I bought some PC4 M6 fittings from the Bambu Lab shop, and I also got the PTFE tubing from Bambu Lab.
The problem I’m having is that the tubing won’t slide through the fittings. I’m cutting the tubing with a tubing cutter, and I measured the average diameter at 4.1 mm. As far as I can tell, the fittings don’t have a chamfer on the inside; the tubing goes in a little way, but then gets stuck. I can only push it through with pliers, but then the tubing breaks. If I try to insert it from the other side, it’s extremely difficult, as if the fitting is too small. Now I’m not sure if the PTFE tubing is too thick or the fittings are too small. Has anyone else had this experience?
Can you provide a link to the specific part you purchased?
I am unaware of any Bambu pneumatic coupler (industry term) that has a pass-through feature being sold on their store. Which is why I asked for the link. The PTFE couplers I have purchased from their website are all designed to connect two tubes, one from each side, that’s why it’s called a “coupler” not a connector.
Pass-through couplers do exist on the market. These are two I purchased not too long ago that works with the standard 4 mm OD PTFE tubing that Bambu uses. These are well suited for use in DIY dry-boxes. It allows one to use a single PTFE tube as a guide tube. Couplers can often snag the filament on initial feed at the tube boundaries.
One word of caution: Amazon suppliers often mislabel inventory, or more commonly, Amazon comingles inventory from other sellers so there is a risk you may not get what you ordered. Even though this link is copied directly from my order history, you should verify the part upon arrival. If it is not what you ordered, return it within the 30-day window. I had to go through three parts before receiving one that actually had a true 4 mm OD pass-through.
I remeasured the PTFE tubing from the old Bambu Lab order, and it’s exactly 4 mm. It fits through the PC4 fittings. So the problem must be with the tubing I received now. It’s a bit too thick.
Ok. Thanks for confirming. Yes, those are designed specifically to NOT be passthrough so the product is working as designed.
It may help to understand that the term “connector” is what the 3D printing industry calls them. They are actually designed for pneumatic tubing and the industry name is quick connect fitting or somethings push-to-connect fitting. They are designed to carry air not filament although they work perfect for that too which is why they are used on 3D Printers everywhere. If you’ve ever done your own plumbing using SharkBite’s, they employ the exact same mechanical principle except for plumbing pipes.
Save your self money and also become independent of Bambu, here’s a search term on Amazon for PC4 fittings. As you may be aware PC4-M6 is 4mm OD tube with M6 outer thread and PC4-M10 is with M10 outer thread. This search will also list kits that include the correct PTFE tubing for 3D Printing but in all honesty, that stuff is so ubiquitous, just by a 3m length and keep it on hand. You will eventually find other uses for it. I go through about 20 feet a year with various projects such as dry boxes and printer maintenance.
I recently stumbled upon this transparent PTFE which is perfect for using on a material management system. You can actually see and follow where the filament is traveling. It makes feeding diagnostics much simpler when you can easily see where the filament is traveling. https://www.amazon.com/Ultra-Smooth-Filament-Extruder-Compatible-Transparent/dp/B0DM96N8QF
