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.

how to make curved stairs
cutting layers on the band saw
calibrating ont he spindle moulder
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
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
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
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
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.

stair design
Gluing face laminates
gluing laminates on the underside of the string
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
Circular stairwell

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

string assembled with circular stairwell
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
Completed stair in workshop

And from underneath:

curved stair in workshop
curved stair in workshop

Here’s the stair installed in the clients bedroom.

finished-stair
Curved Stair built using horizontal laminates

Please register here then post your own stair project on our forum for expert help and support

As well as buying StairDesigner, we also have an option where you can sign up for Premium Support and use the software without buying. Click here for more information on our StairFile service to do that.

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