As you know, over the last couple of years wooden stairs greatly risen, so you have to find ways to save.
More recently, in Kostroma, it was possible to find a project half-pace stairs beech/oak in the area of 100 thousand, together with the work. Now the CBO is in the best case, will cost 120, and 140 oak kilorubley without installation. Wages have remained the same...
Was made a willful decision to collect and consider all by yourself. A few days of manual calculations, the eternal doubts and torments that did something wrong. And so I decided to use the Internet. Clicking on the first link I went to this website.
There are drawings and 3D model, all the calculations you can download, save, or forward directly from the manufacturer. Everything was very simple, and I spent a few days in vain.
As I collected the ladder, that's another story. I enclose a photo of the end result.
Thanks to the administrators!