Robin Rinzetti recently put up a YouTube on how he trues up Lathe chuck jaws that I found very informative. As always, he explains it all very well.
Pete
Robin Rinzetti recently put up a YouTube on how he trues up Lathe chuck jaws that I found very informative. As always, he explains it all very well.
Pete
Grind them..and always use the same place on the chuck to tighten the chuck. Of course this is only on a live chuck. Independent chuck doesn't matter unless you're worried about it making up the part it's chucked onto. In that case, indicate a say 1.250 part into the very back of the jaws and dress the jaws for that diameter part...but I don't do that and I imagine it might be tough to indicate the part at the rear most of the jaws. I guess you could machine a part from a single setup, turn the od and bore the id, as well as indicate both a close as possible...then indicate on the id to dress the jaws.
Last edited by mwezell; 12-01-2022 at 07:55 PM.
Maybe this one: https://www.youtube.com/watch?v=jhreM8WK4zE . He's usually pretty over-the-top.
GsT
I finally got around to watching it. What surprised me most was seeing a Shars indicator! (He probably rebuilt it and replaced the sapphire bearings with PCD coated titanium or something, and I just missed that video...) This one actually seemed within reach of mere mortals.
GsT
Yes. Many times it boils down to what the tool is used for. I use a lot of cheapo calipers and have had good luck with them, FOR WHAT I USE THEM FOR. Calipers are not and were never intended to be a precision measuring device. If you want that, use a high quality micrometer. Cheap digital calipers are generally very acceptable anywhere I'd trust even the best set of calipers but that's just the wrong tool for the job if you want a truly accurate measurement of something. Oh and resolution has absolutely zero to do with precision. Just because a set of calipers(even good ones) may read five places behind the decimal doesn't mean it actually accurate to three.
Same with my previous post on this thread. The method I described has been a proven method for truing chuck jaws up that's been good enough for most any work we'll see for a really long time. But yes, I do think he has a good point about the jaws and the moment where they pivot under tension. It's just likely overkill for just about anything practical. That doesn't mean he's wrong though. I've got a couple of old chucks that I no longer use laying around. They're just laying around for a reason. At some point, it makes sense to bite the bullet and replace worn out stuff. One is so worn that I don't think even this method will help it...at least not with me having any faith in it. I used it recently for a rusty piece of cast that needed to be turned down and it wasn't a critical job. Worked fine for that but that's about it.
Last edited by mwezell; 12-03-2022 at 06:18 PM.