Building a Curved Central Cut String
This is an article that is not really about stair software but a visitor on my blog asked about making curved stairs. I have developed several techniques for different types of curved parts, cut strings, closed strings and handrails according to whether they are flattish, molded round etc.
Here’s the way I make a curved central cut string.
Note that although StairDesigner helped me set up the general lay out, the working drawings were drafted by opening the StairDesigner DXF files in Autocad.
Most of my curved strings are built using a technique I developed that I’ve called laminated layers. In fact to get the curved helical shape I glue together curved horizontal parts cut and calibrated from a flat board.
Here’s a photo of the cutting and calibrating the curved parts.

cutting layers on the band saw

calibrating on the spindle moulder
These parts are drilled and dowels used to reinforce the laminated assembly and stop slippage while gluing.

drilling layers for dowels
Note how I use the calibration template to precisely position the holes.
This photo shows how I glue the layers together using the dowels and template to align them.

Gluing the layers
For convenience I glue the parts together in blocks that are the height of one rise, and then assemble the blocks. This enables me to cut the helical under side with a saber saw.

Cutting the lower helical surface with sabre saw
I then assemble the blocks on a floor plan making sure everything is lined up with a laser plumb line.

Blocks assembled with laser plumb
Once the string assembled I glue laminates on the layers to give the string it’s finish. To glue the face laminates I use some special clamps.

Gluing face laminates

gluing laminates on the underside of the string
This stair goes up into a circular stair well, here’s the stair well assembled inthe workshop:

Circular stairwell
Here’s the curved string with the stair well assembled in the workshop:

string assembled with circular stairwell
And here’s the stair assembled with it’s center post and steps in the workshop:

Completed stair in workshop
And from underneath:

curved stair in workshop
Hope this has been of interest to you.
To see a few stairs that have been build using this technique visit my web site at :
If you would like more information on how to use this technique or on any other of my stair building techniques feel free to contact me.


Hey! I know this is kind of off topic but I was wondering if you knew where I could find a captcha plugin for my comment form? I’m using the same blog platform as yours and I’m having difficulty finding one? Thanks a lot!
Sorry Gerri I’m not very savey on WP plugins etc, you’ll have to do a search on Google.
all the best
Ness
We have a few designs you maybe interested in at http://www.stairbox.com/staircasegallery.html
Hi,
This is a well decorated stairs. Totally different from the traditional stair cases.