I posted this question on another forum and will try here also.
I am getting ready to build the stairway into our loft. It has two full log stringers and I have them in place. The steps will be half log. I have built numerous conventional stairs, so calculations for rise and run are not an issue.
My plan is to get one step notched in, leveled both ways, and build from there. I have a metal jig in my head that would fasten to the top surface of a step that is already installed and also to the top surface of the next step to be installed. It would be adjustable vertically so that the step you are installing can rest on the log stringers for scribing. In order to maintain the proper rise, you would measure from the top of the step you are installing to the top of the step already installed with the jig holding everything in place. Then subtract that measurement from the desired rise and set the scriber to that dimension, then scribe for notching.
The stringers are about 14" dia and the steps are half log made from 11 - 12" logs. My original intent was to notch the stringers to make a pocket for the steps, but am wondering if there is any reason I can't notch the steps to fit the stringers instead. This would have the advantages of; not weakening the stringers, although I don't really think that is an issue, allowing some slight adjustment of rise by moving the step up or down the stringer a small amount, and if I screw up a notch, I only lose half of a 3' log, not an entire stringer.
Any comments? Thanks, Kent