modular cnc stair stringer
first implemented @ Northern mIchigan University 2023-24
In the world of theatre we often seek to fill our storage with reusable items to save both money & time. Stairs are a very common and necessary item that takes up a very large storage footprint. Inspired by flat pack furniture and the perfect repeatability of the cnc, I designed these modular stair stringers. Each stringer contains a number of 8” rise by 10-1/2” runs, positive stop framing locations, and modular extension pieces to overcome the 8’ length maximum of common sheet goods.
A full layout of the cnc stair stringers and the variety of achievable sizes to cover a variety of mezzanine heights.
3D drafted model from NMU's 2024 production of Anything Goes. This model utilizes a 4, 6, & 7 step stringer as well as the accompanying extension modules to achieve an 88" rise.
The 7 step or 56" rise stringer is our template stringer as we can most efficiently fill a 4x8 sheet with 4 stringers.
By laminating two stringers together we are able to achieve both the minimum necessary strength and rigidity to create the stair as well as offset seams to create longer length stringers.
Joinery for stringer elongation along the top of a stair stringer. Utilizing the framing joints used for stretcher boards between stringer laminations, this tab works as a positive stop to maintain our rise & run.
Joinery for stringer elongation along the bottom of a stair stringer. Utilizing the framing joints used for stretcher boards between stringer laminations this tab works as a positive stop to maintain our rise & run.