It's a math thing.

[Tom7227]

This one seems to be a math problem, geometry maybe.

I need to install a thing called a roto hinge. It is a device with two 3/4 inch round pieces of wood that are attached with a rivet in the center. You drill the door and the frame and you have hidden hinges.

The door is 1 1/2 thick oak made by laminating two pieces of 1X material.

How far from the door frame should the hinge be installed, and how much of it is the gap between the door and the frame? I think that if I put the hinge as far forward on the door as I can the measurements can be smaller.

I did it the first time having the center of the hinge 5/8 of an inch from the outside and front edges of the door and it didn't work. The way things are built how I have about a 1/4 inch gap to work with.

Any help is appreciated.

Thanks for your time.

Tom

[CAMAN]

Do you have a link or picture of the hinge?

[Tom7227]

It is the 3/4 one.

http://www.rockler.com/product.cfm?page=788

[Tom7227]

The opening is 15 5/16 wide, the door is 15 3/16 wide and 1 1/2 thick.

[hawgchaser]

Tom,

I'm trying to visualize your scenario. My answer may not even be to your question. Find a 1 1/2 in. template such as a washer and position it on the corner edges of a 2X? to find where/if the template center can accommodate the roll with your quarter inch gap and the size of your roto hinge. I suspect that the hinge may have to be so close to the front edge of the door, it may compromise the structural integrity of the wood. You may need to consider beveling/rounding the hinge edge of the door to allow for the roll. Location of hinge from top/side of door should be irrelevant. It's all about location from the face of the door. Hope I didn't attempt to answer the wrong question. Any chance of getting/making a smaller diameter roto hinge? The 3/4" diameter doesn't give you much "wiggle" room.

[Tom7227]

Thanks for the help. I am starting to think that I need to do something else. I had put it together once and it wouldn't rotate due to clearance on the hinge side. But also the door wasn't being held straight and rubbed on the non-hinge side. I think I am going to try and mortise in some regular hinges and call this a failed experiment with the roto hinges.

[LightningBG]

With such tight clearances, I think the front of the hinge side and the back of the (latch side?) would have to be beveled.

But, like you said, might just be best of try a different type of hinge if there is too much slop in the roto-hindge.

[Tom7227]

Here's a suggested solution but I'm not sure it is going to show up.

[McGurk]

Aaahhhhh, Pythagorus has chimed in. This is right, and your 1/4" clearance is going to be an issue more than likely. Your door is 1.5", so that puts the halfway mark at .75", which is also the distance from the edge he is proposing you use according to his 1.414 ratio (the square root of 2, which is also the ratio of the side to the hypotenuse). The further you go from the edge, the more apt your 1/4" clearance will work. Let me get some paper and see what I can find.

The other option is rounding off the edge of the door that is binding.

[CAMAN]

I think your best option with those hinges would be to either round over the door, or if you don't want that look, put a v-notch in the jam to allow the corners of the door to kick in.

[Surface Tension]

As is to close up the gap needed for clearance without altering the line you can plow out both sides. This would be along the lines of a V but not as noticeable.

Or move the hinge closer into the outside corner. That'll close up the gap required for the hinge side. A back bevel on the opposite side of door will give you clearance there.

The 1.5" thickness or the door isn't helping.

Look up "full inset adjustable door hinge". While you'll still be looking at reducing clearance because of the door thickness you'll at least will be able to adjust the door into the opening.

[hawgchaser]

Tom,

The drawing helps. I'm going to come back to the suggestion of making your own roto hinge...say from a piece of quarter inch steel rod with a washer as a spacer. The b+c leg of your triangle could be greatly reduced, since you could set the hinge so much closer to the door's face side. You could then use most of your 1/4" tolerance on the swing/roll side of the door and put a rather sharp (hidden) bevel on the opposite (inside) of the door. Also, the minimum "a" leg should be determined by moving your circle in the drawing to a point tangent to the bottom edge (in your drawing). That minimum distance for the door to clear will be the same as long as you keep the hinge "pin" the same distance from the door face.

[hawgchaser]

Quote:

The b+c leg of your triangle could be greatly reduced, since you could set the hinge so much closer to the door's face side.

That should have read, "The 'a' leg of your triangle could be greatly reduced, since you could set the hinge so much closer to the door's face side."

[jentz]

First thing is the door and jamb clearance is only 1/8 inch you need 1/4 inch, 1/8+ a smidgen each side.With that type hinge to keep a 1/8 edge clearance the door will need rounded edges.as the pivot point will not let a square edge clear.The pivot point should be set in 1 1/2 the diameter of the pin.These shouldn't be called hinges,they are pivot pins and without rounded edges your jamb/door clearance will have to be 1/2 the depth of the door.

I'd get some mortise in european style hidden hinges.Hinges not pivot pins