As promised, boys and girls, here it is!!!
But please see my comment at the end of this post.
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.The micro adjustment for the router fence has been solved. Here.
I spent 2 beers thinking about this, and 2 more doing the work.
First I drilled a 1/4 hole in a piece of oak, (squared all around). Transferred the center line to the back of the fence. Installed a 1/4-20 insert into the back of the fence. (Epoxy to hold it solid).
The oak block has a 1/4-20 allthread going through it with 1/4 Stainless washers inside 1/4-20 elastic lock nuts. (All parts were "polished" on 400 grit to reduce drag.) I then made a fancy bloodwood knob just for sheets and giggles.
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Now that we have all that solved,(to my satisfaction), let's see why we are doing this in the first place. I am almost 70 years old. My eyes are not what they used to be. But I can still see a fine pencil mark (.003") in the front of my router fence. If I need to make a .003" adjustment, just watch the pencil mark when you tap it with a small mallet. A .003" adjustment on 1 end of your fence will give you about .0015" at the bit. We are working wood here. Not aligning a steam turbine in a nuclear power plant. (Done that!). If you need a device as has been described afor, mayhaps you are in the wrong business/hobby. But on the other hand you have four fingers and a thumb.