4 Pcs 4mm to 5mm Universal Joint Shaft Coupling with Screws for Motor

There are little tiny c clips holding the pins in . So if the spinning shafts bump dirt or rocks the shaft pops out and poof you are done. What is it about this place that has them selling so many products that are not fit for intended purpose? Could it be an easy way to make money by ripping off people who are not sharp enough to tell what they are looking at? Could it be a complete disregard for the health and safety of the customers? I discovered these stupid little clips because I caught the neighbor kid putting one on his rc car and then revving it up as fast as it would go while holding it up to his face. This is just asking for it , but as we all know , it is something that every kid in the world does every time they get a new toy or toy part. So we did an educational “take it to the lab test” put on our goggles and other safety gear and spun that bugger up to the rated 50,000 rpm of the motor. Now I have a little hole in the wall, and the neighbor boy has a little hole in his heart where he used to have blind trust for adults who sell hobby toys on line. Lesson well learned. If only Amazon would take the kids safety as seriously as they took his 5 or ten bucks.

I use them in my. Rc boats and they work great.

They seem sturdy enough. They're not solid stainless steel but they're not a cheap metal. The things I like most about these is they're precise at 8mm with no wiggle or friction. The boar is 8mm straight to the joint, so if you needed to restrict motion you can push your rod or shaft up flush to the joint bar. Also another nice thing is the joint on these aren't some metal dowel smashed in but rather a pin with snaprings keeping in place so if you so needed you could take it apart and use as a y joint. I personally used these for a motorized actuator and this is the joint that goes on the back of the push rod and front of the rotating arm and it keeps the rods in place well without any wiggle or getting loose, just be sure to file or drill a couple of dimples for the set screws on your rod and it'll hold it tight and no rotating or jiggle.

I used it for the shalt on a tire spare tire hoist. Works great.

nice product

Good

One of the joints was messed up in the first set that I ordered. The joint would only swing freely in one of the directions. Amazon replaced that set, but that adds a lot of unnecessary hassle. I ordered several different sizes of these and only one joint out of ten was broken. The rest are fairly solid and appear to work fine, so I'm ok but the quality control could still use some improvement.

There’s a lot of play in the joints. Depending on your use, it may be ok. For me, they’re going to be used on a drum pedal linkage, turn 60 degrees, then back 60 degrees. It’s going to be sloppy, noisy, and too many degrees of movement of the joint not engaging/turning the shaft if I try using them. Not a precision item. I can’t comment on durability since I won’t use them.Going to return item.