Boxford lathe

This probably applies to many lathes. I've just bought a very old circa
early 1960s Boxford 4.5" AUD. The circumstances and price of sale didn't
allow me to examine the machine in detail, and I now find that the fitted 3
jaw chuck is well and truly stuck to the mandrel nose. Have tried the lathe
in locked backgear with a bar through the chuck jaws, but the torque applied
(without success) makes me fear for the backgear teeth. Are there any other
tips that are tried and tested, e.g.. heat, other ways of locking the
mandrel etc. Does anyone have any idea of a safe torque to apply before
damage to the mandrel itself. I believe if everything fails I could turn
the chuck backplate away from the mandrel. has anyone done this, and has
any tips to minimise risk to the mandrel threads and register.
Regards Dave
Reply to
Dave
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last hope is to machine the chuck off
but I would try some penetrant oil { KROIL]
some very light heating [ in the 120-150 range]
more penetrating oil
work at over or the course of a few weeks
Reply to
williamhenry
Not nice really, but this worked for me: Got some big hex bar, tightened in the chuck. Used a ring spanner as a flogging spanner, with a big hammer. No backgear, just inertia and the shock brought it loose.
Jordan
Dave wrote:
Reply to
Jordan
To add to this method, take the chuck off of the backplate first, the chuck has a huge amount of inertia compared to an empty backplate. Then, bolting the bar to the backplate and smacking the end of the bar has a greatly increased chance to crack it loose. Even if you just put a couple of bolts in the backplate and wedge the bar into those bolts, it can work. I had a larger OLD, really old lathe that it took weeks of soaking, and prying with no success. Putting a bar into the lathe jaws and prying the end of the bar yielded no success. Finally taking the chuck off, (it was a 14" chuck) to eliminate the inertia of the chuck, and it popped loose from a crack on the end of the bar. Besides, you REALLY don't want to smack sideways on the same chuck jaws you want to use later anyway. Breaking a back gear tooth is real possibility if the backplate is stuck bad enough. The inertial breaking method with a BFH avoids that danger. Pete
Reply to
3t3d
The same happened to my Boxford a few years ago when a roof leak left unattended rusted the headstock and chuck over the space of a couple of months. Lots of heat and penetrating fluid over many days just didn't work - So I ended up sawing a notch in the backplate 95% of the way to the thread and using a small cold chisel to crack the backplate - a new backplate was only a few pounds although quite a bit more than the equivalent Myford one - have a look at the adverts in one of the model engineering mags, one of the companies does secondhand and new alternative Boxford bits (can't recall who though) Boxford can still supply parts if you are stuck - they're really expensive though!
I also bought some new headstock bearings as well just to make sure all was well - although it was far from simple to fit the chuck end headstock bearing inner race. Bugger up the mandrel nose and you are looking at (I think) 2-300 quid for a new one :-(
Reply to
Martin Evans
Thanks for the replies.
Will try slight heat and more fluid and manufacture something to screw to the backplate with the chuck body off, and try the BFH approach, but gently. I have seen backplates as cheap as £10, it's not the cost of the backplate that worries me, it's my ability to machine it away without damage to the expensive mandrel. I'm not too happy at trying to split the backplate with a chisel as I believe the Boxford front bearing is a roller which don't take shock loads like a big plain bush.
Thanks again
Dave
Reply to
Dave
I like to take the long view on this sort of thing and figure that's going to take a few days. Keep spraying the affected area with liquid wrench and keep gently tapping it for a few minutes every so often. This seems to encourage penetration. I dunno...usually problems I've run into like this have responded to being slowly chipped away. When I've tried to do it "right now" something winds up broken. Can you take the chuck apart? I'd try clamping something in the chuck, spraying and tapping, then loosening it up. Over time, a little heat, lots of spray lube, loosening and tightening, tapping will often work. Try to stretch it all out. Hope this makes sense...
Chas Morrill
Reply to
Charles Morrill

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