The problem: Starting with a sheet of plywood, I need to cut a full length piece with two perfectly straight and parallel edges.
Sounds easy right... that's what table saws are for? Ah, but there's no table saw available... The challenge is to do this with no power tools other than a cordless circular saw, a cordless drill, and a router. And just to make it interesting, the longest available straightedge that I trust is only 36".
Additional context... When I say "perfectly" straight, that begs questions about acceptable tolerances. Think tool-worthy tolerances rather than furniture or construction quality. The pieces I'm cutting will become references for other projects and/or pieces of jigs/tools.
The crazy solution I'm considering...
First, either trust a factory edge, or (my choice) make one edge straight as follows...
Second, make a cut, perfectly parallel to the reference edge...
The questions I'm asking... since ya'll have more router hours than I have router seconds...
Sounds easy right... that's what table saws are for? Ah, but there's no table saw available... The challenge is to do this with no power tools other than a cordless circular saw, a cordless drill, and a router. And just to make it interesting, the longest available straightedge that I trust is only 36".
Additional context... When I say "perfectly" straight, that begs questions about acceptable tolerances. Think tool-worthy tolerances rather than furniture or construction quality. The pieces I'm cutting will become references for other projects and/or pieces of jigs/tools.
The crazy solution I'm considering...
First, either trust a factory edge, or (my choice) make one edge straight as follows...
- When oriented right, my Bosch RA1054 edge guide looks remarkably like a jointer, so add a thin piece of laminate to the "outfeed" side of the guide using double stick tape.
- Put a 1/2" spiral bit in the router
- Align the router bit with the shimmed outfeed side
- Use the router like a jointer - making a few passes along the length of the plywood.
- Although the edge guide's "infeed" and "outfeed" fences are only 5" long each, we're starting with a factory edge, and a few passes "should" leave that edge as straight as possible within the tool constraints.
Second, make a cut, perfectly parallel to the reference edge...
- Remove the laminate shim (see step 1) from the edge guide
- Insert a 1/4" spiral bit (or perhaps 1/8"?)
- Set the edge guide to cut at the right width
- Then make a series of increasing depth cuts to cut off the piece - referencing from the previously straightened edge.
The questions I'm asking... since ya'll have more router hours than I have router seconds...
- Is there any reason this can't or shouldn't work? Any safety concerns?
- What changes would you make to the above procedure to improve safety, precision, or anything else?
- Is there an entirely different procedure you'd recommend? (Like buying a proper straightedge and using it as a saw guide instead of using a router for a saw.)
- What should I be asking that I'm not asking? (ie the things I don't know that I don't know.)