shallow field’ power. Because we control the natural flux nature of a permanent magnet, we can achieve exceptional power on thick or thin metal as we target more magnetic force into the targeted material. Arc blow is a condition where a magnetic field influenced the arc stream in welding – it becomes impossible to weld when this happens. Welders notice that the ‘arc blow’ effect is minimized with Magswitch because of the tightly concentrated magnetic flux pattern versus traditional magnets.
“For the welder, shallow field power means they can quickly fixture weld setups with extraordinary power,” he continues. “They can align and set up light- or heavy-duty projects quickly. We call our tools ‘clamps on steroids.’ In many cases, a two-man job can become a one-man job when these tools become a powerful ‘welder’s helper.’”
For example, in shipbuilding applications, Magswitch Technology has several magnetic tools used to fabricate multiple components on a ship. Magswitch tools are changing the way stiffener, bulkhead and plate fabrication are currently handled by eliminating many time-consuming procedures like using “dogs and wedges” for clamping and framing sheet metal fit-ups.
Because the magnetic tools allow for proper positioning of metal components, accuracy can be improved, eliminating the need for hours of post-process grinding. “Time to complete” and “cost to complete” are dramatically reduced by shipyards that now use Magswitch technology, says Chivers.
The company’s goal is to start with simple magnetic tools for fixturing in fabrication and evolve and scale up that technology into a multitude of industrial applications and opportunities. Examples include switchable welding grounds, lifting magnets for a variety of steel handling solutions, magnets that can be integrated into a multitude of OEM intellectual property ideas, magnetic drills, shipbuilding tools, customized end-of-arm tooling, and fixturing tools for robotics and automation.
“For thick, thin or irregular shaped steel, the possibilities of scaling Magswitch technology into so many areas known, and those yet undiscovered, is very exciting,” says Chivers.
