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Lathe questions
Posted: Sat Dec 22, 2007 12:31 pm
by Alley Kat
Locally there's a lathe for sale, and cheap; described as 'old American, large, good order'. Now I know feck-all about lathes except that having one would be dead good.
So basic questions: will it need specific, proprietary tools & bits, or will I be able to buy chucks or whatever that will work/fit with it?
I've no idea what to look out for particularly except obvious feel for play and roughness in moving parts.
Any thoughts appreciated gents,
cheers.
Posted: Sat Dec 22, 2007 12:44 pm
by 5000SE
Whith that kind of machinery, large tends to mean cheap - and can mean scrap value, becuase there's no market. Small stuff, ike toolmakers' lathes, can be expensive because everybody wants one and can fit in in their shed/garage.
You can get just about everything for any lathe, and most cities have used machinery shops - I use one in Sheffield and buy chucks and tools for peanuts.
Posted: Sat Dec 22, 2007 12:59 pm
by Alley Kat
Excellent, thanks for that, it sounds worth checking out at least. Cheers.
Posted: Sat Dec 22, 2007 1:24 pm
by ian.stewart
Chucks, Main 3 jaw chuck is or should be specific to the lathe and the bore of the chuck ground to suit, Tailstock chucks will be easy to get, depends on how big a lathe normally dictates the size of the Morse taper in the tailstock,
What make is the lathe? south bend??
the 2 main things to watch for is how complete is it, an a minimum you MUST have is a 3 jaw chuck, Tail Stock, and tool post. if either of these is missing walk away, things like a steady is nice especially on a bigger lathe, things you would like to have also would be a quick change tool post, 4 jaw chuck, Face plate, Running centre, Draw bar and collets and quite a bit more, changable tipped tools and suds pump are also worth having,
the other thing to watch for is RUST, its very often with disused machinery that its dumped outside and left to go rusty,its a precision ground piece of kit, and rust removes the hardened ground surface of the bed, Beds do wear, normally around the chuck area, and also dependant on what has been turned on a regular basis, machining Cast Iron is a killer Most if not all the slides will have a method of adjustment with a flat slide adusting onto the underside of a "dovetail"
Depending on the age of the lathe you may need to use drop gears for screw cutting if this is the case the gears will be kept either in the end cover or in one of the legs, just make sure they are all there, but normally the lathe will have a screwcutting box and the drop gears should be only used for cutting oddballs.
Another problem with bigger lathes is they are 3 phase, a Inverter will work but you only get about a 3rd of the power, and I think a loss of speed as well, you will need at least 1/3rd HP single phase motor, and TBH get an older used one, the modern motors do not seem to have the torque to do the job
Posted: Sat Dec 22, 2007 1:33 pm
by Alley Kat
Fantastic, thanks for that Ian, much appreciated...
No idea what make yet, or what there is/whats missing, didn't want to phone & take the guy's time without some sort of background info. Thats a big help there, cheers.
Posted: Sat Dec 22, 2007 2:59 pm
by Eliot
remember, once you have said lathe - you need to learn how to select the correct tool for the job and be able to grind them too.
I inherited my late fathers entire workshop - so i'm slowly self teaching myself, but its a slow process. I have masses of tools, so I just have to try each one and study how it was made / sharpened - sometimes very frustrating, but its extreemley rewarding when you actually produce something on it!
Ive been working on a gearbox adapter for the last few months(!)
http://www.mez.co.uk/4l80e-1.html
Its pushing the little colchester student to the limit.
Posted: Sat Dec 22, 2007 3:08 pm
by Alley Kat
Thanks for that, I'm expecting a slow learning process, hopefully without too many flying chunks...
Gbox thing looks interesting, fancy adapting a Supra box to a Lexus? LOL
Posted: Sat Dec 22, 2007 3:13 pm
by ian.stewart
Im not too far away if either of you get stuck, generally I stay ayay from tool grinding except for special jobs, I tend to use replacable Ceramic/carbide tipped tools, they last a long time if they are not abused and can be found on Fleabay for pennies.
Posted: Sat Dec 22, 2007 4:19 pm
by Alley Kat
Thanks mate, appreciated

Posted: Sat Dec 22, 2007 5:33 pm
by kev_the_mole
Ask the seller the name of the manufacturer. Most American large lathes are going to be 50/60's vintage. Not necessarily bad but big and clunky. I started out on a 'lend-lease' Warner and Swasey circa 1943 (the lathe not me).
Cheers,
Ian
PS throttle bodies not forgotten but we're out to seven weeks lead time at the moment and 'homers' are verboten

Posted: Sat Dec 22, 2007 7:47 pm
by Alley Kat
Thanks Ian, if it's big n clunky me & it'll get along fine
Gonna try & see it next day or two. Maybe another goodie from Santa along with my tube bender : )
Posted: Sun Dec 23, 2007 8:18 am
by kiwicar
Hi Alley Kat
Hope this may be of interest, I have "Model engineers handbook" ISBN 085242 715 8 it is written for people who build steem engines, however that is at most a fifth of the book, what it contains is alot of information on screw cutting, how to grind tools for cutting different metals, the correct height to mount them, how to find center height, stuff on morse tapers, correct speeds to use when machiening and some basic stuff on lathe set up.
Mike
Posted: Sun Dec 23, 2007 10:03 am
by Alley Kat
Sounds good Mike, thanks for that. A book recommend would've been the next question
cheers
Bill
Posted: Sun Dec 23, 2007 10:24 am
by Alley Kat
Rang the guy, it's too big, over 6 foot long. Sounds fine otherwise but just haven't quite got that space at the mo. The search continues though.
Posted: Sun Dec 23, 2007 10:34 am
by Paul B
Alley Kat wrote:Rang the guy, it's too big, over 6 foot long. Sounds fine otherwise but just haven't quite got that space at the mo. The search continues though.
Any lathe bigger than a toy makers lathe will be over 6' long.
I'd like one myself, but if I get one it'll have to be big enough to swing a flywheel, disc brake or drum, else it is not really worth the effort to get it installed and fixed up.