Replies

1. 
   Jamie_Buxton | Nov 14, 2003 09:10pm | #1

   I prototyped this once several years ago.  Building the drawers themselves was somewhat challenging, but the bigger problem was the hinge (or pivot, depending on how you build them).   I first tried hinges, but found that the smallest flex in the leaf, or play in the hinge pin, allowed the far edge of the drawer to move up and down more than I liked.  That is, it was difficult to make the drawer fronts completely parallel, and stay that way.    I tried a pivot rod -- one rod to pivot several drawers.   That eliminated the problem with the hinge leaves bending, but still left the issue of play between the rod and the hole in the drawer.   I concluded that to make this design work really right, I should use the single pivot rod, and then invent some little adjustment mechanism at the bottom of each drawer.   It would be a little like the adjusters on cup hinges, where you build the cabinet and then tweak each drawer in place.   The adjuster would move the pivot point a little bit to align each drawer so the fronts are parallel when closed.  I decided that this was too darn much work and abandoned the concept.

2. 
   4DThinker | Nov 14, 2003 11:07pm | #2

   I've had several students try similar projects in the past...  And as of yet none have succeeded to solve the problems mentioned in the previous post.  The concept works OK on small boxes, but as size increases gravity increases cubed.  So to have only one point of contact with the drawer cantilevering out from it will require a high-precision or adjustable hinge/pin connection.

   So if you figure it out, please show us how. 

   4DThinker

3. 
   ron61 | Nov 15, 2003 12:13am | #3

   I haven't made drawers but have made Lazy Susan much like what you are wanting to do. What kind of hardware are you using?

   Just an idea > If each drawer was  in its own box "box behind the face frame" and in the bottom of the each box it had a circular groove for a ball bearing  for the drawer to ride on and a pivot on the drawer - What do you think?

   Have you looked at the old revolving book cases? they had a similar ball that the rode on so they could turn smoothly.

   Ron

   Who Ever Has The Biggest Pile Of Tools When You Die Wins

   
   

   ---

   Edited 11/14/2003 4:25:27 PM ET by Ron

1. 
   macalex | Nov 16, 2003 04:38am | #4

   As I get closer to a first prototype this challenge looks more daunting, and you guys haven't helped!

   The rotation or 'hinge' is the issue. I figure on beefing up the apex of the pie-shaped drawers with a chunk of something 'beefy', like American white oak, glued and screwed in. Then I'm going to drill a hole (about 1 to 1.5 inch diam) in the insert and glue in a length of steel tube, flush with the top and bottom of the drawer. I'll stack the drawers on another length of steel that's an engineering fit inside the piece glued into the corner piece.

   Whether this works will depend on the strength of the corner of the drawer, and the goodness of fit of the steel tube.

   Back later with a prototype review!

1. 
   robkress | Nov 16, 2003 04:21pm | #5

   I have to agree with the other guys that your fit of the drawer front is going to be an issue.  But I like your idea of the metal rod.  Perhaps though you could make it 3/4-16 fine thread, all threaded rod.  This size could easily hold up your drawers if it is supported in between each drawer.  Then go get some cheap ball bearings (how many drawers are there?) and socket the ball bearing in the top and bottom of your pivot block (I like that beefy block affair).  Then use jam nuts (regular hex nuts but only thinner) to adjust the height of each drawer on the rod.  The use of locktite would be a must to hold the jam nuts from continuing to move after the fact.  Then the only thing that you have to worry about is getting the rod absolutely straight up and down and drilling the bore and counter bores in your pivot blocks absolutely perpendicular to the plane of the drawer.  This could work but even with my experience as a metal machinist, I can tell you that your order of operation will be critical.  As will be your strict control of sameness between parts and the precision of the carcass.  Considering though that you are willing and capable of doing this type of precision work, I don't see any reason that it wouldn't work out well.  The only thing then to worry about is the inevitable movement of the woods after the project is all done.  And there's nothing to do about that other than plan for it and hope it doesn't get so bad as to bind the drawers (you know, much like flush mounted cabinet doors).

   One last note, try to make your pivot bearing at least 2 1/2 or 3 times longer than the diameter (so maybe 2" or so long for a 3/4" rod..... but how tall are the drawers?).  This will ensure more than a lifetime of function and no sag at the bearing.  And if you don't like the ball bearing idea, you could also use a sintered bronze sleeve or even reinforced teflon or nylon (also available at the bearing shop).  These are essentially bearings for low rpm service.  Don't use steel tube for a bearing.  Believe it or not, that will wear away and squeak for sure once the grease / lube has dried out.  True bearing material (sintered bronze or teflon impregnated something or other) will do both of those things much less.

   As to the fit of your bearing and rod assembly.  I have used this same type of affair many times in my work as a machinist and what you'll find is that bearings (those things that are sold at the bearing store and are intended for such service) come is sensible, nominal sizes.  Therefore, if you go out and pick up 3/4-16 all thread rod and get a 3/4" bearing to match, your fit will essentially be guaranteed.  Nothing to think about.  Of course you would have a better fit if you used hardened, ground, and polished solid rod but then you would be missing out on the adjustment affair.  And the fit between your threaded rod and bearing will be plenty peachy (better than you would be able to measure most likely).  And sintered metal or plastic sleeve bearings (heck even cheap ball bearings) will be very inexpensive for this project (a few dollars a piece maybe).

   Good luck,

   Rob Kress

2. 
   ron61 | Nov 16, 2003 10:46pm | #6

   I just don't know about hanging the drawers on the bar  with out some kind of support along the outer rim side of the drawer to carry some of the load. 

   Sounds like by the time you Beef up your block and get the drawers loaded?????? the drawers are still hanging by the corner. How long will that last????? How many times will they be shut hard?????? Putting lots of stress on that BEEFY block and tweaking the drawer out of alignment. How much space is all this taking out of your drawers???

   Sounds to me that the drawers jam shut or never get them to close after some use.

   I still think you should think about supporting the outer rim of the drawer some how like I spoke of before.

   Time you get the drawers full of files and paper work they will be HEAVY.

   RonWho Ever Has The Biggest Pile Of Tools When You Die Wins

4. 
   aksophie | Nov 18, 2003 03:18am | #7

   I don't follow your explanation. Which faces of the drawer are exposed? What does the cabinet look like that surrounds the stack of drawers? Can you post a drawing?

   I may be able to help, but to attempt to do so without clearly understanding your intent would be a waste of time. And right now, I really can't fathom what you are trying to do.

1. 
   macalex | Nov 18, 2003 12:27pm | #8

   We need some sketches, but my scanner is buried under undone work and I'm not that proud of my freehanding anyway.

   The drawers will sit under the left side and right side (when sitting) of a large Australia-shaped desk (under Eastern Victoria and Southern West Australia). They'll be anchored to the underside of the table top by the rod/pipe from which they rotate, and the rod/pipe will be anchored to a plinth on the floor. Their only support will be the steel rod/pipe that they rotate from, and they will not be encased in a cabinet.

   Probably makes it more confusing, right?

1. 
   DBishop | Nov 19, 2003 12:04am | #10

   It sounds to me like you are looking for the reverse of a corner cabinet that I've seen here in the US.  It fits in a corner of a kitchen and if it were out of the cabinet it would be three flat 3/4 circles with doors creating the corner for the cabinet fronts.

   I don't know how they make those but I would imagine you could use that hardware idea in reverse...

5. 
   user-134407 | Nov 18, 2003 10:04pm | #9

   How about removing the issue of the pivot having to do all the work, and thus have to handle a large amount of precision under stress? Make a curved back rail under each drawer, and have the drawer ride along that, either wood to wood, or some type of small roller. If you put a stop such that the drawer could only rotate open to some say 85% of it's total arc, then there would be a fair amount of remaining support for it even when open. If the drawer fit snugly between the bottom rail and the rail for the drawer above, then the pressure up onto the bottom of the upper rail would help keep it from tilting down when fully open.

   Just a thought - easy for me to say, as I couldn't imagine my skills being up to creating and fitting the drawers and rails. Maybe someday...

   But a really nice sounding design.

   Jim

1. 
   robkress | Nov 19, 2003 03:36pm | #12

   Jim,

   Hey, I like this idea.  Perfect solution if you ask me.  And to add to that, he could use regular coutertop laminate.  One piece glued to the "case" and one to the drawer.  These pieces of laminate can be routed to shape and run face to face.  This actually makes a qute supreme bearing, sliding surface that will last just about forever.

   Rob Kress

6. 
   aksophie | Nov 19, 2003 01:06am | #11

   Here's an idea that will work and (I think) look cool;

   You need to build the pivoting mechanism yourself. Get some 1 1/4inch OD pipe that is the height of a drawer. Either press in a store-bought ball bearing at each end, or make your own bushings, to fit, out of UHMW nylon. The inside diameter of bearing or bushings will match the size of the pivot rod you choose (3/4 inch ought to look good). Weld or silver solder steel tennons (or you could use brass) onto the pieces of pipe, these will fit into through mortises that you cut into the ends of the drawer sides. You have to cut the ends of these drawer sides to match the diameter of the pipe, then mill the mortises. Glue onto the tennons with epoxy or poly glue and perhaps use a couple of cross pins if you don't trust the glue.

   You will note that the joinery of this rear drawer corner isn't conventional, but neither is the piece of furniture.

   I wouldn't worry about adjustment ability unless these drawers are going to be very large and carry a lot of weight. If you fabricate this all carefully, there will be minimal or no deflection/sag.