Prototyping Steel - A Continuous Steel Stair

Prototyping Steel was a class led by Matt Hutchinson from PathFab at California College of the Arts during the Fall 2015 semester.

We worked in collaboration with Autodesk Pier 9 in San Francisco to fabricate our steel components.

Assembly and welding took place at California College of the Arts.

The work being shared was done by Gabriel Ascanio and Kurt Stubbins.

As we gained knowledge throughout the course on how to work with steel, as soon as we began to bend steel we both knew there was something more about bending steel that we wanted to explore.

Feel free to ask us any questions or give us feedback!

Step 1: Project Brief - a Continuous Steel Stair

A Continuous Steel Stair is what we envision to be a modern minimalist industrial stair. Our design explores the possibility of having a continuous steel plate that is bent back and forth to support the treads of the stair. The railings are also cut from the same steel plate and they interlock with the continuous steel plate. For the most part the assembly of the different steel components depend purely on welding.

Step 2: Fabrication - Steel Components

We built a 1-to-1 prototype with standard 3' wide x 1' deep x 1" thick treads with a rise of 6".

For the prototype we built, this is the list of the components needed for assembly (as shown on the image above):

- 3.5' x 4.5' Steel Plate 3/16 thickness (to waterjet steel components).

Steel Components:

- Continuous Steel Plate with perforations indicative of the moments were bending shall occur (this plate supports the treads, the plate itself is attached to a stringer to gain structural rigidity).

- Railings Side Support & Railings Back Support

- L Brackets 2" x 6"

- Stringer 2" x 4"

- Nuts and bolts.

- Wood treads (not included in the image).

- Wood railings (not included in the image).

All of the steel components were cut with the the waterjet OMAX® 60120 at Autodesk Pier 9 in San Francisco.

Step 3: Steel Assembly

As shown in the image above the best way to begin assembling the steel components is by situating the L brackets on the stringer first.

The continuous steel plate is then bolted and welded to the L brackets and to the stringer as well.

The side railings interlock as puzzle pieces with the continuous plate on the side, after being interlocked they are welded together and the back railings are then welded to the back of the side railings and overlap with the puzzle joint between the continuous steel plate and the side railings, where all three are welded together to gain rigidity.

The next step is the placement of the wood treads and wood railings. The wood treads have four notches as shown in the exploded axon and they lock into two slots that are on the continuous plate, to the stringer and on the side of the railing to be flushed with the edge of the railing. The wood railing is bolted to the angle iron and the edges are rounded to ease the grip and feel of the railing.