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