Crafftsman 315. depth rings

Hi R and welcome. Without reading the manual and seeing the router I am guessing that the white ring is for fine adjustment and the red ring is for major adjustments. You can post photos as long as they are in the hard drive of your computer.

My guess it's for zeroing out the depth. Somewhere on the body of the router is a reference line or triangle or something.

One way to use it, you can put in your bit, adjust the height until the bit just comes through the base, zero out the white ring, turn the red ring to adjust the height an exact amount, using the scale on the white ring.


In woodworking there is always more then one way to accomplish something.

I still have two of them in my shop. I haven't used them in many years. I upgraded a long time ago. BUT. I took a look at them just now, and I do remember those two dials. Of course you know that the red one is to lock the router at what ever depth you set it at by tightening it against the casing. I have never used the white dial for anything. I always thought it was suppose to be a setting for if you went from one depth to another, you could preset it for those two depths. But, since the depth of the cutter is determined by how much of the cutter is exposed. and since this depth would always be determined by how much of the shank you insert in to the router/ I always tightened it up and then measured to set the depth that I wanted to go. then adjusted the casing down or up to that spot, and tightened the red ring against it to hold it in place as you cut.
All of this it my meager attempt to say that I have no idea what the white ring is for.
There, I said it.
Think BOSCH !!
David

Terry nailed it. Zero the bit against your surface once you have it installed and then spin the zero on the white ring to the index mark on the router casing. The white ring will show you how much bit is exposed as you turn the red ring.