If you buy the collets on eBay and you measure them, if they are out of spec you can return them as "not as described" and then seller is obligated to pay for the return postage. You will get a prepaid shipping label. Many times sellers don't want to pay to return ship a bad part, after all what would they do with it? So they jut resend a replacement. It's a hassle to have to wait twice for you order but the up side is you might find a use for th defective parts they let you keep.
I have four parts being replaced to me right now, One is a precision 8mm stainless bar that has rider marks on it and a linear recirculating ball bearing set that ha loose ball in the package. They are seeing replacements. eBay is very safe this way. If the seller does not handle the problem eBay can reverse the transaction and pull money out of the sellers account. So buy the Chinese part but make sure there is a spec on the web page and measure it after you unpack it Most of the stuff is very good, better then spec'd But I did just get some defective parts On Sun, Jan 14, 2018 at 11:44 AM, Les Newell <[email protected]> wrote: > I bought some Chinese BT30 and BT40 ER32 collet chucks off eBay a while > back and was pleasantly surprised by how accurate they were. The finish > looked good on all surfaces. I bought one before buying the rest and > measured the bore when fitted in the spindle. My tenths dial gauge hardly > moved. When I got the rest they were all pretty close. The nuts on the BT30 > chucks are a pain though. The bit that locates in the groove on the collet > is concentric instead of being offset. This makes it a real pain to get the > collets back out. Those ones are for my router and will spend most of their > lives with 1/2" collets so I'm not that concerned. > > Les > > >> There are a few reviews of Chinese collet chucks on youtube. The two >> I've seen measure chuck internal taper runout similar to your >> experience, Gene. (The outside's OK, but the bit that counts is poor.) >> Once one of the Chinese collets is inserted, all bets are off, and it's >> best for woodworking. >> >> One review showed one of the ostensibly ER32 collets in the set was over >> 33mm in diameter, and couldn't be inserted in the nut in half a minute >> of wrestling. >> >> Another video shows a Chinese collet chuck's internal taper being >> ground. Nowhere have I seen anyone use one as-is. >> >> It appears to be best to remember how _much_ cheaper they are, and then >> consider why. I wouldn't buy 'em, except as a kit to grind to tolerance, >> chucking out the collets beyond rescue. >> >> To attempt a rescue, maybe skim the chuck internal taper, then hone it? >> The chances of making it worse are slim. If it works well, there's a >> very handy youtube video in it. >> >> Erik >> > > > ------------------------------------------------------------ > ------------------ > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > -- Chris Albertson Redondo Beach, California ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
