View Full Version : A Question for Chief

07-24-2003, 08:35 PM
Hi chief. Got a dumb a _ _ question for ya. When they set up a lathe on a ship, what steps do they take to level it out? Yea, I know dumber than dumb, but I was a corpsman, so what do you expect! http://bbs.homeshopmachinist.net//biggrin.gif

John B

07-24-2003, 09:33 PM
The only dumb questions are the one's you didn't ask.
The lathe sits on pads welded to the deck which were installed when the ship was in drydock.The lathe is leveled by jack bolts threaded into the pads with shims inserted as necessary for fine tuning. The old 12 inch level at each of the axis is the method used and then a test bar is cut and measured.
HM's I spent many hours in the company of
MANY FINE CORPSMEN treating various social
and tropical dieases I managed to aquire along the way.
To avoid have some unsavory aspects of my medical history or indiscretions put in my record I would make the corpsman fancy brass
or polished aluminum handles for their operating tables or fittings the their passageways .

07-24-2003, 11:02 PM
Wait a minute here! Once worked with a guy that was in the Navy. He did machinist type work on a ship while fighting the war with Korea. He said that you could see the lathe ways bend and twist when the sea got too rough, could not run lathe above certain limit of wave height. How would a lathe stay aligned after a beating like that. Lathe was around 14" X 30-40' bed. He said that he only had a chance to work on small parts,
1'-2' long

07-25-2003, 05:49 AM
Thanks Chief! I have been wondering about that for some time. BTW I got a Captain's Mast because I entered the correct diagnosis into an officers medical record once. The Old Man said that I should have known that it was a social disease. Things kind of went south when I told him he should know that Clap, by any other name was clap and I didn't falsify records. He was less than amused. 14 days restriction, but I used it to repaint sickbay and polish up the brightwork. Thrud would have liked it! it was real shiney.

John B

[This message has been edited by jr45acp (edited 07-25-2003).]

[This message has been edited by jr45acp (edited 07-25-2003).]

07-25-2003, 07:32 AM
"Level" is only a means to an end, a lathe that turns parallel. It's often seen as a requirement in itself -- the lathe MUST be level -- but in fact the real requirement is a straight lathe bed. "Level" is just one way of setting up a lathe so it's straight.

07-25-2003, 09:09 AM
SGW, you are exactly right. I pointed out in another of these issues that people say, "Never leave a chuck key in the chuck", when what is meant is, "Never start a spindle with the chuck key in the chuck."
I served in the Navy as a Machinery Repairman aboard an LSD -- an amphibious type -- and we had a 20" Lehman engine lathe with an 8' bed. I put an indicator on the tool post once with the button on the chuck and, as the ship rolled, there was about .003" movement from the twisting action. But I made pump shafts and once even a shaft for a turbine blower and they worked. I suppose you could install a lathe on a roller coaster and, as long as the ways are parallel with the spindle you could use it.

07-25-2003, 10:37 AM
This is a question I find furthest from dumb actually! most lathes never seem to get properly leveled. Few knows how, it seems.

Ask a MS-student if he knows how! bet u he don't! even tho it's so very important!

07-25-2003, 12:08 PM
As SGW points out, it isn't level that matters. It is alignment. Industry uses slant bed lathes where the bed is at a 45 degree or so angle so the chips fall off better and it is easier to load. Leveling is just a convenient reference technique.

07-25-2003, 06:52 PM
Randolph is correct, it's the alignment,
The only time I couldn't make something was when the ship backed down hard (everything vibrated) or I couldn't stand up because of the rolling of the ship. One the bigger ships with an expansion joint you could watch this open and close and inch or two in heavy weather.