PTFE Tubing Quality

Hey everyone!
I finally had to change one of the internal PTFE tubes on my AMS (slot 1) because that is where I run my go to black filament. It wasn’t a major issue but this is the second time the factory PTFE tube has just worn through from filament use. I have run Capricorn PTFE on every other printer and can honestly say I have never had this issue with it.

I guess I am asking what everyone else’s thoughts are on the comparative quality of the PTFE from factory versus aftermarket? I have printed for years on Capricorn without issue but not at the speed of Bambu and I am playing with the idea of replacing all of the factory white PTFE with Capricorn blue tubes and seeing if there is any durability differences or not.


The Bambu lab tubes have a larger inner diameter than standard tubes so that the filament moves freely in the tube. Since the outer diameter is still standard, it means the walls of the tube are thinner than other PTFE tubes, so this may make it wear out faster.

You shouldn’t use other PTFE tubes unless they also have a larger inner diameter or you will cause worse problems for your printer.

Are you using a lot of Carbon Fibre, glow in the dark or other abrasive filament in your AMS?

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No, actually I’m using almost exclusively PLA. I have used carbon fiber previously but not more than one roll and in a different slot. Also, any PETG was in other slots. So slot 1 has been exclusively PLA.

I didn’t realize that it was a larger ID. Are you speaking from experience that they would cause problems?

Not from my experience. Bambu labs warns about the issue and I have read about people having issues when using a non Bambu tube.

How much printing did you do before the first replacement? I have had my printer since November only using with AMS and haven’t had an issue.

Oh, I’ve had the printer for almost a year and have unknown hours on the printer. So the tube has played a long time but it was just something I was considering because two separate tubes blowing out in just under a year versus several years on the same Capricorn tube…

Was it the same AMS slot that wore out both times?

No. The first one to wear out was from the AMS to the X1C. This is the first AMS slot to wear out. Like I said, it’s not a major hassle but just makes me wonder if better quality PTFE tubes would be better.

Standard Capricorn PTFE is 1.9 or 2mm ID, 4mm OD. Bambu uses 2.5mm ID, 4mm OD. Capricorn makes one that is EDIT: 3mm ID, 4mm OD, they call it their reverse Bowden PTFE tube. I can’t find a Capricorn one that is 2.5mm ID and I don’t know whether the 2mm one would give problems. There must be a reason Bambu went with the 2.5mm ID, rather than the standard. Could have been that the standard PTFE of 2mm was giving feed issues. As Capricorn tuning is better quality than standard PTFE, it may be ok.
I think you’ll need about 3 metres to replace every PTFE tube, depending on where your AMS is located.

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In this link Bambu says both the 2mm inner diameter and 3mm inner diameter can cause problems. They specifically mention Capricorn.

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The biggest issue I believe is when some filaments run through the AMS feeders and extruder it knurles it, which then increases the diameter and therefore the chance it may get caught up or cause drag in 2mm PTFE.

Oh, good link.
I was looking at the Capricorn website this morning and they have a kit for the AMS but it says the ID is 3mm vs the Bambu Labs 2.5mm.

So seeing BL address that specifically does help.

Good catch!

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I bought some 2.5x4mm off Amazon that doesn’t seem as strong as the BL tubing. It seems easier to kink. I just ordered a bulk PTFE spool from BL. I’ll try to use up the Amazon stuff on straight-shot pieces like in the AMS.

if you try it, can you report here how you feel this change please ?

Did you get the clear “uxcell PTFE Tubing Hose” from Amazon? I notice a review that says it’s “PEP” tubing, whatever that is. It looks like the clear tubing used in hospitals like PVC or something. PTFE is not clear, so I’m avoiding it.

I got 3mm ID 4mm OD PTFE as it’s kind of close. I can’t find any 2.5mm PTFE. I think BL bought it all.

How did you order a bulk PTFE spool from BL? Customer service? I can’t find anything other than precut tubing.

Get it from the “spare parts for AMS” heading - Bambu PTFE tube. Best value is to choose the 4000mm (4m) and cut it to the required length yourself.

So far I had no need to replace any tubes, but then again the machine is only a few weeks old…
But in the past I learned from my other printers that there IS significant difference in PTFE quality, durability AND INTENDED USE.

For starters these tubes come in various inner diameters and wall thicknesses for a good reason.
A bowden system for example requires a fit with very little wiggle room.
While a pure transport system like for AMS relies on larger inner diameters in order to best cater for the high print speeds and many different filament types supported.
You might have noticed that some plastics give you a slippery feel, others feel like, well, plastic, and some appear more or less non-slip.

In the past I great results with PTFE tubes meant for MIG welders.
Sadly my Chinese supplier no longer has any stock as industrial welders no longer use teflon liners for the really thick wires.
BUT and that is maybe of interest here:
I did have great success with those stiff air hoses uses for the smaller actuators on pneumatic machines.
You know the colorful PU type of hoses.
The 4mm OD, 2mm ID ones work just fine and are direct swap.
Dirt cheap compared to Teflon as well.

Like only being good for low friction filaments like PLA.
You CAN get PU contamination if you fail to check every now and then for wear and tear - if using a 0.2mm nozzle this might mean a block that is hard to clean out.
I cut a tiny ‘blob’ out of the foam from a stubby holder to act as a cleaning plug.
Every 5 or so rolls I push it through to clean out possible PU and filament dust and particles.
It also helps to judge the inner surface quality as in badly worn areas you feel an increased resistance.
Yes! You need to change the tubes more often than you would change high quality Teflon tubes.
But if you do print a lot and see these tubes are factor in your printing costs give PU tubes a try as they come dirt cheap if you order a roll…

What @RMB says. I got the 4000mm “spool” from BL. It doesn’t come on a spool–Just wound in a coil and put in a bag. When you click on the PTFE at the Bambu Labs’ sight, it takes you to the choice screen as shown by RMB. That’s 157 inches for us country folk.

The stuff I got off Amazon is not clear. It’s the same color as the BL tube but seems a little softer.

Just an FYI, the PTFE Bambu Lab uses is 2.5mm ID, 4mm OD. Capricorn and most other 3D printer tubing is 2.0mm ID and will apparently lead to issues when used in the AMS.

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I did not have to change the tubes yet but will keep that in mind for sure.

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The tube is listed as a consumable. I’ve run coutless hours and have had to change toolhead PTFE once, AMS I’ve replaced twice, but I replaced because one tube each time, and since I’m in there, why not. The price is $4 so no biggie and I keep all consumables on hand. I’m odd that I have backups for my backups.

I’d look at the store and buy at lease one extra of the consumables. Just mt $.02