My son and I have come up with an idea that meets a specific
requirement but the method of fabricating the part is not
clear. So I'm soliciting suggestions.
Here's the evolution of the desired part - with the desired
part cross section shown at the end of the "context" text.
Three possible ways to fabricate the desired part, with
pros and cons of each method follow the "context".
CONTEXT
The Kid wants a birdseye maple top for the record cabinets we're
building for his LP albums collection. Looked into doing a solid
birdseye maple boards glue up for the top but that posed several
"challenges"
- getting 4 boards with the right distribution of
the birdseye patterns AND about the same "color"
- keeping the glued up top from cupping without
doing breadboard ends
- the birdseye pattern won't be on the edges of the top
or in the end grain
So we're looking into 1/4" birdseye ply top layer with
1/2" batlic birch ply below to make up the core of the
top. The "board match" problem is taken care of as is
the problem with cupping. However, getting the birds-
eye pattern on the edges of the top is still a problem
and the edges of the two ply layer top still need covering.
A solution is to frame the ply core with a solid birdseye
maple frame, perhaps biscuit joining 3/4" birdseye
maple with the figure on the outside faces to the edges
of the ply core. But biscuits would require the frame
to be 3/4" thick - too much without the birdseye
pattern on the edges adjacent to the birdseye ply top
face.
Another solution would rabbet/rebate the frame so
the ply core top would sit in the rabbet/rebate and
only 1/4" of the non-birdseye edge of the frame
would be visible from the top. But a 1/4" non
birdseye visible from the top "frame" around the
birdseye ply core would sitll be quite noticeable.
To minimize the visible amount of non-birdseye
pattern on the top edge of the "frame" the top
outside edge of the frame could be chamfered
to leave only 1/8" adjacent to the birdseye ply
top edges.
So here's the cross section of the "frame" we're
after. Note that the birdsey pattern needs to
be on the outside face.
1
--
8
+-+ ------
/ | ^ ^
+ | | |
| |-1/2" 3/4" |
| | | 1 "
| +---+ --- |
| | |
+------ + -------
|--3/4" -|
FABRICATION ALTERNATIVES
If the rabbet/rebate, which must be 1/2" wide
and 3/4+" tall, is done on a router table with
a fence, stability of the part being routed gets
a little weird because
- either only 1/4" is left on the"base" and the
bit is 3/4+" above the router table top.
+---------
|
3/4" | F
+------ + E
| | N
| +---+ C
| | B | E
| | I |
| | T |
| | |
-+-- +--- +------
- or if routed in this orientation, the increasing
overhang makes the part being routed unstable
the longer the overhang becomes.
+---------
|
|
+-----------+
| |
| +------- +
| | 3/4" |
| | Bit |
-+-- +----- --+-------
To get around the instability problem it might be
wiser to route the "rabbets/rebates" for two pieces
on the bottom of a single board, making them a little
wider than required, then ripping the desired part
from the dual rabbeted/rebated stock.
Rip here
F | |
E | V
N +-+ +--- -+ +-+
C | | | | | |
E | | | | | |
| +------+ +------+ |
| |
-- +------------------------+----
Rip here
F | |
E | V
N +-+ +----+
C | | | |
E | | | |
| +------+ |
| |
--+-------------+------
This, though a little more complicatedprocess,
and wastes a ittle of the precious birdseye maple,
seems to be the safest way of making the top's
frame up to the the top edge chamfering step
- which will be easy on the router table.
Comments? Suggestions? Questions?
charlie b
patriarch < wrote:
> Well, the first thing that came to mind was, when you can't easily conceal
> a change in material, then emphasize it, making it a design feature. A
> groove, a bead, or a change in wood color or species are means that came
> immediately to mind.
My suggestion was to go with a contrasting wood but since he's
building
it for himself and he wanted the birdseye figure on the faces of the
top's
"frame" my job is to figure out how to do it.
The idea of a bead on the top of the frame to act as a visual
transition
from the figured top "core" sounds interesting though I'm betting
he's
going to reject it as not KISS. But I'm going to pull out the LN
beading
tool and try it on a sample of locust. May be more difficult to do
on
birdseye maple since the grain runs every which way.
> Otherwise, I think that the construction option that rips apart the plowed
> dado is likely the safest method. I think I'd use a highly tuned bandsaw
> with a fence for this one. (I really ought to give mine a good going over.
> The fellow on TV always seems to be doing things that mine won't do. ;-))
>
Bandsawing a rabbet/rebate in a 26 inch long 1x3/4" piece of stock
is well beyond the 12 1/4" capacity of my LT16SEC : ). I did a test
of
the "route two dadoes in a piece of stock then rip out the desired
rabbeted part" and it worked. Of course, having a GRRRRIPPER
was handy - one "foot" in the dado on the fence side of the rip and
another in the other on the other side of the blade gave great
control
of the sample piece.
The real fun and games will come when the mitered cornered frame
is glued up with the top core in place. ANY errors in cutting
either
the core perfectly square or the frame either too long or too short
is going to show - AND the top has the same dimensions as the
cabinet
base - no overhang anywhere
Turns out that really "simple", really clean designs leave you
no where to hide little errors with overhangs or trim. I keep
discovering things that make me admire James Krenov's work
more and more.
> Thanks for keeping us up to date on this project. More signal. Less
> noise.
Dropped the Cow Magnets for the hidden lock mechanism and
ordered 1/4" diameter by 1 inch long cylinder earth magnets from
Lee Valley and have done a prototype of the new locking method.
Still waiting for The Kid to get couple of days to finish his cabinet
project - not including finishing time of course.
As for the signal to noise ratio - things seem to be settling down
a bit. Sure wish more folks would share the evolution of
some of their projects, with critical decision points, avenues
considered and tricks learned.
charlie b
Jack wrote:
>
> Attach the part to the top then run it through a table saw or chamfer the
> edge with a hand plane.
>
Not sure how to cut a rabbet/rebate into the inside of the table
top "frame" after it's attached to the top's core. Could you
elaborate?
charlie b
charlie b <[email protected]> wrote in
news:[email protected]:
> My son and I have come up with an idea that meets a specific
> requirement but the method of fabricating the part is not
> clear. So I'm soliciting suggestions.
>
<snippage>
>
> Comments? Suggestions? Questions?
>
> charlie b
>
Well, the first thing that came to mind was, when you can't easily conceal
a change in material, then emphasize it, making it a design feature. A
groove, a bead, or a change in wood color or species are means that came
immediately to mind.
Otherwise, I think that the construction option that rips apart the plowed
dado is likely the safest method. I think I'd use a highly tuned bandsaw
with a fence for this one. (I really ought to give mine a good going over.
The fellow on TV always seems to be doing things that mine won't do. ;-))
Thanks for keeping us up to date on this project. More signal. Less
noise.
Patriarch
Attach the part to the top then run it through a table saw or chamfer the
edge with a hand plane.
-Jack
"charlie b" <[email protected]> wrote in message
news:[email protected]...
> My son and I have come up with an idea that meets a specific
> requirement but the method of fabricating the part is not
> clear. So I'm soliciting suggestions.
>
> Here's the evolution of the desired part - with the desired
> part cross section shown at the end of the "context" text.
> Three possible ways to fabricate the desired part, with
> pros and cons of each method follow the "context".
>
> CONTEXT
> The Kid wants a birdseye maple top for the record cabinets we're
> building for his LP albums collection. Looked into doing a solid
> birdseye maple boards glue up for the top but that posed several
> "challenges"
> - getting 4 boards with the right distribution of
> the birdseye patterns AND about the same "color"
> - keeping the glued up top from cupping without
> doing breadboard ends
> - the birdseye pattern won't be on the edges of the top
> or in the end grain
>
> So we're looking into 1/4" birdseye ply top layer with
> 1/2" batlic birch ply below to make up the core of the
> top. The "board match" problem is taken care of as is
> the problem with cupping. However, getting the birds-
> eye pattern on the edges of the top is still a problem
> and the edges of the two ply layer top still need covering.
>
> A solution is to frame the ply core with a solid birdseye
> maple frame, perhaps biscuit joining 3/4" birdseye
> maple with the figure on the outside faces to the edges
> of the ply core. But biscuits would require the frame
> to be 3/4" thick - too much without the birdseye
> pattern on the edges adjacent to the birdseye ply top
> face.
>
> Another solution would rabbet/rebate the frame so
> the ply core top would sit in the rabbet/rebate and
> only 1/4" of the non-birdseye edge of the frame
> would be visible from the top. But a 1/4" non
> birdseye visible from the top "frame" around the
> birdseye ply core would sitll be quite noticeable.
>
> To minimize the visible amount of non-birdseye
> pattern on the top edge of the "frame" the top
> outside edge of the frame could be chamfered
> to leave only 1/8" adjacent to the birdseye ply
> top edges.
>
> So here's the cross section of the "frame" we're
> after. Note that the birdsey pattern needs to
> be on the outside face.
> 1
> --
> 8
> +-+ ------
> / | ^ ^
> + | | |
> | |-1/2" 3/4" |
> | | | 1 "
> | +---+ --- |
> | | |
> +------ + -------
>
> |--3/4" -|
>
>
> FABRICATION ALTERNATIVES
>
> If the rabbet/rebate, which must be 1/2" wide
> and 3/4+" tall, is done on a router table with
> a fence, stability of the part being routed gets
> a little weird because
> - either only 1/4" is left on the"base" and the
> bit is 3/4+" above the router table top.
> +---------
> |
> 3/4" | F
> +------ + E
> | | N
> | +---+ C
> | | B | E
> | | I |
> | | T |
> | | |
> -+-- +--- +------
>
> - or if routed in this orientation, the increasing
> overhang makes the part being routed unstable
> the longer the overhang becomes.
> +---------
> |
> |
> +-----------+
> | |
> | +------- +
> | | 3/4" |
> | | Bit |
> -+-- +----- --+-------
>
> To get around the instability problem it might be
> wiser to route the "rabbets/rebates" for two pieces
> on the bottom of a single board, making them a little
> wider than required, then ripping the desired part
> from the dual rabbeted/rebated stock.
>
> Rip here
> F | |
> E | V
> N +-+ +--- -+ +-+
> C | | | | | |
> E | | | | | |
> | +------+ +------+ |
> | |
> -- +------------------------+----
>
> Rip here
> F | |
> E | V
> N +-+ +----+
> C | | | |
> E | | | |
> | +------+ |
> | |
> --+-------------+------
>
> This, though a little more complicatedprocess,
> and wastes a ittle of the precious birdseye maple,
> seems to be the safest way of making the top's
> frame up to the the top edge chamfering step
> - which will be easy on the router table.
>
> Comments? Suggestions? Questions?
>
> charlie b