PTFE Teflon tubing 10ft - 3mm ID X 4mm OD for 1.75 Filament Bowden 3D Printer - Allen Tech PTFE Teflon Tube

Some 1.75mm Filaments for 3D printing are NOT 1.75mm some are actually up o 2.1mm meaning your common 4mm OD / 2mm ID tube won't cut it. Glow in the dark, word, carbon fiber, etc. can be greatly varying diameters and the run of the mill PTFE tubing won't work. I bought this and works fine with one caveat; make sure the spring teeth in you hot end assembly is tight of the thin PTFE tubing that this is may pull loose.

This is good to run between a spool (or filament dryer, like I did) and an extruder, as it's very loose and won't add appreciable drag while your extruder is pulling the filament. Because it's less draggy, it's better for this purpose than what you'd place between an extruder and hot end. However, it's useless for a "regular" Bowden setup (between extruder and hot end.) The ID (inside diameter) is too wide, allowing the filament too much freedom to move around at random angles, effectively changing the amount of pressure according to where the nozzle is, and that's no good. I tried that and found that it lead to weird inconsistencies in finish, especially at the top layer. So, for a regular bowden setup, use something with a slightly narrower ID.

Needed longer tubing for my ams lite so I can mount it on the header of my work bench and it's been working great. First roll came smashed so I ordered a replacement and this one had just a couple inches smashed so I just cut it away instead of dealing with returning it again. Don't know who's at fault but I'll try a different brand next time and also go back to grey like the original is. Grey just looks better imo.

This is the PTFE tubing I want feeding into an extruder on a 1.75mm filament setup. The 3mm inner diameter gives the filament enough clearance to move freely without adding unnecessary drag. I've used tighter tubing before, and that extra friction can create feeding issues that are easy to mistake for an extruder or tuning problem. The 4mm outer diameter is a standard size, so compatibility with common fittings and printer hardware is straightforward. The tubing is flexible, easy to route, and simple to cut to whatever length a build needs. For printer builds and filament paths where low resistance matters, this is a good size and a good value for the amount included.

Works great

the 3mm id is perfect for 1.75mm filament. Gives you a lot more slack resulting in less wear and tare on your extruder

I needed to replace the small PTFE tube in my Ender 3 KE upgraded hot end. This tube fit perfectly and dimensions matched the original. I only needed a small piece, but the extra will be nice to have on hand. Highly recommended!

Started having some issues with the stock PTFE tubes used with my Bambu 3D printer and AMS, guessing they just got worn down from use. But just in case I swapped to this slightly larger ID tubing hoping it'd reduce the resistance a bit, and it still fit all the fittings just fine and things seem to be working great, so it's at least as good if not better than the stock tubing.

Very thin but very low resistance for pulling filaments

Unlike the claims made by certain other vendors, this turned out to be real PTFE tubing. With the generous 3mm inner diameter, this solved all my filament feed issues. Well, all the issues related to the Bowden tube anyway! <lol>

As described, matches the listed specifications

Works well low friction reverse Bowden tube.