What was installed new in 2008 was broken by previous owner, and I wasn't able to find replacements that fit at the local hardware store.  Instead of letting the wife spend big money by having the rods replaced, I decided to re-engineer them stronger by adding plastic around the hole, and making them solid instead of hollow, like the original.  You can see in the photo how the added plastic increases strength.  

Printed with 0.2mm layers in PLA+ on the Prusa XL.  Orient it on it's side, and you won't need supports but you may need a brim.  I didn't on my printer, though.