Flutterby™! : Cabinet door prototype 2 2008-07-21 15:59:51.434774+00

Cabinet door prototype 2

2008-07-21 15:59:51.434774+00 by Dan Lyke 2 comments

The reception of my first mock-up for a cabinet door was instructive, so here's a first mock-up of the profiles we want to use now that we've got a router that'll swing those bits.

This is just a door, I think I'm going to do a frame shortly so that we can figure out how inset these things will be, and we need to settle on hinges and catches. Once again I had some alignment issues on the miters, I thought I had those licked but clearly not yet. On the other hand I think the straight edges do away with the "oozing caramel" thing, as does the sharper definition on the panel raising.

This hasn't been finished yet, it's got a coat of light shellac on it to seal the pores, but I'll be laying a coat of pore filler in the mahogany, and we're still trying to figure out if we're going to dye the maple, or just let it age into its orange color naturally. Maybe we'll just help it along with an oil based polyurethane, which has a slight yellow-ish tint.

The miter joints look much improved. As you have noted, miters can be very difficult to set correctly. Two or three thousandths is very visible. I worked in a picture framing shop for a couple of months when I was a student. They used a chopper -- two accurately machine blades bolted to a very heavy block which formed a very accurate 90 degree angle. This would cut both sides of the miter with two chops -- one coarse to remove most of the material, and one fine for the final cut. There were still problems with some of the joints. This was the result of pre-existing twist and/or warping in the wood, or changes that result from the release of tension in the wood when it was cut by the guillotine.

One way to help miter fits is to cut a compound angle 45 degrees at 89 and 91 degrees on each site of the joint. With the longer fit at the top. When you clamp them together there is a slight crush at the top, which can give you an additional couple of thousandths of closure.

I assume that you milled the profile for the rails and stiles -- how did you do it?

How do you like the new PC 7518 that you added with the router lift? I am currently using a Bosch 1613 without a lift, but am contemplating getting a heavy duty router just for my table. I use a setup block to estimate bit height, then fine tune it by means of a differential reading on a digital caliper. How close can you set the height with the Jessem lift?

For the miters, I still need to do a bit of tweaking with my fence. I'm close, but not exactly there. These are just a touch narrow, I've got a line scribed on my table top to align the fence to that I'm pretty sure is good to the width of the line (a ballpoint pen) at 2' or so, but it's offset the pen width from the fence, which I eyeballed from close to the rotation axis to far away this time. What I should have done is used the calipers to measure from the holes in the MDF table top again. Did that for a picture frame and got very very close.

I think I'm going to get a sheet of apple ply or baltic birch, cut a bunch of miters iteratively 'til I get dead-nuts on, then cut a triangle out of this stuff and glue a side on to it so I've got something I can slap up against my rail and press the fence to. Come to think of it, HDPE might be the right material for that, or acrylic.

The other thing that's helped is pouring cyanoacrylate in the joint before sanding (and remembering to leave the vacuum hose off the sander at first).

On milling the rails and stiles, the profile is an almost elliptical table edge bit. I cut the inside round after cutting the miters, but waited 'til after assembly to cut the outside rounds. That way I had the rest of the frame to keep the piece from rotating. The panel is set in a rabbet right now, a direction I'm headed because I'd like to hold it in with screw blocks from the back so that I can take the panel out for cleaning and re-finishing, I just cut the rabbet with a bearing bit after the frame was glued up.

Bit height on this was slapped up pretty ad-hoc, for the most part it was match the outside of the bit to the table surface; put a block on the table top, crank it up 'til the shallow end of the bit hits it. The Jessem lift is 1/16" per rotation of the crank, and I feel no backlash, so in theory it should be easy to get 1/256". I'm coming from a cheap Craftsman ½HP router, so anything's an improvement, but being able to crank the 7518 down to 11,000RPM is awesome for those big bits, even for cutting the rabbets running slower helped tear-out immensely, and I can't tell if it's better bearings or what, but I'm finding it a lot easier to feed my stock.

The only wackiness is that it sounds like the router goes up to full speed when it's first turned on and then slows down to its set speed.