Fair warning, this only fits certain types of cheap particle board pegboards like what I have pictured.  If you have metal, plastic, or just slightly different than what my hardware store sold me, you may be wasting your filament.  The only way to make it more secure would be to redesign it to use 2 rows of pegs and I don't have any interest as this works for my pegboard and it may work for you who knows, but you have been warned.  

  pegboard shelf 5 pegs wide. Printed with supports from build plate only.