lathe question

on say a chinese lathe about 12x36 what are the 3 rods that go to the crossslide, i know one is the lead screw what are the other two, they dont appear to have any threads...thanks tony

Reply to
Tony
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Could you possibly mean the front apron? One will be slotted and use for power to the crosslide. The other may be connected to a lever control on the apron for feed control. Respectfully, Ron Moore

Reply to
Ron Moore

thanks ron, thats what i thought...tony

Reply to
Tony

I've seen this:

  1. Leadscrew, for thread-cutting
  2. Drive shaft, for self-acting movement of saddle or cross-slide
  3. Switch "remote control" shaft, so you can switch the motor from the saddle position.

  1. & 2. are combined on some lathes.

Reply to
Jordan

According to Tony :

One is the drive rod to the power feed. It has a keyway the whole length to drive the internal gearing in the apron. This makes it easier to control the feed separately from the threading pitch.

The other is the forward/stop/reverse control. The switches are inside the left-hand pedestal, and there is a lever on the carriage which rotates the rod through a similar keyway, so you can control the spindle from anywhere along the bed, right at the carriage wherever it is at the moment.

Enjoy, DoN.

Reply to
DoN. Nichols

One typically is the control rod..the forward/reverse lever that is usually mounted on the carriage operates this rod, which throws a microswitch for forward and one for reverse

The other is the power feed rod. It supplies rotory motion to the carraige that in turn operates both cross feed and longitudnal feed.

Gunner

The aim of untold millions is to be free to do exactly as they choose and for someone else to pay when things go wrong.

In the past few decades, a peculiar and distinctive psychology has emerged in England. Gone are the civility, sturdy independence, and admirable stoicism that carried the English through the war years . It has been replaced by a constant whine of excuses, complaints, and special pleading. The collapse of the British character has been as swift and complete as the collapse of British power.

Theodore Dalrymple,

Reply to
Gunner

thanks to all for the replies, another question, the lathe in the link picture, the silver lever would be either the 1/2 nuts or the long feed? the red knob would be the reversing lever? and the black lever dont know? thanks for taking time to educate me..tony

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Reply to
Tony

Typical Chinese lathe. Badged as Birmingham and a host of others

Red knob is start spindle forwards/reverse

Silver lever is half nut

Black lever to right of handwheel, ..pull right and down..usually long feed. Push left and up..cross feed. Sometimes reversed.

Gunner

"I think this is because of your belief in biological Marxism. As a genetic communist you feel that noticing behavioural patterns relating to race would cause a conflict with your belief in biological Marxism." Big Pete, famous Usenet Racist

Reply to
Gunner

thanks gunner, so most of the chinese like this one has power cross feed. what was confusing me was the dual function of the black lever..thanks again..tony

Reply to
Tony

Any lathe bigger than a toy will have powered crossfeeds. The purpose of the odd single control, is to make sure you dont put it in both crossfeed AND longitudnal feed at the same time. Some older lathes will allow this by design or intent..others have no lockout and then gears go BINGK!

Btw..I serviced one of those exact lathes not long ago..badged "Webb".

Not a bad bit of kit, electrical was a bit under designed..but it worked well enough. Had an "operator issue"...lol

Gunner

"I think this is because of your belief in biological Marxism. As a genetic communist you feel that noticing behavioural patterns relating to race would cause a conflict with your belief in biological Marxism." Big Pete, famous Usenet Racist

Reply to
Gunner

According to Tony :

[ ... ]

[ ... ]

O.K. Looking at that -- and trying to work from memory with a similar gearhead lathe (JET brand) from perhaps fifteen years ago or so, I would say:

Silver lever half-nuts

Black lever cross/longitudinal feed. (On my Clausing, it has to move in a Z pattern, so you can't switch from cross to longitudinal by accident. Up may be cross and down may be longitudinal feed.

Red-handled lever Spindle forward/stop/reverse

There is too much detail loss to the JPEG compression for me to tell whether it has both inch and metric threading, but given the number of charts on the housing, I think that it does.

And -- at another guess, I would think that of the four knobs at the bottom of the front panel, the upper two are for threading, and the lower two for feeds.

The black-handled lever pointing down in the upper panel *may* be to select between metric and inch threads. (Or perhaps it selects back gear, if there *is* a separate back gear on a gearhead lathe like this.)

But I'm having difficult identifying which knob selects between RH and LH threading.

O.K. Finding a web site with some other closer photos, I think that the black-handled lever pointing down is what does that.

Overall -- it looks like a nice machine, and one which I might like to have. It needs a lever-closed collet setup (the spindle bore is large enough for 5C collets), and I would like a bed turret (not likely to show up) to fit it.

But overall, it does look like a capable machine.

Advice which I have had from a really good machinist who had one similar at work (again -- fifteen years ago) was to *never* take out the plug in the gap-bed -- as it is almost impossible to get it back truly accurately.

Enjoy, DoN.

Reply to
DoN. Nichols

Some of the older lathes that I ran back in the late 50s allowed simultaneous engagement of the longitudinal and cross feeds. This would cut a 60 degree included angle point because the feed per rev was geared differently for the cross and longitudinal feeds.

What you could not do was engage the half nut and longitudinal feed at the same time. One of the cast iron wonders we had that was converted from ovehead line shaft power [may even have had babbit bearings] would allow this. Did have a QC gear box though.

I can't recall the names of the lathes, but one had a knob you tightened up to engage the feed clutch which would sometimes not release when you unscrewed the knob, and you had to have a lead hammer handy to give the shaft a good whack to jar it loose. Knob also turned, so depending which way you were cutting you had to turn it "quickly" to get it to release. Feeding the other direction you just had to grab it and let it unscrew its self, unless the clutch "hung." Made cutting to shoulder a real joy, and I scrapped a lot of parts....

Unka George (George McDuffee)

...and at the end of the fight is a tombstone white with the name of the late deceased, and the epitaph drear: ?A Fool lies here, who tried to hustle the East.?

Rudyard Kipling The Naulahka, ch. 5, heading (1892).

Reply to
F. George McDuffee

The real issue is there must be a lockout to prevent simultaneous engagement of the half nuts and the longitudinal feeds. Many older lathes allow this.

If this happens, it effectively locks the gear train (two different gear ratios in parallel) and will blow up the gear train that feeds the leadscrew.

Jim

Reply to
jim rozen

Sounds a lot like a Hendey, except with mine, there's a feed direction lever on the carriage and its operating rod also has a pair of stops. Carriage hits the stop and disengages the feed automagically... --Glenn Lyford

Reply to
glyford

thanks for all the advice...tony

Reply to
Tony

Odd..I hear an echo....

Gunner

"If I'm going to reach out to the the Democrats then I need a third hand.There's no way I'm letting go of my wallet or my gun while they're around."

"Democrat. In the dictionary it's right after demobilize and right before demode` (out of fashion).

-Buddy Jordan 2001

Reply to
Gunner

Nope, you cautioned about the cross and longitudinal feeds at the same time:

================ Any lathe bigger than a toy will have powered crossfeeds. The purpose of the odd single control, is to make sure you dont put it in both crossfeed AND longitudnal feed at the same time. Some older lathes will allow this by design or intent..others have no lockout and then gears go BINGK! =================

My specific caution was about the half nuts and the longitudinal feeds at the same time. That *will* bust the geartrain. My seneca falls allows that, and the bracket for the leadscrew bears the repair that shows some fool did it once, a long time ago.

Most machines don'r mind it much if you engage the cross and carriage feeds at the same time. You just get an angled cut....

Jim

Reply to
jim rozen

================== May well have been. Hard to remember but as I recall there were a number of flanges, bosses, threaded holes, etc. that appeared to have no function on the apron. Automatic stop may have been removed. Sorta' rember a name of Gisholt or Gisholdt, but that could have been the turret lathe /chucker. Big heavy machine -- no demand for a gym or spa for a workout in those days.... No A/C in the shop either.

Unka George (George McDuffee)

...and at the end of the fight is a tombstone white with the name of the late deceased, and the epitaph drear: ?A Fool lies here, who tried to hustle the East.?

Rudyard Kipling The Naulahka, ch. 5, heading (1892).

Reply to
F. George McDuffee

1 is the leadscrew, 2 is the feed shaft, 3 will be connected to the fwd/rev lever, and operates switches at the headstock end.
Reply to
Wayne Weedon

Once -- or perhaps more than once -- an perhaps more than one fool. :-)

I've encountered some which would allow that, such as a Sobel. And they gave a nice 60 degree point. :-)

However, others, such as my 12x24" Clausing, where the design prevents that. The single lever which selects crossfeed or longitudinal (*not* threading feed, however) moves in a slot wrapped around a cylinder pointing to the tailstock end of the lathe. You pivot the lever up for crossfeed, or down for longitudinal (or is it backwards? My *hands* know when I'm at the lathe, at least :-), but you have to slide it towards the tailstock to reach the slot for one, and towards the headstock to reach the slot for the other. The total slot looks somewhat like this (but wrapped around the cylinder) (View with a fixed pitch font (like Courier), or the vertical parts won't line up properly with the horizontal.

| __| | |

Enjoy, DoN.

Reply to
DoN. Nichols

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