Big thanks for that video! I was unsure how to fix my 4in 3-Jaw on my 8x14. Although the spindle runs true after loosening the massive factory pre-load torque on those poor bearings*  the chuck is  a grimy stiff and binding experience. I can see the unending mess of fine grinding dust and swarf when flooding it with thin oil to attempt cleaning without disassembly.

cheers mate, good info

I have found that most Chinese made lathe and milling tools need deburring.

I just bought a 4” three jaw Vevor for my rotary welding positioner. You don’t need a great chuck for that. What people have to understand is that it’s just amazing that they can make equipment for these prices. But in understanding that, you also have to realize that they have to save money where they can. So an extra cleaning cycle and deburring parts that don’t affect the function are not done. Sometimes, I find some burrs on parts that shouldn’t have them. Overall, everything that is cheap should be taken apart, cleaned and deburred, if necessary. Just think of that as your part of the savings. One guy recently bought a Vevor 10” 4 jaw chuck for $125. Through the entire process of taking it apart, cleaning and deburring it, he was giggling and complaining that it wasn’t made like a more expensive product. Some people don’t get it and just think that complaining about cheap Chinese (or Indian, now) products makes them seem as though they know more than they obviously do. My little 4” chuck was also tight when the jaws got to the center. Some deburring with a small diamond file fixed the problem. Here, he understands that it’s to be expected, and he fixes it without the nonsense complaiming I see in too many other channels.

I find their equipment not to bad for the price. My last chuck worked fine but they are not top of the range. that will cost 6 to 10 time the price. I have had top brand goods that have been so bad and after service non existent that I now refuse to pay for a brand name.