Lay the spacer/press plate assembly down so the press plate is touching the table.
Align side pieces with spacer and press plate assembly.
Insure the two are square vertically and horizontally with the spacer, that they are parallel, and that everything is touching the table.
It helps to use angle iron tacked to your table and the sides, so it insures they are vertically square. This also makes it a bit easier to align everything else. Video Help
Also, it may help to use paper shims (see between the sides and the tube to properly space them. Video Help
Tack the sides to the tube on all sides in multiple places except where it is touching the table. Add a few 1" seams to prohibit them from moving.
Do a few light tacks first, and double check it's still square. If not, grind off the tacks and start over.
Insert a new line below
Insert a new line above
Indent current line
Unindent current line
Delete current line
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