cardboard tubes

where to buy them

Locally available:

• FedEx — 2", 3", 4" — typically used as a shipping container
• UPS Store — 2" — shipping container
• Home Depot — 8", 10", and 12" — typically used for concrete forms
• U-Haul stores — they have zero cardboard tubes, despite some stores having many packing materials

Online, there are many options, but the shipping fees are high:

• Amazon
• Uline — they have pretty high minimum quantities
• McMaster-Carr — they have minimum quantities too

how to cut tubes to length

1. Create a round plug of wood that just fits inside. I would need a separate plug for each size I regularly use. These circular plugs don't have to be perfectly circular though, since cardboard tubes are somewhat flexible.
   • cut circles with just hand tools [2] [3]
   • cut circles with a hole saw
   • cut circles with a dremel
   • cut circles with a jigsaw [2]
   • it isn't too difficult to build an ad-hoc lathe
   • also, variable-radius hole cutters exist
     • Though they generally get bad reviews. (although it's possible that it's difficult to get the feeds and speeds right)
     • You must use a drill-press, not a hand-held drill.
2. On the outside of the tube, wrap with painter's tape to minimize tear-out.
3. Cut with a utility knife.