Supporting a Giant Lazy Susan

A brainstorming session on the mechanical aspects of a super-sized-and-customized Lazy Susan. January 21, 2007

Question
As part of a storage solution I am building, I need to build a giant lazy susan. It is in a space with full frontal access 4'x4'x8' tall. Thus the platters are just under 4' in diameter. There are six of them.

My original thought was to put a traditional lazy susan type roller bearing under the centre of the bottom platter along with 4 casters - 1 at each of the quadrant points. Then space the other five up through the 8 foot ceiling, using some simple method (like a bolt through the centre pole) to hold the centres, and tie the outside edges of all of them with 4 pieces of angle iron - again, one at each quadrant point, ending at the bottom over the respective caster.

This method is somewhat attractive because it is relatively simple, but I think I'm shying away from it because: a) by the time those platters are loaded up with canned goods, cases of pop and beer, and all manner of assorted junk, this thing could weigh 1000 lbs, and that might be totally unacceptable to spin (remember, all the platters are tied together in this scenario), and b) even if it wasn't too bad to spin, I gotta believe those casters would wear a groove through the MDO base in not too long a period of time.

So I've puzzled over a number of other scenarios including:
- Each platter individually supported (like a regular lazy susan) but have a custom machined sleeve with bearings as the support for each.

- Individually supported platters but instead of expensive machining, and possible questionable support and balance even then, simply pin the centre (through-bolt with a washer) and support the perimeter with casters (or those single roller ball bearings) attached to the sides and back of the enclosure. The back attachment would also have a caster/rollerball on top to prevent tipping to the front in the event of uneven platter loading.

All of these methods have some major unattractiveness in either cost or pain-in-the-ass-ness and complexity, so I thought perhaps someone had traveled this ground before and might have some ideas. Hopefully something wonderfully simple that I totally overlooked.

Forum Responses
(Cabinetmaking Forum)
From contributor D:
This is a very interesting problem. My first thought about this was drawing on my original experience in woodworking - telescope making and design. As any reasonably experienced amateur astronomer will tell you, by far the best way to get a large, heavy reflecting telescope to spin around in azimuth (direction around the horizon) is to mount the thing on a bearing surface of ebony star Formica (or substitute glass board) riding on small Teflon pads. In the scenario where all the platters spin together, or even perhaps if they spin independently, the bumpy Formica and Teflon interface moves like a dream and will never ever fail. The heavier things get, the better it works.

I'm thinking the inertia of that massive six tiered assembly will be too great potentially, and that you'd be better off making the platters spin independently no matter what you use to actually let it spin. I would worry about some kid making a game of spinning it fast, and then accidentally getting an arm stuck in it or something. With hundreds of pounds moving around, it won't stop easily and I could see a lawsuit down the road.

I like the idea of each platter loosely clamped in a trio of brackets that would be bolted to the sidewall of the 4' diameter by 8' high cylinder. If you make the big tube out of framing material or plywood strips with bending plywood forming the inner sleeve, then have some brackets made that could be notched to the sidewall height of a platter. I'm thinking even three of these brackets would be sufficient provided the platters were rigid enough - say, with a floor of 3/4 plywood. The brackets could have Teflon bearing surfaces top and bottom. They could be made to be re-positionable vertically so you could adjust the spacing of the platters. What do you think?



From contributor P:
This may or may not be feasible, but how about mounting each shelf on its own steel tube - the lowest shelf on the largest diameter, each seceding height on a tube that nests inside the first, all surrounding a rigid support connected to top and bottom of case. I have spent exactly 20 seconds thinking about this, so the details will need to be worked out, but it should work.


From contributor U:
Why not put in fixed shelves (probably supported by cleats on 3 sides) at the appropriate heights, then install a lazy susan bearing and circular shelf on top of each fixed shelf? That way, each shelf will spin independently, and each bearing only has to support the weight of its own shelf.


From contributor T:
The 17" Super Swivel has a load rating of 700#. You can use a standard swivel at the top for adjustment and as a follower and it will also take some of the weight. The only contact I have for this swivel is Specialty Hardware.


From the original questioner:
Great, thank you, all. This is exactly what I needed to get thinking outside the box (so to speak) again. The creative juices are flowing once more.