How to move a bookcase using upper rails

I want to build a set of 3 bookcases that slide to a corner to reveal a study area. For that I though about using a metal framework to support all bookcases from the top using two rails.
So when needed, I would just push the bookcases along the rail path. The big problem, is that it has a change in direction of movement (left-right to front-back, see ilustration from the top), and I have NO IDEA on how to implement supports for the bookcase that allow a direction change like that.

Do you have any ideas on rails and supports/hangers that allows for direction change.

Picture of How to move a bookcase using upper rails
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elton293 years ago
That is seem quite hard.Many people at Finland country use by a library furniture for their home in http://www.ktinterior.fi/ because sometimes it is really hard to make a book shelf it is better to buy a new one in a very cheap price.
superman7864 years ago
Yes, but you'd need some "sweep" in the corner, like a big vehicle turning.www.funique.co.uk
caitlinsdad4 years ago
Bookshelves can become quite heavy. Unless you know how to engineer your rail system to be strong enough and know how to properly secure it to the ceiling, you are really better off in mounting casters to your bookshelves if they are on the floor. But if these are overhead cabinet style shelves, what you need to do is to have a hanging monorail type system where the rail flanges on are enclosing and supporting T shape peg (post with round disk on top) attached to the hanging bookcase. Or invert the rail design with an inverted T track on the ceiling with riding wheel brackets attached to the bookcase. You might want to curve the rails in the corner. Good luck.
luiz_borges (author)  caitlinsdad4 years ago
These would be 3 bookcases about 3 ft wide and 7 ft high, I know it will get quite heavy and for that I thought about building a steel frame to support it (see image). I guess that frame will be able to handle the load quite nicely.

From a physics point of view, both an bottom rail and an upper rail will need the same amount of work to move, the upper rail advantage is that it will be dirty free (no dust or debris getting in the way) and no rail tracks on the floor (which is good from a funcionality and a aesthetic point of view).

I thought about the curved design but I don't really know if it will work since the support in the bookcase will have to move and that might be problematic and cause all sorts of trouble.

The image attached show how the bookcases will move:
- The left one will move 2 steps to the back (the red area);
- The center one will move 1 step to the left and 1 to the back (the orange area);
- The right one will move 2 steps to the left (the green one);

The central one is problematic one.
- The left one will move 2 steps to the back (the red area);
A simple forward and back slide.

- The center one will move 1 step to the left and 1 to the back (the orange area);
Obvious solution is vertical axle shaft in the upper left corner of the orange footprint
hinged at the ceiling and floor that will swing into slot stack #2.

- The right one will move 2 steps to the left (the green one);
A simple left and right slide.

.. -.-. . -. --.
lemonie4 years ago
This is a "compact shelving" type of bookcase.
You could have a "dock" in the corner, i.e. a platform which the shelves run on and off in one direction, but slide on top of in the other. You'd need two linear tracks on different levels.

I don't know whether compact shelving is manufactured this way, but the OP for this application could use a single track layer with a relatively small radius at the corner, and free casters into the rails. The casters will follow the radius track and turn automatically as the corner is reached.
Yes, but you'd need some "sweep" in the corner, like a big vehicle turning.

Um. You were right about this, given that I wrote about putting casters on all four corners. That's wrong. The design I had in mind uses four casters (or ball transfers) on the floor, but only two, on diagonal corners at the top. Those two can then follow the tracks drawn by the OP, if they can pivot themselves at the corner.
No you don't, at least not with the diagram the OP provided. He wants the shelves to maintain the same orientation in all positions (think "parallel transport" with geodesics). So it slides down to the corner. As it gets to the corner, the casters up on top pivot around their mounting posts as they follow the curved bit of track. The shelf follows that small curve as well, but does not change the way it is facing. Then it slides straight again along the second section of track, and with all the books facing in the original direction.
luiz_borges (author)  kelseymh4 years ago
How would those tracks be laid out? How many casters would I need for each bookshelf?
Did you see my top-level comment? I included links to one supplier with which I'm familiar (McMaster-Carr); once you've got the right keywords, you can search for whatever supplier you want.

The tracks should look exactly like your drawing, except with a (hopefully short!) curved segment in place of the sharp 90-degree corners. For the casters, you should definitely use one at each corner for stability, both at the top and at the bottom.

Choose the casters so that they have the right pivoting capbility (see my top level post), and also make sure that they have the necessary weight capacity for your fully-loaded shelves.

My recommendation, for safety, would be that each of the eight casters (four top and four bottom) should be able to support 1/3 to 1/2 the loaded weight of your shelves. That way, if the overhead tracks fail, the bottom casters can take the entire load, with a factor of two margin.
luiz_borges (author)  kelseymh4 years ago
But using only two tracks I would have a 90º degree rotation.
On the overhead track, you install the casters with pivoting posts (the same kind as you find on office chairs. As the casters enter the curved corner track, they rotate around 90 degrees, but the shelving itself does not, and doesn't have to.
Wait a second. What I wrote earlier (3:31 pm) was not correct. You cannot use four casters on the top of the shelves, but just two, on diagonal corners (the corners that match the two pivot points.

It would be possible to use four points of support with crossing tracks, but then you need more complex support bearings to handle the change of direction.
kelseymh4 years ago
Lemonie is correct that what you're looking for is compact shelving. For your application, you could use an overhead track system on your ceiling, with a radius corner in the track. The radius should be at least twice the length of the guide wheels, so they don't jam.

Also, as others have noted, bookshelves are extremely heavy. Book paper has a density of around 50 lb/ft3 (800 kg/m3, and little in the way of air space to reduce that in bulk. If you use typical wood shelving (pine), the density is about the same. So a 1 ft x 2-1/2 ft x 6 ft bookcase will weigh in the neighborhood of 600 to 700 lbs!

You'll need both ceiling and floor casters to make this work (though you don't necessarily need floor tracks). And the overhead tracks will need to be solidly mounted into every single ceiling joist they cross, using lag bolts.

For the floor casters (ball transfers may be a good choice), you should use threaded posts which you can adjust from inside (i.e., from the bottom of each case) to ensure a tight fit to the floor. If the shelves are hanging, they can sway and put a strong torque on the overhead tracks. You do not want a quarter ton of books falling onto your students!