|Forum topic by Picken5||posted 87 days ago||441 views||0 times favorited||5 replies|
87 days ago
Well, I think my Delta 46-700 lathe may be on its last leg – but I’m hoping someone out there in Lumberjock-land can offer a helpful tip or suggestion. Yesterday, I was turning a small block of walnut. I decided it needed a 3/8” hole in the middle of it, so I shut down the lathe, inserted my drill chuck into the tailstock, chucked up a 3/8” bit, lowered my face shield, and turned the lathe back on. I started advancing the drill bit into the work and, after it was about a half-inch in, the entire drill chuck started turning and I realized I had forgotten to lock down the quill on the tailstock. I quickly shut down the lathe but it was too late. The quill totally unscrewed itself from the tailstock. It was an interesting sight, I must confess, to see a block of walnut attached to the headstock of the lathe, with a 3/8” drill bit sticking out of it – and the bit’s still in the drill chuck, and the drill chuck is still in the quill. Quite an arrangement sticking out of a block of walnut. But the quill was no longer in the tailstock. Crap!
I thought I’d just be able to re-screw the quill back into the tailstock. But it wouldn’t go. I took the wheel off the back of the tailstock and removed the bolt that screws into the quill so I could examine it more closely. Looked fine except for what appeared to be a minor burr near the end of it. So I carefully filed that off and tried again. Keep in mind that this end of the bolt has a left-hand thread – as does the mating hole in the quill. (Not sure what the size or thread is, but it appears to be 9/16-14 – left-handed.) And, of course, the bolt has a hole drilled down its length for a knock-out bar. Well, the bolt went in about 1-1/2 rotations before it started binding. I took it apart and inspected everything again. The threads inside the quill appear to be fine – as do the rest of the threads on the bolt. But it simply won’t go back together. I thought about running the right size tap down the quill to clean up any threads I couldn’t see very well – and doing the same with the right size die on the bolt, but coming up with left-handed taps and dies isn’t easy. Fastenal offered to special order them for me, but it would take a while and cost a fortune – and I’m not even sure I’ve guessed the size correctly. I can order a new quill from Delta, but it’ll be 60 days or more before I get it, and the bolt is simply out of production. (I’ve attached a photo of the quill and bolt in case it’s useful. The longer end of the bolt is what’s supposed to thread into the quill.)
I suspected the bolt may be slightly bent, but after carefully checking that, I’ve ruled that out. Since it’s basically hollow, it occurred to me it could be twisted just enough to make the threads not work. But I’ve got no way to check that. I may have to find a machine shop to make me a new bolt for the quill, but I have no idea what that’ll cost.
I may be in the market for a new lathe — but that’s not my first choice. I’d rather fix this one. Anyone got any ideas?
-- Howard - "A bad day in the workshop is still better than a good day at the office."