I purchased a portable table at the Houston Quilt Festival several years ago, and this is how the shelf is connected on it, but they countersink the heads of the bolts, so there is no bump. And with a wooden table, you could use wood filler to fill the holes and make the desk top smooth.
Originally Posted by
yel
i think if you got a piece of wood as thick as the space is between bottom of the top and the top of the bottom shelf{where the machine is ] and 4 carriage bolts ...you will have a small bump but out from the machine where the bolt is [they have rounded heads your fabric should not get caught on them ] and maybe one in the back of machine ....can't see how much room is there ......but that would make the shelf solid and not vibrate so much ...good luck