here is the plans I worked off of, deleted a bunch of measurements for clarity purposes.

I then drew the lower portion of the stairs onto a peice of plywood, with a few more radius's. The face of each stringer is a 96" radius, so I laid out a 108" radius a 120"radius on the left and right side, as well as a straight line in the center. As shown by the red lines on the auto cad drawing, they are 10" apart, I then had the measurements from the red line to the face of the bowed riser in front of it at the various radius's I drew and the center line, tapped some nails into the plywood at the marks and bent a 1/4"strip of wood on the nails and drew that arc. That's what the green marks are. I now have a full size pattern of the lower section of the stairs, I can now use this pattern for gluing up the treads, joint, rip the boards lay on the pattern until the tread covers the pattern of the tread on the plywood, repeat the process for each tread. next I cut the plywood pattern into the 4 riser pieces, went to the edge sander and sanded the down to the line, I did cut closer to the line than the picture shows. Then screwed another peice of plywood to the sanded peice and using the router made a duplicate peice, I now have 2 peices exactly the same.cut some blocks to the correct height, and made the riser forms for the 4 risers. .then to the big power matic belt sander where I sanded birch plywood down until it would easily bend to then forms, some went down to 5/8" and some down to 3/8". Spread construction adhesive on the form, and clamped the birch plywood to it.and here is how they turn out.till next time, how do you think I bent the riser material to this one??  Thanks to Stick and Lew for the help with the picture posting

Wow! Thanks for the insight into how these are made. You have an awesome shop!!

excellent...

thank you...

Forgot to mention, about 8 hours worth of time in the shop doing the work on the risers

and people think this kind of work just happens.  they have no idea the thought process, nor the unseen work that goes on out of view.  

 

fabulous.

Way above my pay-grade Kenny.

Awesome work & shop.

Thanks!