Addictive Additive: Blog

Our blog carves out a place for stories that connect with AM’s big future.

June 28, 2021

Elevators and Free Float : How small inventions can have huge impacts in our world

Elisha Otis's Elevator Patent Drawing
Source: The U.S. National Archives, Public Domain

When Elisha Otis patented the idea of the safety elevator in 1861, it seemed like a minor invention at the time, but this was soon to change the way we build buildings and change cityscapes forever. Now we assemble in tall buildings and spend a great deal of our time going up and down, some of us avoiding stairs completely!  This invention has forever altered cities, and now our buildings reach across the sky in an incredible display of architecture and engineering. 

Before the safety elevator, it was technically possible to build skyscrapers, but people didn't trust lifting platforms. Platforms were used for building materials exclusively but not for the public. They were often deemed unsafe and walking upstairs would get exhausting after five floors (imagine climbing five floors in a corset). The most attractive apartments were on the ground floor, and top floors were often considered low-income housing. For this reason, most buildings were never built over five floors. But this was all soon to change. 

With the arrival of the safety elevator, architects could dream bigger, make bolder statements, and push the limits to what was possible. The Equitable Life Building in downtown Manhattan completed in 1870, was the first office building to feature elevators from the design stage; it had eight stories. Soon people decided to build tall, and the top floors with incredible views began to become attractive to higher-income earners. It was not long before the invention of the penthouse came to be.

Buildings like the Empire State Building, boasting an impressive 102 floors at 381m, began to tower over cities thanks to the invention of elevators; cities soon changed into gigantic sky-sprawling concrete jungles. 

Fast forward to today's world, modern examples like the Burj Khalifa dominates with 154 floors at an insane 828m and is only functional thanks to its 57 elevators. And as elevators and skyscrapers have now long been the norm, new technology such as metal additive manufacturing is taking over and disrupting the manufacturing process in major industries such as aviation, automotive and aeronautical. 

But within additive, there are also constraints. One of the biggest problems you have is support structures —a much-needed component of the 3D printing process. Support structures are necessary to help support overhangs in structures and remove the heat away from the piece during the printing process, which could create structural imperfections. They are almost the "ugly stairways" equivalent of additive. 

Like pre-elevator buildings restricted by height, additive manufacturing is also limited by support structures. In addition to this, support structures require a great deal of material usage, increasing the cost considerably. You also have to factor in an increase in overall build time. In some cases, it can even take more to print the support structure than the overall part.  It is also worth considering all the post-processing time to remove the part from the support structures. 

In comes Free Float, an unassumingly powerful technology that SLM Solutions have just launched. Free Float can severely reduce or, in some cases, remove the support structures altogether. Added to this, you have a better surface finish, sharper edges, less internal stress, and overall better part quality. Buildings also received several design upgrades with the invention of elevators, as a stairway no longer bounds them. 

What designers and engineers are left with is the freedom to design, similar to what architects and engineers experienced with the elevator's invention. With Free Float, they can create completely free from restraints, achieve new heights, go bigger, go bolder. It is only a matter of time before we start to see the effects of a technology like this, but one can only be excited to imagine what is around the corner for additive with Free Float technology in play.