Best topic for cleaning, adjusting chucks?

[mikey]

However, when I chuck a larger piece up the runout increases. I am just wondering if a guy was to tumble/ micro polish all parts if this would be beneficial or could lead to other problems or be a wasted procedure.

Tom, this is normal for a 3 jaw. Anytime you move to a different part of the scroll run out will change. Just the nature of the beast.

As for polishing the parts, it will make it feel smoother in use but it won't change the character of the chuck. As the chuck wears in, it will get smoother anyway so I wouldn't bother polishing anything.

 

[Nogoingback]

Even if polishing improves smoothness, I don't understand how that would improve runout. If you need better runout than what
you're getting you need a 4-jaw, or collets.

 

[Tom1948]

Thanks guys. I am still learning about things and I value your opinions. It was just a thought and after all, isn't that what this forums is about, sharing knowledge.

 

[DavidR8]

Thanks guys. I am still learning about things and I value your opinions. It was just a thought and after all, isn't that what this forums is about, sharing knowledge.

Absolutely! No harm in any suggestion.

 

[mikey]

I wonder if the op saw this YouTube vid on winkey's workshop? It talks about chuck weight and overhang.

Hey John, what are your thoughts on this? I watched the video and his conclusions seem to indicate that overhang is the culprit; this may be true for his particular lathe but is it applicable to other lathes?

I have a Emco Super 11 lathe and own 6 jawed chucks for it, one of which approaches about 35# in weight. They vary in size, height and weight but I can part without issue with all of them. My spindle is a little over 2" OD, with a D1-4 camlock mount. The spindle runs in P6 bearings, which are just an okay accuracy class but it has zero run out. I can part with P-type blades and up to 1/8" inserted carbide parting tools and have zero issues parting any material I commonly work with, regardless of the chuck I happen to be using so ... hmmmm.

I also happen to have a little Sherline lathe that uses a rear mounted parting tool that will easily part stuff up to 2" OD at high speeds and it has a spindle that is all of 3/4" OD. I've parted stuff hanging out of a Beall ER-32 chuck that itself is hanging out nearly 4" from the spindle; the work is out beyond that and I've had zero issues parting with this chuck.

I raise this simply to caution you that when reaching conclusions about a complex operation, things are rarely attributable to a single cause. I'm not disputing his conclusions because they may apply to his lathe in the condition that it is in. I am disputing that it applies to all lathes because there is evidence to the contrary.

 

[John TV]

Mikey, not sure I have the chops to have any contributing thoughts about winkeys vid. I watched it mostly because the two lathes I have are both Logan and he is using an 820 like one of mine.

It seems to me the added weight or length would only factor in ( within reason) if there is some wear in the bearings. Or if the original specs are loose enough to allow for more sag. I realize everything moves but I'm thinking wear might be winkeys issue. Just a thought.



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[mikey]

I may not have the chops either but the same thought occurred to me - spindle might not be so good; bearings, preload or something like that. I don't have a Logan, nor have I run one on TV, but from what I understand they are capable lathes and just a chuck hanging out a bit more shouldn't prevent them from parting. There is more to this than meets the eye.

 

[tmenyc]

Mikey et al, thanks for your helpful advice and info. The chuck itself is fine, but the jaws were layered with primordial gunk and were the problem. The jaws have had a good soak in superclean, are much cleaner, ready for reinstall.
Thanks again. So much to learn...
Tim

 

[Nogoingback]

Mikey, not sure I have the chops to have any contributing thoughts about winkeys vid. I watched it mostly because the two lathes I have are both Logan and he is using an 820 like one of mine.

It seems to me the added weight or length would only factor in ( within reason) if there is some wear in the bearings. Or if the original specs are loose enough to allow for more sag. I realize everything moves but I'm thinking wear might be winkeys issue. Just a thought.



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The FAQ on Logan's website has a section on chuck size which indicates that oversize or heavy chucks can have an adverse effect on the spindle and bearings.

 

[mikey]

The FAQ on Logan's website has a section on chuck size which indicates that oversize or heavy chucks can have an adverse effect on the spindle and bearings.

Here is the quote:
What is the right size chuck for this lathe?
2.13.. Logan supplied a 5” 3-jaw chuck and a 6” 4-jaw chuck for their 10” lathes. Logan supplied a 6” 3-jaw chuck and a 6” 4-jaw chuck for their 11” lathes. Larger chucks were available, but they are impractical on these lathes because the jaws would hit the bed when the chucks were opened. Larger chucks are also heavier, so they put a strain on the spindle and spindle bearings. In general, use the smallest possible quality chuck for the job.

I think we can all agree that Logan's advice is wise. However, it does not jive with what the video guy is saying. He was using chucks of the same diameter; its just that one was longer (and of course, heavier) and he says that the longer chuck causes parting issues. I think this is nonsense. If he had said that "my lathe cannot handle the inertial effects of a heavier chuck so it is likely that my spindle bearings are worn" then I would buy that, but that is not the conclusion he drew.

Perhaps the lesson here, for all of us, is to think things through before swallowing something as fact. That especially includes anything I say.