Hi,

Say I want to cut a hole in a table to fit an irregular but mostly
cylindrical piece. The pattern (the cylinder) is a negative pattern;
it's the shape of the material to be removed.

The only approach I can come up with is to fix some template material
on top of the cylinder, and use a flush cut router bit with a bottom
guide to cut a positive template the size of the cylinder plus the
diameter of the bit.

Then, I use the positive template with a template following bushing to
cut the hole in the table. The hole in the table will be smaller than
the hole in the positive template by the bushing radius - the bit radius.

For example, if I'm using a 3/4" diameter bit (3/8" radius) and a 2 1/4"
bushing, 2 1/4" = 9/4" diameter, 9/8" radius.

3/4" = 6/8" = 9/8" - 3/8"

Is this the best way? Assume that the "cylinder" is not regular, so I
want to trace it and not just measure the diameter and cut a circle of
that size. And, tracing around the cylinder and then carefully
cutting inside the line doesn't work because I'm clumsy and impatient.

I'm really looking for a general procedure for cutting an opening the
same size and shape as an object, using a router. Seems like there
should be a better way to do this, but I can't think of it.

Thanks,

--- Chip

Chip Buchholtz wrote:

| I'm really looking for a general procedure for cutting an opening
| the same size and shape as an object, using a router. Seems like
| there should be a better way to do this, but I can't think of it.

We had a thread on this not so long ago. Try the link in my sig.

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/GBRecess.html

Morris Dovey wrote:
: Chip Buchholtz wrote:

: | I'm really looking for a general procedure for cutting an opening
: | the same size and shape as an object, using a router. Seems like
: | there should be a better way to do this, but I can't think of it.

: We had a thread on this not so long ago. Try the link in my sig.

Thanks - I knew that that was one way of doing it, I just couldn't
get myself to believe that there wasn't an easier way. I guess you
are saying that using an intermediate template and different size
bushings is the only way to go.

Thanks,

--- Chip

Chip Buchholtz wrote:
| Morris Dovey wrote:
|| Chip Buchholtz wrote:
|
||| I'm really looking for a general procedure for cutting an opening
||| the same size and shape as an object, using a router. Seems like
||| there should be a better way to do this, but I can't think of it.
|
|| We had a thread on this not so long ago. Try the link in my sig.
|
| Thanks - I knew that that was one way of doing it, I just couldn't
| get myself to believe that there wasn't an easier way. I guess you
| are saying that using an intermediate template and different size
| bushings is the only way to go.

Not at all - but you /did/ ask for a general procedure.

If I were doing this, I'd take a photo of the object, import the image
into my CAD package, trace the shape I wanted, export the tracing as a
DXF, and pass the DXF to my CNC router control program for cutting.

There's /always/ more than one way to skin a cat...

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/

"Chip Buchholtz" wrote in message
...
Hi,

Say I want to cut a hole in a table to fit an irregular but mostly
cylindrical piece. The pattern (the cylinder) is a negative pattern;
it's the shape of the material to be removed.

snip

http://www.woodcraft.com/family.aspx?FamilyID=1391

This solid brass router inlay kit works really good for me. Norm used it on
his show one time. I think I may have to make some butterflies to join a
table top like Nakashima featured on his work. If I do, I will certainly use
the inlay kit.

Morris Dovey wrote:

: If I were doing this, I'd take a photo of the object, import the image
: into my CAD package, trace the shape I wanted, export the tracing as a
: DXF, and pass the DXF to my CNC router control program for cutting.

Good point - actually, a very useful suggestion.

Where I work they have a CNC laser um, "milling machine" is the best
description I can come up with. It's in a different department, but
I'm told that they don't mind doing little projects for people.

If I go that route, I'll have to decide whether I just want to use CNC
to make the template, or have the CNC machine make the final cut.

Thanks!

--- Chip

dadiOH wrote:

| Smarty pants

Not intentionally - I've just given up on trying to hide how lazy I
really am. :-D

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/

Morris Dovey wrote:
Chip Buchholtz wrote:
Morris Dovey wrote:
Chip Buchholtz wrote:

I'm really looking for a general procedure for cutting an opening
the same size and shape as an object, using a router. Seems like
there should be a better way to do this, but I can't think of it.

We had a thread on this not so long ago. Try the link in my sig.

Thanks - I knew that that was one way of doing it, I just
couldn't get myself to believe that there wasn't an easier way. I
guess you are saying that using an intermediate template and
different size bushings is the only way to go.

Not at all - but you /did/ ask for a general procedure.

If I were doing this, I'd take a photo of the object, import the
image into my CAD package, trace the shape I wanted, export the
tracing as a DXF, and pass the DXF to my CNC router control program
for cutting.

Smarty pants

--

dadiOH
____________________________

dadiOH's dandies v3.06...
....a help file of info about MP3s, recording from
LP/cassette and tips & tricks on this and that.
Get it at http://mysite.verizon.net/xico

On Sat, 18 Aug 2007 02:45:47 +0000 (UTC), "Chip Buchholtz"
wrote:

Morris Dovey wrote:

: If I were doing this, I'd take a photo of the object, import the image
: into my CAD package, trace the shape I wanted, export the tracing as a
: DXF, and pass the DXF to my CNC router control program for cutting.

Good point - actually, a very useful suggestion.
...

Well, it's one alternative, but for those of us who neither have nor
have access to numerically controlled tools in our
basement/garage/etc. workshops, I'm not too sure just how useful the
suggestion is.

Tom Veatch
Wichita, KS
USA

Tom Veatch wrote:

| Well, it's one alternative, but for those of us who neither have nor
| have access to numerically controlled tools in our
| basement/garage/etc. workshops, I'm not too sure just how useful the
| suggestion is.

It wasn't actually a suggestion. My intended contribution was in the
form of a link to a web page with some very simple geometry/algebra
shwing how to select guide bushing/router bit sizes so the job can be
done by anyone with a hand-held router with a base plate that allows
using bushings.

In case you missed it, I've repeated it below. If it seems not useful,
there's an e-mail link at the bottom of the page for improvement
suggestions.

I only mentioned the CNC approach when asked if the guide
bushing/template method was the only way the job could be done and if
there wasn't an easier way. It was not intended to cause rancor - only
to illustrate that other (and easier) methods existed. That Chip has
access to CNC tooling at work is a happy coincidence.

Sorry if I rubbed your fur the wrong way.

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/GBRecess.html

"Morris Dovey" wrote in message
...
Tom Veatch wrote:

| Well, it's one alternative, but for those of us who neither have nor
| have access to numerically controlled tools in our
| basement/garage/etc. workshops, I'm not too sure just how useful the
| suggestion is.

It wasn't actually a suggestion. My intended contribution was in the
form of a link to a web page with some very simple geometry/algebra
shwing how to select guide bushing/router bit sizes so the job can be
done by anyone with a hand-held router with a base plate that allows
using bushings.

In case you missed it, I've repeated it below. If it seems not useful,
there's an e-mail link at the bottom of the page for improvement
suggestions.

I only mentioned the CNC approach when asked if the guide
bushing/template method was the only way the job could be done and if
there wasn't an easier way. It was not intended to cause rancor - only
to illustrate that other (and easier) methods existed. That Chip has
access to CNC tooling at work is a happy coincidence.

Sorry if I rubbed your fur the wrong way.

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/GBRecess.html


You know what Morris, You didn't offend me at all. I think you do a lot of
really nice work. If I had a reason for a CNC set up I would do it in a
heart beat.

If the op will look at the router inlay kit and determine how it works; with
a set of guides (Delta) and different diameter straight
router bits, he can come up with what he's looking for. I can visualize
making a bushing that will do exactly what the kit does.

I bought the kit when I was building a bed for my daughter and I had ruined
a piece of wood that cost more than the kit did and I had several hours in
the piece. I was able to make a dutchman with the inlay kit and the repair
is barely visible. I put it on the back side of the bed and saved myself
money, time and I have a new tool in my collection. :-)

Tom Veatch wrote:

| I'd be tickled pink to have a CNC
| presence in my shop and am eat up with envy for those who do.

No reason you can't have one in your shop - there are plans and parts
available on the web so you can build/assemble your own. They aren't
particularly cheap, but you can buy a controller kit and steppers for
less than the price of a Festool Domino - and control software can be
downloaded for free. You already have the computer.

As with any new tool, it takes a while to learn to use it well - and
if you'd like a coach, you have a volunteer.

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/

On Sun, 19 Aug 2007 03:19:00 -0500, "Morris Dovey"
wrote:
....
As with any new tool, it takes a while to learn to use it well - and
if you'd like a coach, you have a volunteer.

Thanks, Morris. I appreciate the offer and if I ever get some of the
higher priority roundtoits and honeydos worked off I may well take you
up on it.

I was following the building of a CNC router by the author of the DVD
magazine "Woodworking at Home", but either don't have all the episodes
or he didn't finish before I let my subscription expire. It's
something I want to do, but higher priority tasks are interfering.

Tom Veatch
Wichita, KS
USA