It is just a big padded solid plywood wheel. Laid flat and built on a strong spindle and bearing system. The main downfall of the round table is it can occupy a lot of space. Takes a thirty to forty foot area of enclosed space. One built 20 foot to maybe 24 foot circumference could be done with proper carpenter/mechanical skills. That would be the limit and 16 foot should be the smallest size. Mine was around 16 or 18 foot across. Worked very well for me.

One of the secrets is to set the over head pull area one foot forward from center of table Not dead center. Dog will run out in front and fall back to center. Dog should never run in the back of table. Cheers