Limitation in self centering jaw chuck

[Ken from ontario]

@Alberto-sp, One thing you need to consider is the size of the motor on your mini lathe,, if it comes with a brushless motor ,it can (barely) handle a 5" chuck but that same 5" chuck would be too heavy for the " classic" mini lathes . I have a 5 " four jaw independent chuck and can tell you it is the maximum weight /size I'll ever use on my lathe even though the motor on mine is the more powerful brushless type but you can still hear it laboring on the initial start , it also takes twice as long to stop .

https://littlemachineshop.com/products/product_view.php?ProductID=2345&category=

 

[woodchucker]

guys, the 5" and 6" was my example of the 3 and 4 jaw for MY SB9. I was explaining that generally they are different.
We need to figure out his lathe and available options.

I can't believe how sideways his simple question went multiple times.

 

[NC Rick]

Sorry for ruining the thread! It seemed likely to me that if the lathe would swing a wide open 4” (that close to 100 mm) then a 5 or 6 inch chuck may well work. Dimensions and inertial limitations seem like would be more obvious to the lath owner.
please accept my apologies and I’m out.

 

[Ken from ontario]

Sorry for ruining the thread! It seemed likely to me that if the lathe would swing a wide open 4” (that close to 100 mm) then a 5 or 6 inch chuck may well work. Dimensions and inertial limitations seem like would be more obvious to the lath owner.
please accept my apologies and I’m out.

I am confused, I don't know why "you're out" , I re-read (and liked) all your posts here, please let us know who you think is upset and why , the main point you made was that we still need to know more info about the mini lathe and what the OP is actually searching for.

 

[epanzella]

Learn to love your 4 jaw!

 

[brino]

I can't believe how sideways his simple question went multiple times.

What? Where?
(meant with NO reverence to Vinny Barbarino!)

Okay, perhaps a small reference to needing a few dozen different chucks minimum, but I took it as a joke....
It was followed with a "Lol"....but maybe that doesn't translate well....

Sorry for ruining the thread!
please accept my apologies and I’m out.

No harm, no foul!
Rick I see no reason for you to apologize, please stay and help!

I think we need more info from the OP to fully understand the situation.

Brian

 

[woodchucker]

I thought you guys were stuck on the 5 and 6 because I mentioned my SB using 5 and 6.
I immediately saw responses to that effect, also the recommending many chucks.
I just didn't think we were trying to help in in an efficient manner. We know nothing about his chuck, his mount, his measurements from center.

Sorry, I just thought it went off the rails.

 

[brino]

I believe we are all-good here guys!
I just would like to avoid any misunderstandings or finger pointing.

We can wait for some more input from the originator.
Some pictures of the existing chuck mount and some diameter measurements would help a lot.

@Alberto-sp No worries about your english ..... please feel free to post and ask anything you want!
Just know that we are a passionate group dealing with technical details, so we will be asking some questions too....

Brian

 

[Alberto-sp]

Thanks for all your answers.

I´m still learning english so I sometimes have problems to explain myself. These are my chucks. 100mm diameter



I don´t mind 3 or 4 jaws. The 4 jaws is non self center, but its aperture is much bigger than the 3 jaws wich is self centering. I could use the external jaws, but the grip surface (Blue line) is much less.

So, what I want is a self centering (3 or 4 jaws) chuck with the aperture of the left one.

This is a pic of the backplate (100mm diameter) I posted it here some time ago (When I asked for the 4 jaw chuck)



And this is the specs of my lathe



Thank you

 

[NC Rick]

I feel like it is worthwhile to bounce around ideas. I was aware of the things we don’t know about our friend Alberto’s lathe. I don’t have answers and hoped I might be offering another set of things to think of. I have never owned a mini-lathe so I’m pretty under experienced, the small lathe I upgraded from was a Rockwell 10”. Maybe I was being over sensitive but I felt like Woodchucker was complaining of me derailing the thread with non-valid suggestions without reading all the information (something I am fairly likely to do). Thanks for clarifying folks.

Alberto, while most are pretty hard, it is possible to bore out the body ID on many chucks using carbide tooling. It would be necessary to disassemble your chuck and make your own judgment of how much you can get away with. A ridged setup and strong carbide tool is needed to deal with the highly interrupted cut.

I think most of us get into situations where we are wishing to extend the capability of our equipment and ourselves. these situations lead to learning and sometimes (many times for me) mistakes where I learn how NOT to do things. I don’t know your application but don’t forget about the possibility of building some kind of fixture on a faceplate.

i may well have been feeling a little snippy yesterday. My wife and I both have Covid and both have been fully vaccinated and boosted. We run a business from home with employees and there are some frustration and problems in making things work. I’m essentially locked out of my shop which is enough to **** off anyone!