London M. T. configured for threading

What follows is a photo of my London Machine tool lathe instrumented and configured for threading.

What interests me in the position of the compound. All the manuals I've seen on cutting threads with a lathe show the compound 180 degrees from the position shown here, however with the geometry of this lathe that is just impossible. The cross slide won't go over far enough to allow small diameter threading if the compound is rotated with the handle to the back.

Besides that you couldn't reach the handle anyway.
the lathe will swing modestly over 4 feet in the gap, and it appears that if you were doing large diameter thread cutting (say over a couple feet) you could rotate the compound into the classic backwards position (for internal threads)

Any thoughts as to whether this is 'normal' for old lathes or unique to this model

The black tape on the boring bar servies as a high tech depth gauge. There are some surviving degree markers on the compound swing,on the front side, but a couple of punch marks on the back side mark the spot for setting the compound.

On a considerably different scale, my dad's 1948 South Bend 9" doesn't have degree markings for rotating the compound to the rear and I ran into clearance problems IIRC when I tried to set up it. Caught me by suprise since my old ATW and 10L both have them.

Regards,

Greg

rvanatta,
all I get is a square with a red x, not your photo. Should I do something different?
Thermo1

Scratch that last post, the picture just came up. That is some lathe.

Thermo1

Well, one of the reasons I bought the big ATW is that it seemed to be in better condition than this LMT model. This machine spent most of its life in a wood products plant, and was not always loved.


as you Can see from this photo even 4 feet isn't enough swing for some so they hacked out the gap to be even larger. In a 100 years or so, the gap filler is lost and forgotten somewhere, and it has a few peg teeth in the back gears and it has crashed a time or two as well though not on my watch.

My ATW is a heavier duty lathe. the Swings are comparable, but the gear teeth on the back gears are much larger on the ATW---though it lacks the 2 speed back gears of the LMT lathe. Multi speed back gears only seem to appear in large swing lathes, and in the case of the LMT I presume they were included to support the 4 foot gap, though the 30 inches over the bed is not trivial. I suspect the ATW was designed as a 28" and then got 4 inch blocking to 36".

The blocked lathes never seem to be quite what the native designed ones are for some reason.
Always 10 lbs in a 5 lb bag, but the ATW is inherently stonger, with bigger gears and a larger diameter spindle, and I think a heavier cross section bed.

I have found some interesting things though. I can use the 'change gears' that came with the ATW on the LMT lathe---interesting in that I don't have a full set for the LMT. The tooth size is different, but they share a 1-3/4" arbor size so you can switch the whole set---something we have done before. The LMT doesn't run on its original change gears as they were vandalized before we got the lathe and we only bought enough for common threads --- 4,5,6,8 & 12.