While I realize you’re trying to be helpful, this is not sound advice and borders on chicken-littlism. It only serves to create fear, uncertainty, and doubt for new users and could intimidate them from exploring non-vendor solutions. It sounds like you purchased the incorrect ID and OD if you were having trouble.
The risk you outline is vastly overstated if one understands how to purchase to spec. This creates a false notion that only Bambu has the “secret sauce” when it comes to spare parts. I assure you, the opposite is true. There is nothing special about their PTFE tubes that a small amount of educated buying can’t address. PTFE is PTFE—its chemistry doesn’t change with the supplier. This whole hobby is based on a DIY spirit of figuring things out ourselves. Bambu provides the relevant specs in their store. For example, here is the spec for the PTFE tubes:
PTFE tubes are widely available at many hardware stores and online. One simply needs to be mindful of three specifications:
- PTFE
- 2.5mm Inner Diameter (ID)
- 4.0mm Outer Diameter (OD)
Here’s an Amazon search—you can typically expect to pay around $0.40/ft:
https://www.amazon.com/s?k=PTFE+Filament+Tube+2.5mm+Inside+Diameter+4mm
That said, for the amount of tubing you’d use under normal circumstances, Bambu’s prices are low enough that the convenience of pre-cut pieces can be worth it—especially if you’re already meeting their free shipping minimum. Personally, I took both routes and now have a 25ft spool I cut to size. Compared to Bambu’s precut tubes, there was NO difference. I needed variable lengths to build dry boxes and wanted a single standard size of PTFE tube on hand for convenience.