Hi all,
I'm a novice (though not a newbie), and I'm struggling to find a solution to what ought to be a pretty simple problem. Here's the deal:
I'm creating a box that will have multiple dividers in it. Rather than gluing the dividers to the bottom and sides of the box, I'd prefer that they be slightly mortised into the sides of the box. Not a lot, maybe an eighth-inch in to each wall (the walls will be about 7/16" thick). This way the dividers aren't going anywhere at all, and to my mind this is better than butting the dividers up against the wall and hoping there's enough glue surface to hold 'em. Ideally I'd like the dividers to be 5/16" thick. 1/4" would be okay too but 5/16" seems about right for the proportions.
Now, the dividers aren't as tall as the box walls. So the mortise has to go -partly- up the side of each box wall - we're not talking about a simple dado. The rub is, I can't figure out a good (read: relatively painless) way to accurately put the mortises in. The two basic requirements are that they all have to be the same height, and from one wall to the opposite wall the mortises have to be a perfect mirror image, otherwise the dividers won't line up. I've done this once successfully using a router table, 5/16" straight bit and very, very, very careful measuring, marking, remeasuring, copious use of stop blocks, pausing to pray, etc. But this took me several hours (!) to install two shallow mortises - enough for one single divider. This can't be the most efficient solution.
I already have the problem of rounded mortise edges solved - simply using a roundover bit on both sides of the dividers themselves makes the profile a good fit for the rounded end of the mortise. No problem there.
But - for my current project I need a lot of dividers, so I'm trying to figure out how this can be done efficiently. I'm sure there's a slap-your-forhead-simple way, but I haven't come across it yet. Here's what I -have- thought of:
Route by hand using a straight edge as a guide. This is okay as far as it goes, but my router is pretty bulky (DeWalt 621) and not terribly easy to use this way. Plus, you'd have to change your setup for each mortise, so I'm not sure it would be all that much faster than the method I described above. It also introduces a lot of potential for each mortise being ever so slightly off. That's enough to convince me it's not a good approach.
Now, a template should be a good way to go, since it's repeatable and if it were routed all the way through it could be flipped over to create the reverse image - thereby making an instant setup for the opposite wall. But:
Template on a router table. This seemed at first to be a viable approach, but then I realized that it would be impossible to route a shallow mortise from below, using a guide. If I were routing all the way through the piece, this would work. But it's physically impossible to route a shallow mortise this way.
Template on a bench, router on top. Okay, this makes sense at first too. But this would require a templating bit 5/16" in diameter, and so far as I can tell there's no such thing (templating bit meaning the guide bearing is at the shank end). Half inch, no problem. Bigger than half inch, no problem. Less than half inch, forget it (from what I can find, anyway).
Now then, all of this has lead me to conclude that using some sort of bushing setup on the router is the only way to do this. Fine, I can go get some bushings (assuming anyone makes some that can adapt to the
621...?) and I imagine this would work, using the through template idea mentioned above.But before I go do that, is there some flaw in my thinking? Where's the slap-my-forehead-simple solution? I can't be the only person who wants to make boxes with accurate mortised dividers....
PQ