When assembling a canvas Sukkah always insert the pipes from the shorter
side into a corner fitting FIRST as far as it will go and tighten the
hex screw. Then insert the pipe from the longer side into the other end
of the corner fitting as far as that will go and tighten that hex screw.
This will insure that the canvas will properly fit on the frame.
Corner and "T" Fittings
for Canvas Sukkah
Also remember that if the canvas does not fit snugly the frame is
somewhat adjustable by adjusting the position of the pipes on the frame.
To do this, loosen the hex screws on the fittings, move the pipes until
a good fit is affected, and then tighten the screws on the fittings.