Carlpenter
Member
Eric The Viking":241di3ju said:
Fixing to a door lining made from 32mm thick timber, screwed to a brick wall (exterior, the next room is an extension).
Bookcase door
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Fixing to a door lining made from 32mm thick timber, screwed to a brick wall (exterior, the next room is an extension).
Carlpenter
Member
nev":1f3negpl said:
Yes that’s a point. Need to maximise the opening though, as the client is a big lad.
I intend to use a pivot system in any case.
i think what you are missing here is the physics of what you are attempting to do.
Assuming your load is 400kg and is evenly distributed then the centre of gravity is 0.7m (1/2 x 1.4m) from the hinge edge. Its not just the weight you need to worry about, it's the moment exerted on the hinge/pivot. This would be 400kg x 0.7m. This would be acting not just as a mass to be supported but also to pull the top corner of the hinge side directly away from the wall.
No matter what hinge/pivot mechanism you use, you are going to need make sure that whatever it is fixed to is sufficient, and I can't imagine a std 32mm door lining is going to work.
You can reduce this moment in two ways. Reduce the mass. Or reduce the distance from the CofG to the hinge. A central pivot would be a good way of both reducing the distance as well as transferring the load down into the floor (presumably to something structurally solid).
Whatever you do to strengthen this edge and whatever hinge and pivot you use I would look to counter this moment by supporting much of the mass on a jockey wheel or other castor arrangement on the lower corner furthest from the hinged edge.
Assuming your load is 400kg and is evenly distributed then the centre of gravity is 0.7m (1/2 x 1.4m) from the hinge edge. Its not just the weight you need to worry about, it's the moment exerted on the hinge/pivot. This would be 400kg x 0.7m. This would be acting not just as a mass to be supported but also to pull the top corner of the hinge side directly away from the wall.
No matter what hinge/pivot mechanism you use, you are going to need make sure that whatever it is fixed to is sufficient, and I can't imagine a std 32mm door lining is going to work.
You can reduce this moment in two ways. Reduce the mass. Or reduce the distance from the CofG to the hinge. A central pivot would be a good way of both reducing the distance as well as transferring the load down into the floor (presumably to something structurally solid).
Whatever you do to strengthen this edge and whatever hinge and pivot you use I would look to counter this moment by supporting much of the mass on a jockey wheel or other castor arrangement on the lower corner furthest from the hinged edge.
LancsRick
Established Member
Before you get into the design of the thing itself I'd get yourself comfy on your pivot and the required castors and floor support.
For the pivot you not only need one that will take this force but also a way of mounting it, this will need to be straight into solid masonry I'd suggest.
For the castors, I assume you're going on to a hard floor so your options would be roller castors or normal ones under a false front skirt. I'd go for normal ones as they will be less sensitive to getting dirt trapped in them.
Those are the two eat urea you have to design around so take it from there.
As a passing suggestion, do you need the equivalent of a double door or will one half fixed and one half opening suit you? Becomes a far far easier piece of design then!
For the pivot you not only need one that will take this force but also a way of mounting it, this will need to be straight into solid masonry I'd suggest.
For the castors, I assume you're going on to a hard floor so your options would be roller castors or normal ones under a false front skirt. I'd go for normal ones as they will be less sensitive to getting dirt trapped in them.
Those are the two eat urea you have to design around so take it from there.
As a passing suggestion, do you need the equivalent of a double door or will one half fixed and one half opening suit you? Becomes a far far easier piece of design then!
Perhaps make it a pair of doors (both swung) on concealed tectus hinges. There are certainly hinges suitable for the weight but ideally you’re going to need to lighten and strengthen the doors by replacing timber with metal framework with thin timber cladding to make it look like wood (if that’s the desired finish). To overcome it self destructing due to the loads involved. I’d strongly recommend the castors to support the load vertically straight onto the floor as this will significantly reduce the load on the hinges, however the floor really needs to be flat to avoid issues with binding or they will need to be suitably spring loaded to deal with an uneven floor. Bookcase doors are typically much more successful when they swing into the hidden room as it allows all the gaps to be concealed behind architrave etc. Either way your clear opening is going to be restricted heavily by the depth of the door. On a side note, However much you think this is going to cost, double it then add 50%
I suspect this is a concealed room entry. If so, it would be simpler to make the whole damn thing slide sideways along the wall.
But if you are asking this question, you really should pass this VERY difficult job up.
But if you are asking this question, you really should pass this VERY difficult job up.
MattRoberts
Established Member
Why not just have the bookcase sitting on 4 appropriate load bearing casters? You can use any hinges you want then, as they're just there to anchor it to the wall
A couple of people have suggested using castors to take some of the weight. The problem there is that castors running on a fixed path will eventually wear a track on the floor. Unsightly at best and maybe a serious problem if the idea is to hide a door - to a panic room for example.
I saw an article years ago about testing such a door backed with a panel having a thin steel plate sandwiched between two pieces of plywood. The steel was glued to the plywood and there were bolts through the full thickness of the panel. I don't remember specifics but the difference in strength & distortion compared to a similarly-sized pure plywood panel was considerable. The steel was thin enough that on its own it would be worthless but sandwiched between the plywood so it couldn't buckle it helped a lot. Still needs some serious hinges though.
I saw an article years ago about testing such a door backed with a panel having a thin steel plate sandwiched between two pieces of plywood. The steel was glued to the plywood and there were bolts through the full thickness of the panel. I don't remember specifics but the difference in strength & distortion compared to a similarly-sized pure plywood panel was considerable. The steel was thin enough that on its own it would be worthless but sandwiched between the plywood so it couldn't buckle it helped a lot. Still needs some serious hinges though.
I cant see any other reason for this than to hide a room, so a sliding unit can be very easily supported from the inside, where visibility is irrelevant. think of an airplane door type of thing.
Pull it out, slide it along. No marks showing on outside walls or floors.
That way it could even be powered, making access very quick.
Pull it out, slide it along. No marks showing on outside walls or floors.
That way it could even be powered, making access very quick.
Sheffield Tony
Ghost of the disenchanted
Just4Fun":33wavzty said:
Only a problem if you are of very nervous disposition :lol:
Yeah, not a problem for me - I can barely lock my house - but I believe some people do have such things as hidden rooms. Could be fun for a kid as well as a placebo for Mr Nervous I guess.Sheffield Tony":1pefyiin said:
My wife tells me that she once rented an apartment for a year and it wasn't until she was cleaning prior to moving out that she found an additional room she did not know about previously. Perhaps that says more about her than about the apartment but we'll gloss over that.
Sheffield Tony
Ghost of the disenchanted
Just4Fun":3080jayh said:
I was not so much thinking of being nervous enough to want a panic room, but being panicky enough to to wear tracks in the floor by using it so often !
But as a kid's den - a secret room, how exciting.
