Actually with that reply (thank you) I should say that the part I was unable to chuck is 5" diameter because my larger 6" chuck jaws dont reverse.
Old Fart or not, I have not actually seen EVERYTHING, but one thing I have not
yet seen is a 4-J *independent* chuck whose jaws were NOT reversible.
Simple sort of "half nuts" bearing against a modified Acme screw, it doesn't give a damn which end goes in first, annnnnd
"Oh.. BTW." amongst the reason some OF's have never seen the need of owning even ONE of the weak-ass-grip THREE jaw chuck tribe, is that not ALL jaws on a 4-J have to "be there", nor even point the SAME direction if they are there.
Seriously. A 4-J can hold some insanely complex shapes. So can a fixtured-up faceplate.
I can only wish my 6-Jaw was "independent" instead of scroll-operated!
I figured 8" since it is a 10" lathe why not have some head room. The jaws could stick out up to almost 1" and accommodate up to about an 8" part. That was my reasoning.
U got me thinking on a 6" reversible jaw option.
Yah well. about that one-inch..
The OEM 3-J (2 pc jaws) French-made "Handy" of the metric equivalent of 8" on the Cazeneuve hit the damn sliding cover at not a lot more than that, threatened the nice dovetail at the front edge of the cross, and that, dear hearts is not on a 10" lathe. An HBX-360 is a nominal 14" with an actual just the metrfuckated skosh under SIXTEEN inch swing.
It has been gifted a pair of 7 1/4" 4-J. Comes out even when metrifuckated, but I don't recall at what. HBX is kinda bisexual, so I leave the damn conversions to the machinery. I have less than zero use for a 3-J scroll-operated "self OFF centering" anyway.
"nuther thing...
Don't confuse "reversible" on a scroll chuck, which USUALLy wants separate jaws because double cutting to fit the scroll (yah, some fools DO that..) makes them as weak as kittens.
With .....screw-operated, where jaws are inherently reversible, as above.
OR with TWO piece or master/top jaws which make most sense on 2-Jaw - because they are nearly ALWAYS going to be custom-machined to hold a specific item, bi-laterally symmetrical only maybe, round very damned seldom....
OR 6-jaw where 12 fasteners are a pain in the arse, but cranking 6 jaws out and swapping them for the other SET. if not yet lost. strayed, stolen, is a BIGGER pain.
3-jaw is worth 2-piece for soft-jaw/pie jaw, similar custom tooling to a 2-J, just different about release for 3-segment "parting line" than a two-segment 2-J.
Otherwise, two 3-J, one set each way and left that way are cheaper as well as faster.
That's part of why I have more 6" 4-J that the average Bear, BTW.
Pop one off the D1-3 that has it jaws one direction and LEFT that way, pop one on the D1-3 as has its jaws the
other direction and LEFT that way....
...and I don't have to spend the time cranking 4-jaws out turning them around, then cranking them back in.
I did that once. A long time ago. About fifty years I think it was?
WTF
new lore am I going to learn from doing it a
second time when a second chuck will easily serve fifty years if not abused?
MY curse? Simple enough. I was NEVER a "hobbyist" until I got older than dirt and was handed 20/15 bionic vision. Wuddnya know it? No longer blind, I could SEE pretty wimmin' but too damned late - couldn't remember why I was supposed to care!
"Old Iron" on the other hand? Now THAT I could still play with - if only 'coz it couldn't
run fast enough to escape my greedy hands!
Mentally, I buy tooling as if still running the manufacturing operation where I was going to have to PAY an operator Union Scale - or even more-yet when NOT Union - and I don't want him wasting that fully-burdened TIME. No shop I ever ran had to beg for tooling - it was always there before my team even knew they needed it. Manager's JOB to see to that ahead of time. That's a major part of why I was always profitable.
It isn't as expensive a bad habit for a hobbyist, either. Yah only get but the one life. Why waste the hours of it ...and still be short of money, anyway?
Yes right now there is only budget for one chuck for now.
Buy a brand-new Chinese "San Ou" or Taiwanese "Vertex" then. The ones with THEIR OWN brand-name (and max RPM) right on them.
No no-names. Ever. Too damned many of the no-names are factory QC rejects, They weren't going to just shove them up their ass and keep on doing that, were they? Sold-off to "remaindermen", rather - same as last month's funny-papers or condoms used but the one time.
Shars backplates are OK, but that's as far as it goes. Dice-roll after that, some good some not-so-much.
Brand-new chuck at least won't be wore out, have been in a fire, have internal cracks 'coz it was dropped four stories, etc.
Those two brands ain't actually ain't half bad. San Ou has even been striving to be seen as GOOD, yet is still cheap.
Vertex Taiwan may of may not be - they built a daughter factory on the mainland several years back, supposedy kept only the higher-profit CNC goods in the Taiwan plant, but at least the experience and QC should be the same.
Your goal is to get up and running with the promise to yerself
any "El Cheapo" will become a secondary-use tooling in the fullness of time.
The one with the jaws always bass-ackwards, for example.
What's a GOOD 4-J?
Well.. My medium-width-jaw forged steel Swedish SCA's are stronger than my elegant but slender high-RPM forged-steel Polish NOS "old Bison", but my OLDER Skewl yet NOS forged-steel Yuasa is the Godzilla jawed heavy-cruncher when I really, really need a trusted GRIP. The 5" and under - down to the - $90 was it? San Ou 80 mm are Semi-Steel or Grey iron.
Nearly all the "Grand Old" chuck makers simply QUIT making manual chucks of any kind under ten inch or larger sizes a long time ago and/or sold-on their brand-name. Even Bison ain't always Bison. See Toolmex.
All the MONEY is in chucks that get wore out faster and are worth serious coin for a factory rebuild.
Read: BIG ones, "oilfield", even. Or POWER operated chucks on a brazillion hard-working 24 hr, X 5, 6, or 7 days a week CNC spindles or some combination thereof. Go price a 20" chuck, a Kitegawa, Samchully, SMT, or Schunk. You'll "get it". They all followed the money.
AND NOT a "manual" operated chuck that won't need a replacement for another 70 - 90 years on some hobbyist's personal lathe.
There's yer problem. Motor car and tires yah can sell and keep selling.
Drager tire guage I bought in 1968 still works as-new, will surely outlive ME.
Wasn't for SCUBA divers drowning their ass now and then, body not recovered, Drager wouldn't have a market. Some stuff just lasts too long for the maker to earn a crust.