jim evans (in email@example.com) said:
| I always have to adjust by rotating the router body in the base.
| This is a very course adjustment making it difficult to get the cut
| depth set right.
| When I try to use the fine adjustment ring it doesn't seem to do
| anything at all -- it just turns and turns but the blade does not
| rise or lower. What I am doing wrong?
As DonkeyHody noted, the ring is only a scale. You _can_ do reasonably
accurate adjustments with it if you zero it to the bit. For straight
bits, it's fairly easy - upend the router and turn the body until the
bit is fully retracted, lay something flat across the base, turn the
body to raise the bit until it just barely touches the "something
flat", and tighten the adjustment clamp knob. With that done, rotate
the ring until its zero lines up with the line scribed on the body.
Now you're ready to loosen the clamp knob and rotate the router body
until the depth you want lines up with the scribed line. Now if you
cut a dado, it'll be within a gnat's whisker of the depth you wanted.
For extreme accuracy (I did this the last time I used my 690) I set
the router base-up on my bench, loosened the adjustment clamp knob
minimally, and retracted the router bit as above. Then I set a 1-2-3
block on the router base, positioned the face of my depth gauge on the
1-2-3 block, extended the gauge until it contacted the router
baseplate, and zeroed the depth gauge. Then I shifted the business end
of the depth gauge to ride the router bit as I rotated the router body
to raise the bit until the depth gauge indicated that I had the depth
setting I wanted to cut. At that point I tightened the router
adjustment clamp knob and re-checked. Sometimes the setting is
slightly spoiled (slop in the system) when I tighten the knob and when
that happens, I loosen the knob just enough to repeat the process. My
depth gauge is the digital type that'll read 1/1000ths with a +0.0005"
indicator and I normally work to those kinds of tolerances.
The factory-installed scale ring should let you repeatably set within
a 1/100" of any of the marked divisions; and if you have/develop a
good "eye", you should be able to do fairly well between divisions.
DeSoto, Iowa USA