CC Friends:

I am doing a large Sweet 16 cake - 16", 14", 12", 10" and 8" - the 16" and 14" are going to be cake dummies, the rest real cake. As part of the cake display, I would like to sit the cake on sort of automatic revolving display where the cake will slowly spin throughout the party. I have looked for heavy duty rotary displays, but have found none that would hold the weight. Then I checked for like rotating christmas tree stands, but those are used with the actual pole of the Christmas tree. Does anyone have any ideas???

could build your own.

relatively easy -- very scaled down version of a theatre turntable

http://www.dxarts.washington.edu/courses/490Form/readings/revolve.pdf

except for this small size use ball bearing casters instead of the upside down wheels.

http://www.wttool.com/product-exec/product_id/15667
http://www.outwaterhardware.com/catalog/images/pdf/cat56-424.pdf

would make it a 24 in round and put it in a 36x36 box to allow for all the stuff (motor, gearing that goes underneath)

size could be adjusted as see fit: example -- 22" round in just a 24x24 box (tighter fit underneath)

diagram shows basic idea with motor place fully under the turntable and using direct friction drive (small rubber coated wheel on motor shaft resting on wood or steel plate connected to main support)

gearing will be essential
http://www.teamdavinci.com/understanding_gear_reduction.htm

direct drive (chain and sprocket -- salvage from old bicycle) or belt drive is best for least loss of torque.

will need high torque motor

and if possible one that can be controlled by a variable speed control

most HS gear heads can build you one!

(been there done that for Brigadoon! with a HS tech crew -- we used old fashioned manpower to turn it!)