So I worked all day on this and got absolutely no further than yesterday. It's days like this that make me feel like I'm on a treadmill.
I want the cabinet doors to be covered in the fir tongue and groove that I stained so the wall looks all "of a piece" and the cabinet below the display area is barely visible. To that end I knew I'd need some sort of special hinge so I held off drilling the sides and assembling the boxes just in case the hinges I got were strange.
They were.
The guy at
NBH suggested I get the Salice CFA7P99 which would allow doors up to 40mm which would cover the 3/4" plywood interior and the 3/4" fir sheathing. So I buy 16 of them (four per door because they're going to be large doors) and go home to work it out.
The first problem was that the cups on the hinges aren't the industry standard 35mm but actually 40mm. So I had to go out and find a 40mm forstner's bit which wasn't easy. Of course the shaft was too large (3/8") for the Festool 1010 router I have but a call to a machine shop proved helpful because I learned that the shafts aren't hardened so I could fix this problem myself.
I knew my 3-jaw chuck wouldn't be accurate enough to cut the shaft down so I went for a collet. The runout was about .003" which on something spinning as fast as a router bit is way too much. I needed to be more accurate so that meant the 4-jaw chuck. It would also allow me to use a live center on the back of the shaft which, in addition to the better accuracy afforded by the 4-jaw would let me really be accurate. In order to hold the bit end I needed a shim to protect the teeth and soda cans are perfect shim stock. Refreshing too.
Here's a tip for centering your tool on the work.
Put a small ruler between your tool and the work and gently squeeze it to see if it stays vertical. If it tips back lower your cutter and if it tips forward raise it. This tool is on center which is how they cut best. It's a very quick way of getting it right and little tricks speed the work.
I probably should have indicated closer to the chuck but this dial indicator goes to tenths and I got this to within .0001" which is as good as I can get. The live center, the cone on a bearing in the back, will hold the work against any deflection and help make sure the part is accurate.
I took off 1mm a pass until I got close and then took my time to sneak up on 8mm.
This was as good as my day got today.
And just to be sure I took off the collet from the router to double check.
There you have it. A custom 40mm forstner's bit with a Festool compatible 8mm shaft.
The router base measured 39.90mm and I was going to rig this up on the rotary table but decided to just go the quick route and put a sanding drum from the dremmel in the drill press. It's only .1mm so it didn't take much to fix.
Then the hinges had to be drilled out for the 5mm cabinet screws I use...
Then finally I made a test fixture before deciding to drill all the boxes to the standard 37mm depth for the first set of holes that the hinges attach to. I mean, if the hinges are whacky I should test this...
I can't make hide nor hair of the Salice information despite scouring the net for hours. Every PDF from them lists out formula's for the hinges; D = (15+K) - H but there's always one or more undefined variable. It makes me crazy. The NBH guy had me take a photo of his catalog page which only specified 11mm spacing from the edge to the cup edge.
It's so close. If I push the hinge out a bit to a gap of 3-5mm I can just get the door edge to clear but the very corner of the test board on the door touches. I went back to look at different drawings from Salice and it appears that these hinges are for inset moulded doors or trim. Namely doors that aren't shaped like rectangles with almost no gap. I don't think they're going to work.
I think if I make the plywood interior door, the base that I'd affix the fir paneling to, a 1/2" board instead of the 3/4" I'm trying to use I could get the total thickness to just under the 1-1/4" that seems to be the outside limit of hinge capability.
Which really means that I spent my entire day performing a failed test.
Frustrating.
The upside is that other member of my family who
actually accomplishes things converted my old lumber into kindling for me. Yeah!
I've been trying to save all these excess boards but many of them were too long to be stored anywhere so I've been moving them around for a few years and they inevitably got wet, dirty and worthless. I threw in the towel and said chop them into kindling. I feel lighter now.
Tomorrow I'll return the hinges and start this process over...
Gregor