door knob mounting hole

[charles cashion]

All of the door knobs in house are brand Dexter. The knobs are approaching 25 years old. They are all mounted in 1 7/8" holes.

Q1: Are there other door knob manufacturers that make 1 7/8" hardware? If the answer is NO, then I must enlarge my present holes to 2 1/8".

Q2: How can I hold a hole saw steady and centered while it is enlarging a 1 7/8" hole to 2 1/8" ? Thank you, Charles

[Limp Arbor]

You can do it this way or buy a jig at your hardware store

[charles cashion]

Thank you. That looks promising. Charles

[dadiOH]

Don't use a hole saw, use a router with a template, 2 1/8 hole in template.

- OR -

Don't use a template, use a relatively short router bit with a diameter greater than the shank...extend bit so it doesn't cut all the way through, use shank to guide on existing hole. Flip work over and repeat. Continue doing that until the enlarged side of hole is desired diameter then trim other side with a bit that has a cutting diameter same as the shank.

dadiOH

[Roger Shoaf]

There are 2 solutions to the problem.

First as it was suggested is to make or buy a jig to enlarge the holes to the 2 1/8 standard size.

The second way is to use Kwikset knobs that do not have the larger diameter bodies. Some of there models (The cheaper ones.) just have two posts. These will fit into the hole you have and you can if need be just use a wood rasp to widen the slots a bit if it is too snug.

[Stormin Mormon]

I know of none. Clamp on drill jig.

Many locksmiths have such a jig, and happy to do this for you. For a fee, of course.

[Don Young]

Ther are a couple other methods that have not been mentioned. You can make a tight fitting plug from a piece of 2"X2" or 2"X4" lumber (or a tree limb) and redrill with the larger saw. I once was able to put two hole saws on the same arbor with the smaller one sticking out farther for a guide. It didn't work great, but I got the job done.

Don Young

[David Nebenzahl]

On 5/29/2009 6:32 AM Limp Arbor spake thus:

'Zactly right. Jig, schmig: all you need is a piece of ply, Masonite, etc. I've done this and it works.

(It helps to have an alignment attachment on your drill to align 90° to the work. I got a cheap one years ago that I still use all the time. Available everywhere.)

[JIMMIE]

I have done it much the same way except I start with a hole saw that fits the exiting hole then drill in from opposite the side the plywood is clamped on just enough to get the pilot bit through the plywood. This gives me a reference hole for the larger hole saw.

Jimmie

[Doug Brown]

or consider something line this;