I was replacing some old-style doorknobs with newer ones, and I ran into a problem. The old knobs went through a hole about 1/2 in. dia., but the new knobs needed a 2-3/8-in.-dia. hole. I needed to find a way to use my hole saw without it wandering all over the place. I decided to wrap masking tape around the bit of the hole saw until it was just slightly smaller than the hole in the door. My solution worked great.
—John Swope, Harrisburg, PA
Edited by Charles Miller
From Fine Homebuilding #240
View Comments
Seems like there've been half a dozen different Tips about this kind of problem recently, which is to say, it's a real problem sometimes. Maybe we can put our collective heads together and find a definitive solution.
I'd say there are 2 problems, keeping the holesaw from flopping around, and locating the new hole accurately- in the tip above, Swope was lucky both locksets had the same setback.
A gadget solution: Starrett KA19 OOPS hole enlargement arbor
https://www.starrett.com/metrology/product-detail/KA19
https://www.starrett.com/category/240204#currentPage=1&displayMode=grid&itemsPerPage=12&sortBy=wp/asc
https://www.leevalley.com/en-us/shop/tools/power-tool-accessories/hole-cutters/52518-oops-arbor [free shipping]
that's a sweet solution . . . I would cut the new hole first in a scrap of plywood, then clamp that scrap to the door in the right position. The edges of the new hole will guide the saw to cut in the right place on the door.
This is my go-to solution for this problem.
use a holesaw to cut 1/2" plugs out of scrap. Wind enough plugs on to the center drill of the 2-3/8" holesaw until they project just above the saw teeth. You now have an arbor that centers the new hole concentric with the original