SUNLU Official Filament Connector, Fast Heating Filament Connector for 3D Printer Filament 1.75mm, Up to 240°C, Compatible with PLA PETG TPU ABS PA Nylon, Easy to Use, Pack with 200PCS PTFE Sleeve

As others have indicated, this takes a little practice. Once you get the hang of it, it works as described. Follow the instructions, practice, and in short order it’ll work for you too!

Works as advertised. Very very handy.

My spools of filament remnants were building up. I explored all kinds of alternatives including 3D printed frameworks, home-built joiners, and had saved plenty of PTFE tubing for such attempts.The SUNLU “Official” filament connector was a much easier option. My first use didn’t work well because I pushed the ends much too hard from each side, deforming the resulting weld and ruining the tube. The filament sides do need to be pushed together firmly without smashing them. The included joiner tubes CAN be used more than once by sliding them off one end of the welded filament rather than cutting them off in the included slicer. The most difficult step is holding the angle-cut ends inside the joiner tube for maximum contact since the filament on both sides tend to turn and twist. Since the unit is small and lightweight it can shift and slide around when both hands are holding the filament on both sides to apply pressure. Unfortunately I don’t have THREE hands!Pros: LCD control screen, Fast heating to needed temperature, Over 100 joining tubes included, Compact size, Straightforward operation, Good quick welds.Cons: Three hands needed (!! - Clamping the unit down works best), Small LCD control screen not good for fat fumble-fingers, Easy to burn a finger over heating element (pay attention!), Holding and maintaining the right pressure on each filament out the sides during the weld process. NOTE: Some of the Cons would apply to almost every filament remnant welding technique.Despite the Cons, I would recommend this. It isn’t perfect, but it’s a good product.

Works awesome! Easy to use.

This device actually works quite well at welding filament together but only if used not as intended. The main problem is that filaments tend to curl up near the end of the roll making it near impossible to weld correctly. The moment you press that button to release the top half of the clamping mechanism, it will kink and ruin any chance of a straight weld. The only way to keep it from doing that is to hold the two filament ends while pressing the button which is next to impossible. Here's how I did it.Rather than mess around with the top half of the clamp, I just use the bottom heating element. I heat the element up to temp, then cut 45 degree angles for both filament and connect with silicone tube. Then I just place the joint in the center and wait for it to heat up. The tubing will keep the diameter even, and once it transitions to liquid I slightly push the two ends together. I leave it there for a few seconds then carefully remove the joint from the element and wait a bit for it to cool. Done, a perfect fuse without using the top half.

I use a Bambu P1S, and this thing is so nice to have for all the little runs of filament you have left over after clearing a jam from your extruder. Initially, it IS a little awkward to use when you have to hold both ends together in the PTFE tube and also close and open the top of the heating element, but it really is not that big of a deal as people make it out to be.The included 200 PTFE tubes is quite generous considering you can just slide them off and reuse it again for most splices. So, cutting them would only really to be used for splices between another incredibly long run of filament that you couldn't be bothered to pull it through on.All in all, a really handy little tool to helps prevent waste.

Well, I'm extremely disappointed. I waited months for this to be released and then waited a few more months and finally bit the bullet and ordered it. Let me just tell you right now, nothing about this machine is worth the price you pay. I'll start by saying, it's not all that easy to use. I watched the instruction video Sunlu provides for it, and also several other videos about the unit, and I was definitely able to get it to splice, but definitely not easy like they show. First off the main reason to buy this would be to combine left overs to not have waste. For that, it works, but the filament is not straight like they show in the video. Trying to hold two pieces of filament in the little ptfe tube and put it in place and press down the heat press all at the same time is not easy, especially when they have that end of roll curl to them and are nor straight. You also have to cut around a 45° cut on both pieces and then mate them together in the ptfe tube like a puzzle. So you have to attemp to hold them in this orientation while doing everything else I just mentioned. Once you get the hang of that it's not awful to get done. There are also lots of printed helpers out there but I didn't use them. Next let's talk about the ptfe tubing. They are horrible. They are so very thin (assuming for the heat transfer of things) that they get easily deformed. So easily in fact that about 35-40% of mine were ruined straight out of the package. Once they are deformed, they are no good as they will no longer create the "perfect" diameter they claim they will have, because the defect will transfer to the filament. This also makes it pretty much impossible to properly reuse the tubing. The other thing is when the lid clamps down on the filament and tube, it leaves a small indent on the melted filament, also ruining the "perfect diameter" they claim to make. No matter how hard I tried, there was no way to get a perfect splice with a proper diameter. The instructions they give are to cut the ends at roughly a 45° angle, puzzle them together inside the tube, put the tube in the heater and shut the lid, hold pressure for 1-2 seconds on both ends by pushing them together, wait for the beeping, remove and let cool for 5-10 seconds, then cut off the tube. This does not work. First off, if you let go of the pressure, it does not splice and will break right away. So what you need to do is hold that slight pressure the entire time. Next, when you push open the lid of the heater, it flings open. This has ruined numerous splices for me as it ripped the ptfe tube right out of the heat channel. Next you have to continue to hold that slight pressure for the next 5-10 seconds until the filament hardens. It doesn't take long but you need to find that sweet spot to where you have enough pressure to hold it together but not so much pressure that you bend and ruin the splice, as it's still soft. After that you need to wait like 2 minutes for it to fully cool off before you remove the ptfe. Anything less than that, you risk ruining the splice. Once you finally have all of this kind of dialed in, you can finally use the filament. However let's talk to printing the filament. Once you get all this done you do manage to get a decent splice that won't come apart. The diameter will be nowhere near right but at least it's strong enough to hold. So you go to roll the filament onto the spool. Lol, yeah right. Maybe if you are joining a few decent length end pieces, but not if you are making your own color change filaments and have multiple splices (the other use they claim this can be used for). I put together (20) 100mm pieces of material to try and make a rapid change filament, took about 2 hours and I couldn't even put it on a spool. I just wanted to print a benchy. Once it got that much pressure the splices failed. So I finally just fed it to my printer and printed the benchy out and let the filament dangle from the back and hoped for the best. Stood there and helped feed the filament (60mms print) in so there wasn't too much drag on the extrude gears made it about 45% of the way through the print and I thought, okay, this was bad but at least it did what I bought it to do, even if the effort wasn't worth it, it was printing okay and the splices technically worked. Figured at worst was good for joining leftovers in bigger portions. Then it happened. The biggest thing I was worried about, it completely clogged my nozzle when a big splice hit the hot end. Ruined the print and wasted around 3.5 hours of my night. I tried. I really tried. I wanted this to be awesome, but this is truly a waste of time. I won't even risk using it just splice leftovers. Definitely going to check into others.

Why did you pick this product vs others?:after watching YouTube reviews this looked like the best and easiest to use. it took a few tries and failures but after learning from failures i got it to work every time. As far as I can tell this is the best filament joiner currently available.