FAQ: Wooden Table Mechanism

What about a 6 piece design?

The current design is for a 48″ (1200 mm) diameter mechanism. It is quite dense and I do not feel optimistic about adding 50% more mechanism without compromising the function and reliability. However, circles have the benefit of exponential area growth, a 60″ table would provide 56% more surface area and may be practical for a 6 piece design. (A mechanism over 60″ (1500 mm) in diameter will require multiple sheets of plywood or specialty materials I’m not aware of. Birch plywood is available in my area in 60″ x 60″ sheets (1500 mm x 1500 mm).)

How big is the table?

The mechanism with skirt is 51″ (1295 mm), the top panels as I have them cut are actually 52″ (1320 mm) total diameter, expansion increases it to a maximum of 67-1/4 ” (1705 mm). See diagrams below for exact expanded size.

How much does it weigh?

230 lbs or 104 kg.

Are the metal components easy to find?

Yes, the linear bearings are available from several sources online and the size requirements are not exact; i.e. I used a 12 mm shaft but if a 16 mm is more easily available it will work just as well. The other metal components: 12″ (300 mm) lazy susan and spring loaded gate hinges, are easy to find and very affordable.

What do you think about Walnut/Cherry/Mahogany/etc hardwood for the panels?

I love hardwood construction but this is a place for veneer. The panels must remain very flat without reinforcement and even carefully selected quarter-sawn wood will expand and contract. The ultra-high end Fletcher table uses aluminum honeycomb panels for their “foundation”. A wood core, thin fiberglass layer and veneer on top would probably be the optimal balance of cost and function. If you know of any other suitable options please let me know! scott@mechanicallumber.com

I’m colorblind, will I have difficulty understanding the plans?

The photos are in color but all diagrams and drawings were designed for black & white printing. You should not have an issue.

Isn’t the expanding table concept┬ápatented?

It was, the original expanding table idea by Robert Jupe in 1835 and the modern self storing iteration by David Fletcher in 2002, #GB2396552. The 2002 patent was filed in Great Britain and expired 5 years later in 2007 due to “non-payment of renewal fee.”

Table Surface Dimensions

Table Dimensions Imperial

Table Dimensions Metric