Cup Square Bolts (Coachbolts) 10mm or 12mm x 90mm long, qty.4
Penny Washers, to fit coachbolts, qty. 12
Lock-nuts, Nylon insert, to fit coachbolts, qty.4
Wood screws, 6mm x 90mm long, qty. 4
Wood screws, 6mm x 60mm long, qty. 8
Cord, rope or webbing; approx 1m but allow a little extra for the knots if using thick rope
Wrap shaft of bolt with approx. four layers of masking tape (approx six inches long), to match or exceed the size of the threads.
Use a fibre washer if possible, or glue two penny washers together, either way, get the widest washer available. A small patch of red paint on the front of the front cross bar can provide a useful "Tell-tale" to indicate that the support arms are not fully in place.When the support arm is in place, draw a pencil line around the bottom of the support arm, on the front face of the front cross bar, then remove the support arm and paint almost up to pencil line. The same thing can be done on the sides of the support arm, where it would normally be inside the notch in the front cross bar.
(The photos explain this better than I can.)