Tool for enlarging deadbolt hole in door

[ymc226]

My house came with a custom solid wood extra thick 2 1/4 inch door which locks via a deadbolt. The deadbolt hole setback is the standard 2 3/8 inch but the round hole in the door is about 1 3/8 inches.

I want to get a new electronic smart Baldwin deadbolt but it requires a 2 3/8 inch hole. Is there a tool that can use the original smaller hole to center so I can enlarge the hole easily and accurately? I'd like to not take the door down as it is massively heavy and just enlarge it as is.

 

[nh_yota]

In the past I have used two hole saws nested together on the same arbor.

 

[billp603]

Clamp on some plywood to guide the pilot bit of a larger hole saw as seen here:

 

[Maui]

Bill, that is clever.

 

[Musicinabottle]

Bill, that is clever.

That's what I've always done.

 

[Whiskeymike]

In the past I have used two hole saws nested together on the same arbor.

I just happened to watch this yesterday and thought it might be useful regarding Yota's suggestion -

 

[Sticky Grips]

I've used the plywood guide method on concrete before.

For you, I'd suggest 1 of 2 things

1. Use a deadbolt drilling fixture, hole saw the correct size
2. Like Bill said above, double up on hole saws and use the smaller size as a centering tool.