Make a hardwood boring jig with a 1/2" plug bored to 3/8. Stick a dowel
in the hole and align the jig over the hole and clamp it in place. Pull
out the plug and drill with the jig as a guide. This type of jig is
easily made from shop scrap and should hang on the wall until the next
time you need it.
Years from now when you have passed on, people will look and wonder
what all those odd looking 'tools' are for. <G>
Bugs
"mike hide" <[email protected]> wrote in message
news:[email protected]...
> Here is a simple problem that I would like an answer to.
>
> I have drilled a 3/8" hole exactly where I want it only it should have
> been 1/2". How do I overbore it to 1/2" without changing its exact
> position. Needless to say it cannot be done on a drillpress and the
> material is wood......
>
Percision boring?
I had a 12th grade Physics instructor that could probably help you out. :)
One possibility:
Mark the center of a 3/8" dowel, insert dowel into existing hole, drill new
hole. A forstner bit might work best, depending on the original material.
Another possibility:
Make a drill guide jig on a drill press with a through hole 3/8" dia. and a
concentric 1/2" dia. hole drilled halfway through (like a deep counterbore) a
scrap piece of wood. Use the small hole and bit to locate the jig, then clamp it
to your workpiece. Then use the large hole to guide the 1/2" bit.
--
JeffB
remove no.spam. to email
mike hide wrote:
> Here is a simple problem that I would like an answer to.
>
> I have drilled a 3/8" hole exactly where I want it only it should have been
> 1/2". How do I overbore it to 1/2" without changing its exact position.
> Needless to say it cannot be done on a drillpress and the material is
> wood......
>
>
"John Eppley" <[email protected]> wrote in message
news:[email protected]...
> First: install a 3/8 drill in the drillpress. Do not start the
> motor.......
> Second: lower the drill into the existing hole and carefully clamp the
> wood to the drill base. You now have the exact center of the existing
> hole.
> Third: replace the 3/8 bit with the 1/2" bit.
>
> John
>
>
appreciate the post John, possibly you did not read my original post, I
cannot use the drill press only indirectly.
"mike hide" <[email protected]> wrote in message
news:[email protected]...
> Here is a simple problem that I would like an answer to.
>
> I have drilled a 3/8" hole exactly where I want it only it should have
> been 1/2". How do I overbore it to 1/2" without changing its exact
> position. Needless to say it cannot be done on a drillpress and the
> material is wood......
Regular twist bits are self centering. Experiment with using a regular 1/2"
bit and see if the results are acceptable.
Or use the method for drilling larger holes for door lock and handle sets.
Drill a hole with a 1/2" forstner bit through a 1x4 then center and clamp
the 1x4 over the 3/8" hole. Then use the clamped 1x4 and its hold to guide
the 1/2" bit.
JeffB <[email protected]> writes:
> One possibility:
> Mark the center of a 3/8" dowel, insert dowel into existing hole,
> drill new hole. A forstner bit might work best, depending on the
> original material.
I'd glue the dowel into the hole, let it dry, and then bore it out.
Good idea to mark th center first.
--
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"mike hide" <[email protected]> wrote in message
news:[email protected]...
> Here is a simple problem that I would like an answer to.
>
> I have drilled a 3/8" hole exactly where I want it only it should have
> been 1/2". How do I overbore it to 1/2" without changing its exact
> position. Needless to say it cannot be done on a drillpress and the
> material is wood......
Define precision? 1/32", .001", etc...
Someone else said to use a step drill - if you have one and depth doesn't
matter or it is a through hole, that might be the best answer. Insert the
3/8" portion and then turn the power on and drill out the 1/2" diameter...
--
Regards,
Joe Agro, Jr.
(800) 871-5022
(908) 542-0244
Automatic / Pneumatic Drills: http://www.AutoDrill.com
Multiple Spindle Drills: http://www.Multi-Drill.com
V8013-R
"mike hide" <[email protected]> wrote in message
news:[email protected]...
> Here is a simple problem that I would like an answer to.
>
> I have drilled a 3/8" hole exactly where I want it only it should have
> been 1/2". How do I overbore it to 1/2" without changing its exact
> position. Needless to say it cannot be done on a drillpress and the
> material is wood......
Take a 3/8 dowel and mark the exact center. If you don't feel you can do
this accuratly enough, turn one on a lathe and the center will already be
there for you. Cut to length, glue in hole, drill out with 1/2 inch when
dry.
Frank