Frank Ford posted on the Home Shop Machinist forum about his simple radius dresser:
Coincidentally, I just this week made a radius dresser for my tiny Sanford surface grinder. I just used materials I had on hand, and didn't make drawings. I'm at work now, but I'll post a photo or two here when I get home tonight.
Update, tonight -
Here it is "in situ," on the mag chuck:
I had this welded angle with a big hex nut stuck on, and I used it as the basic support. Just another item from the salvage bin. I bored the nut and angle to 1.125" to insert a couple of standard ball bearings that could accommodate a half inch shaft.
The "arm" of the dresser started out as a piece of heavy hot-rolled angle.
I turned and knurled the entire shaft from a piece of 1.5" 12L14 steel I had in the bin, and made a little flat spot to be able to lock it in place at exactly vertical so I could use the rig as a standard flat dresser as well as swinging it for radius forms. I did the graduations mostly because I could, and I can always use the practice, dontcha know.
Once I was finished, I spent some time with a height gauge and measured the center height accurately. As you can see, I wasn't so concerned with neatness as when I stamped the graduations on the knob. Oh, well, I never really expected to photograph this one. . .