Flush Inset Door Hinging Options
I'll start by saying I am using Blum brand hinges. The same logic will apply to other brands but there will be product differences.
When hanging a door flush with a face frame there is a basic principle that needs to be met. That involves a term called "crank". Not the street drug either.
The hinge cup needs 18 mil worth of "crank" to throw the door in towards the center of the opening enough for the edge of the door to clear the frame and leave a gap, or "margin", between the the door and frame.
When dealing with concealed hinges most movement toward the opening is handled with the hardware choice. The type of hinge and the size of mounting plate. Some minor adjustments can be made with the bore distance but only a few mils worth.
For simplicity sake I'm going to use a 5 mil bore distance, the distance between the edge of the door and the hinge cup bore, on all set ups. And the two hinges I feel give the best results. They are these two, a "half crank" and a "full crank" hinge
The full crank has all 18 mil of crank built into it. The half crank has got 9 mil of crank.
One thing to mention about these two hinges is they do not have the same opening angle. The half crank has 120 degrees and the full crank has 107. I have not had anyone even notice the difference so I use them interchangeably.
If that was an issue with someone there is solutions for each of the following examples where we could use the half crank. You may be able to figure that out for yourself after I walk you through these scenarios.
I'll start with what may be the simplest. Blum makes this base plate exclusively for flush inset applications. The plate has the equivalent to a 9 mil plate height yet mounts directly to the back of the frame.
The main limitation is that it needs about 9/16" of clearance inside between a partition and the opening as I'm showing.
The simple jig we use to pilot the holes for the mounting screws incorporates the use of a "vix" bit. The self centering pilot bit used for piloting screws in butt hinges.
Its important to use some kind of jig so that those plates are all the same distance from the top and bottom of the opening. Then your doors can all be bored with a jig of some kind as well.
I find it best to pilot these holes before the frame is on the cabinet but we have a jig for those times we space out and forget.
So if that plate has 9 mil worth of crank we need to use the half crank hinge that has the other 9 mil built into it, getting our 18 mil needed. Again all bore distances are 5 mil.
Here is a typical set up. 2" frame with a 3/4" partition centered on the frame. Leaves a 5/8" reveal for the plate to mount easily.
This is pretty straight forward after you set yourself up with a working jig.
Now lets take a look at another fairly common situation.
1 1/2" frame part and the same 3/4" partition centered on the frame. As I'm showing here.
There is not enough room for the plate to mount on the frame as there is only 3/8" reveal, I need 9/16".
So we will use the partition to mount a euro style plate.
This is where I will use the full crank hinge. All 18 mil of crank is handled by the hinge so I need to create a mounting surface equal to a 0 mil plate.
This picture I have a 0 mil face frame plate clamped on the frame to indicate the proper relationship to the opening that we need. There is also a 9 mil euro style plate being held next to it.
Notice the arrows are pointing to the spot where the hinge mounts. They are very close to the same. Because the 3/8" reveal is very close to 9 mil.
So I have this jig to locate the pilot holes on the partition. It is the same as the previous jig as far as locating the plate the same distance from the corner of the opening.
Then when you find that you have 1/4" reveal from frame to opening you can do the same as above only use a 6 mil plate. Again 1/4" is very close to 6 mil.
And if you have a partition that is flush with the frame just use a 0 mil plate. Like this
So there is some reasoning behind the madness of these handy hinges. You just need the 18 mil crank and you can get any one of several ways.
In any of the above scenarios where I was creating a 0 mil plate equivalent there are options to create a 9 mil mounting surface so you could stick to one hinge with the same opening angle. Thats just not how I roll.
I hope this made sense and will clear up the mystery of these hinges. My goal is to get some of you to give this stuff a try. It can be fun, especially when outside is rather unpleasant.