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

I first saw this product being used on 3d print channels I watch on YouTube and decided to give it a try. I have to say it worked right out of the box and gave me a clean weld that will pass through my printer with out issue.if you use a 3d printer and have a lot of end pieces of filament like me,this product is a no hassle way to use them up without a lot of hassle in welding them together. There is a small gap in the welding but it is not noticeable without magnifying the joint. I tried pulling it apart but it wouldn't break.

A lot of people report problems with this device, but I’ve had a a lot of success. Like others have pointed out, if you follow the directions and don’t rush it, it makes a great, smooth connection. I have a Bambu P1S with an AMS and have not had an issue with any of the joints.

This product works great. You do need some practice to get it right but it is easy to use. Before you buy it make sure you have an end/block with a usb port and that the end/block is the right one. It requires a 5V 2Amp end/block for it to work. We did not know that when purchasing and had to buy an end/block that was compatible for the display and functions to work. If you have the wrong end/block the power button displays but when you press it it will turn the device off. Other than the end/block specification it works great and we haven’t had any issues!

Works like it should. I failed at the first two attempts, learned how much pressure to apply to the ends and third, forth, and fifth attempt came out close to perfect.

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.

I waited to write this review because I wanted to see how well this worked and how the filament held up over time. I'm extremely pleased with the results. I did have to print a filament holder off Maker World. The person has a video tutorial and review too. Without it it's hard to hold both ends and close and open the lid. This is something inexpensive the manufacturer could include to make this superior and easier to use than other products that have that problem as well. Overall, the welds are spot in for diameter. I don't have to sand them and could print right away. The welds are more flexible and hold better than the original filament and the print quality is no different. It does take a few practice attempts. With the filament holder it was less. One more tip: I used a few seconds less than the timer indicated and had better welds. That may be my filament. I'm extremely happy with this product and recommend it over other options.

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.