I am in the process of designing a custom backpack and wanted to include a Delrin rod (like in my Deuter Speed light 10 and 20 daypacks).  Does anyone know where I could purchase one of these rods?

There are many places that sell delrin rod of various diameters, such as TAP plastic, interstateplastics, USplatic, grainger, etc.  You can probably obtain it locally (look in yellow pages under plastic), or it’s easy enough to mail order.  Measure the diameter of the item you’re trying to match.

Thanks.  I did the searches you suggested and found them.

Have a look at McMaster-Carr.

http://www.mcmaster.com/#delrin-rod-stock/=39dpk1

They have very good prices and small minimum orders.