I wanted to try making a wooden slide rule. I wrote a program to draw the rules and used a three ply construction to capture the slide.
My first attempt is not a complete success: the ticks are too dense at some points to be useful, the assembly is fiddly, and my first idea of just using registration pins and glue didn’t work out (I ended up using wood screws through the registration holes). There isn’t a cursor yet. Maybe a box-style construction would be better.
Thought a little about how to do the same thing. You went much further than I did and it turned out purty darn good.
Have a small collection of slide rules. Maybe a couple dozen. Not because I collect things, but because I enjoy fiddling with the past as much as the future.
I have one in a drawer someplace, including instructions on how to use it. Though I never learned to do anything but add. In 1995 when I took the architects licensing exam, it was still listed on the allowable tools to bring to the testing center.
I actually began with the intention of doing a circular sliderule, but switched over half way. I have a program to generate circular slides as well. There is an Instructable for an acrylic circular sliderule design that uses a three ply sandwich, no extra pivot necessary.
In case anyone wants to try this, here’s my latest revision, which changes some of the scale changeover points to reduce stroke density and adds a CI scale. It needs to be run through Inkscape or Illustrator to convert the text to paths before cutting. Ideas for better mounting strategies would be welcome.
Here’s my attempt at a circular version, intended for use as a medical dosage calculator. Three ply construction, but there is too much overlap on the center ply ridge, there is quite a lot of friction. Will have to try again.