My replacement spindle arrived a little earlier. In typical Grizzly fashion the oily spindle had been draped in a layer of flat plastic and tossed in a cardboard box, along with a plastic cap that fit over the threads so loosely that it falls off from gravity. The spindle parted company with box, plastic sheeting and end cap probably before it left Missouri. The threads are .015" smaller than my old threads at 1.20" OD. A few nicks and dings and some thread damage on the handwheel end bear evidence my spindle bounced around in the back of a UPS truck without any protection at all. May have to touch up the threads a little but no big deal and assuming this beast ain't bent it survived the journey. I did tell the driver to make a note and took photographs. Slid the spindle out of the existing hole in the box with no problem and showed it too the driver. (end of part one, going to try to get part two in the next post, same thread)
(part 2) I reversed the faceplate and threaded it full depth and a bit more and gave it the rattle test on my old spindle nose and the new one. The fit was slightly better on the new spindle. This is a replacement for a damaged or defective spindle, not a new generation upgrade. With the amount of slack when threading on the new spindle I don't think it is possible for there to be 75% contact or anything close to that. It still rattles with full thread engagement. Those with issues need to get a new spindle. Those without issues don't need to bother trying to get a spindle that may be no better or worse than the one you have. This is a replacement part, not an upgrade for spindles that didn't have unusual issues or a new generation spindle. Hu
Hu, Thanks for posting the info, although disappointing. Even with my current undersized G0766 spindle(s), when the chuck or faceplate tightens against the register, I get a lock-up and it is not possible to feel any looseness. I have also done this this a dial indicator. So I'm wondering if you are referring to looseness prior to lock-up/final tightening or looseness once the chuck/faceplate is tight against the spindle register? On mine, I filed down the 0.010 oversized shoulder because it was not allowing my Grizzly chuck from seating against the register. I presume that you - - like hundreds of other owners - - have filed down that shoulder on your old spindle?? I'm wondering if the new spindle shoulder is still 0.010 too large and still interferes with proper tightening of chucks and faceplates. Just wondering....
Brice, One of the old school rules, always modify the cheaper component. I opened up the insert on my chuck instead of cutting on the spindle. What I am doing is threading the grizzly faceplate on the spindle nose with it reversed so the face is towards the headstock. That lets me get full thread engagement on the faceplate with spindle threads either side of the faceplate. This gives maximum thread contact without any face or boss supporting the threads. With about an inch of threads engaged there should be very little movement. While there is slightly less than my battered threads there still is significant play. This means that when you jam the faceplate against the face of the spindle only a few threads are taking most of the load instead of it being distributed throughout the threads. I like the new spindle better than the old one but mostly only because of getting rid of the stress risers and potential future issues. Hu
My new spindle arrived today. The finish looks good. Here is a summary of what I measured: 1. Major Diameter = 1.219". Spec (Cl 2A) is 1.2329-1.2479. It is out of spec (too small) by 0.014" 2. Pitch diameter (3-wire method and w. thread mic) = 1.164" (spec is 1.1597-1.1667) - OK. 3. Diameter of shoulder at base of spindle = 1.258" --this is oversize for many after market chucks and will need to be filed off by the user 4. Profile of thread - - The threads look nice (not jagged and razor sharp as before) but are a little stubby and have less engagement than Grizzly told me to expect. Crest width should be 0.125 * Pitch but measures 0.25 * Pitch (this is the result of the under sized major diameter - - they should have left more material). The root was measured at 0.22 P - - fairly close to the nominal 0.25 * P. 5. Through hole diameter - Grizzly specs this at 0.393" which is works for some vacuum systems. A 3/8" drill gets stuck midway through.
I have mixed feelings about the new G0766 spindle. The Grizzly manufacturer has made it look nicer. But they seem to be stubbornly resisting correctly three "no-brainers" - - that is things that wouldn't cost a dime more to produce right and which - - if fixed - - would tend to elevate the perceived quality of the unit. The three items are (1) under-sized/under-spec spindle major OD, (2) Over-sized shoulder and (3) through-hole alignment doesn't meet Griz's published specs. As Hu posted - - the major OD has been reduced further out-of-spec. Surprising - - since it is so easy to measure and was commonly known as an issue. So, when I change out my spindle, I'll need to file down the shoulder and I'll try to run a file or burr or something through the spindle to open it up a little for my vacuum chuck. This is probably as good as it is going to get with this class and price-point of this lathe model.
