4Pcs 3.17mm Flange Coupling Connector, Rigid Guide Model Coupler Accessory, Shaft Axis Fittings for DIY RC Model Motors

Very good quality. Would highly recommend.

Nice product

They seem to work great if you add Loctite or super glue to the little screws, they tend to fall out. I think it is because the hole the screws screw into are a bit larger than it should be so it goes in loose. Without extra reinforcement the screw will fall out. The look well machined, seem to be durable, easy enough to install after you fix them up, good value for what I paid!

Worked perfectly for the project I was making

Perfect Machining and Great Design – Each Flange Was Flawless The manufacturer can be rightfully proud of the superior craftsmanship of the workers and high Quality Control inspections. Each flange was perfect: dimensions correct, NO dangerous sharp burrs left over from machining, chamfered guides for axle hole, chamfered beveled guide to screw threads for easier screw starting, and smooth screwing perfectly shaped internal threads. It was really polite, or something, that the manufacturer included the tiny Allen Wrench for the M3 socket head grub screws.

Perfect for 1/8” rod when making whirligigs. Used to mount drive shaft to the blade

Worked as advertised

I've used these for a number of applications. They're fine as long as vibration isn't an issue. If there's even a little bit of vibration in your assembly the set screws quickly loosen and render the piece useless. I'd happily pay a bit more for a piece that doesn't have this problem, but I can't find a better version.

Nice quality, used to attach to output 14m shaft of worm gear reducers (after removing key) etc.

Fits the three 8mm rods that I needed them for. Threaded screw fits properly and snugly. I had a bit of a laugh in that the resealable package ("ziploc" style) was heat-sealed shut BELOW the reseal, so after breaking the heat-seal (cutting it off) you couldn't reseal it anymore.

perfect fit for the proper pipe

Me gusto los tiempos y el producto es de excelente calidad.

Pretty good product. Only complain is the little holes you attach whatever to it with, they are not threaded, and so tiny there finding nuts and bolts to attach something to it is a challenge. I just welded a 3/8 nut to the top of it and found that to work very good.