Lathe carriage stops?

I would like to know if I can buy some gizmo that can provide a
definite, positive stop to the lathe carriage before the cutter or the
carriage hits the chuck. Any suggestions, at least what are these
things called.
i
Reply to
Ignoramus18741
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You got the name right. They also make micrometer carriage stops so that you can move the carriage a controlled amount.
I often use a carriage stop when turning to a shoulder. After the bulk of the turning is done, I can adjust the micrometer dial a little to take a cleanup cut on the shoulder or get the final dimension correct.
My atlas lathe came with a homemade carraige stop. Since the atlas was a flat bed, it was very easy to make something that clamped to the bed with a fine thread screw sticking out the side that stopped the carriage.
My rockwell lathe has a V way so the carriage stop has to have a matching V. Same principle, but this one also has a micrometer head for precise adjustment.
chuck
Reply to
Chuck Sherwood
There is a good article in the latest "Home Shop Machinist", available now in good bookstores, on a device to automatically disengage the half nuts at the end of threading. It's very clever, but I don't know if it will work on a South Bend. The exact reference is:
"An Automatic Carriage Stop for Thread Cutting" by James McKee M/J 05 HSM
If you want something that will prevent power-crashing the carriage into the chuck when powerfeeding, then you need a limit switch setup, perhaps backed up with a solid beefy carriage stop. I don't know where plans for a limit switch setup are.
GWE
Reply to
Grant Erwin
Here ya go
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- Rex Burkheimer WM Automotive Fort Worth TX
Ignoramus18741 wrote:
Reply to
Rex B
My 1938 F.E. Reed has such a feature. One uses a split collar around the feed drive rod as the stop. When the carriage finally bumps the collar, it moves the feed rod left, disengaging a spline clutch. [and it doesn't work using the threading lead screw ! :( ]
LLoyd
Reply to
Lloyd E. Sponenburgh
Nice. You could make it with a bolt instead of the micrometer for simple jobs.
I like the parent lathe project page.
Reply to
Chuck Sherwood
Be *very* cautious in your application of carriage stops, especially if you machine doesn't have a reactionary clutch for the longitudinal feed. One mistake can cost you the feed train. It's especially bad if you're using a lead screw with half nuts, such as when threading. The slightest mistake in judgment will destroy your machine.
Harold
Reply to
Harold and Susan Vordos
very true, but hitting anything can be bad news. For example I frequently use a carriage stop when turning to a shoulder. I believe that running the toolbit into the shoulder isn't much different than running the carriage into the carriage stop. Both will put a big load on the feed train. You got to know when to dis-engage!
cs
Reply to
Chuck Sherwood
Thanks to all... I see the issue a little bit more clearly.
i
Reply to
Ignoramus18741
=========== Very true -- better to ruin what you are machining than the machine. Suggest that you consider using a magnetic backed dial indicator. You can get the micrometer feed control and if you over-run the stop ythere is less damage of machine damage.
Reply to
F. George McDuffee
Exactly. I heard once that bad golfers plan for failure while good golfers plan for success.
Shit happens, but if you haven't the presence of mind to keep track of your stop, perhaps you deserve to buy a new gear...
I worked on a Harrison lathe a couple of years ago that had a friction clutch on the feed rod. A bit fiddly to get the torque rating correct, but it worked. Further, many lathes are made to have carriage stops turn the power feed off automatically. Ignoramus should check his machine for this capability. The machines I've seen which this feature typically have a pin sticking out where a carriage stop would normally make contact.
Regards,
Robin
Reply to
Robin S.
I bought a brass micrometer for $2.49 at HF for just this purpose. I'll cut the frame off and keep the good part. Not much more (and not much more accurate) than a good bolt. - - Rex Burkheimer WM Automotive Fort Worth TX
Chuck Sherwood wrote:
Reply to
Rex B
If I understand you correctly, that's pretty much what I do. when turning, I run the feed until the carriage is ALMOST to the carriage stop, then disengage the feed, and finish to the stop by hand feeding the carriage.
When threading, I first cut a stop groove at the end of thread location (when that is permissible), then cut the thread, I run the carriage under power until the threading tool is in the stop groove, then disengage the feed. I don't see much use for the carriage stop here, except to keep you from accidentally HAND running the carriage past the stop groove,or running into the chuck.
Sure, if you run into the stop under power feed you'll likely make a mess of things. But you'll make just as big, or maybe worse, a mess by over running your cut into a shoulder, or running the carriage into the chuck.
A carriage stop the automatically disengages the feed is a whole different animal than a passive stop. Most small lathes don't have that feature.
Like most everything, carriage stops have their place, and they can be mis-used.
Dan Mitchell ============
Reply to
Daniel A. Mitchell
You know, the factory carriage stops I most often see listed on ebone are for the 10" & 12" Atlas lathes. That is the exact machine you would NOT want to use a carriage stop on. All the gears and the halfnuts are Zamac potmetal. Perhaps Atlas/clausing, in their wisdom, figured out that the more of those found their way onto lathes, the more replacement parts they could sell :)
- - Rex Burkheimer
Harold and Susan Vordos wrote:
Reply to
Rex B
True enough, but if the tool jams in the work you may well damage any of several parts of the lathe anyway. That's hardly less damaging than running into a carriage stop under power.
Some lathes have crossfeed stops for similar reasons.
One place I use a carriage stop is when I HAVE to work very close to the chuck. Often such work is hand fed. I do a set up, position the carriage stop, and turn the spindle over by hand looking for any interferrence, resetting the carriage stop as needed. Then in a moment of inattention of stupidity I can't (easily anyway) run the tool or carriage into the chuck.
When working in close quarters, I almost always try a mock rotation or two by hand before engaing a power feed. One learns this especially when running a shaper! It's easy to overlook some potential collision of moving parts.
Dan Mitchell ============
Reply to
Daniel A. Mitchell
It's cheaper and simpler to replace just a stripped pot metal change gear then have to replace a bent spindle or broken casting! ... Especially since you'll likely break the change gear doing THAT anyway! The soft metal gears act a lot like a shear pin. They're there for when you do something DUMB!
Otherwise, the pot metal change gears seem to last just fine. I've been using an Atlas 6" with them for nearly 30 years. They show little wear.
Dan Mitchell ============
Reply to
Daniel A. Mitchell
I have a stop on my lathe however I only run up close to it and then hand feed, as there is no clutch or auto disengage on it. I normally use a mike head in it or can substitute a threaded rod and threaded bushing if its just for a plain stop, without the need for adjustment.
The one I made is on my Projects Page on my website.
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============================================== Put some color in your cheeks...garden naked!
Reply to
~Roy~
Granted, but why not give us steel gears and a cheap shearpin on the leadscrew? Instead, we have Zamak reversing box gears (3) Zamak change gears (3) Zamak reverse tumber gear (2) Zamak apron bevel gear Zamak leadscrew support
Any combination of these can fail if you crash the tooholder while under powerfeed.
Note: There is a very popular mod of the right leadscrew support, replacing the Zamak unit with a steel replacement and an aluminum or brass sheerpin.
Don't get me wrong, I like Atlas machines, just finished restoring a 10F. But it is an inexpensive design, intended for home shop use.
Can I interest you in an OE Atlas Carriage stop?
Rex
Reply to
Rex B
I have (and use) a micrometer carriage stop. It has nothing whatever to do with stopping the machine's turning movement in the X axis. Rather, I use it for setting up shoulders. Face a part, mount a cutoff tool, bring the edge of the cutoff tool to rest against the work, zero the carriage stop and bring it to rest against the carriage, then crank out the carriage stop the desired amount and move the carriage (by hand) until it again rests against the stop, then lock the carriage and use the cutoff tool to machine the shoulder.
I don't think a carriage stop of this nature should EVER be used to try to stop the carriage in any kind of safety sense.
There are such carriage stops, but not on my lathe. Typically they kick the carriage feed out of gear. I have heard of lathes without this feature being outfitted with electrical limit switches which will kill the power to the machine. This has somewhat the same effect, except it seems likely that the power train's rotational momentum would keep the carriage feeding for some time before frictional forces (and cutting forces should the cutter be engaged) stopped it.
The 2 kinds of carriage stops I write about are VERY DIFFERENT and they should REALLY not be confused.
I hope that's clear enough.
GWE
Reply to
Grant Erwin
Some of the the Clausing 5900-series lathes have a clutch/brake lever and a kick-out was an option. The kickout will disengge the clutch and engage the brake to stop the spindle fairly quickly. The kickout doesn't seem to be a precision device, though. It doesn't seem like it could be accurately set to better than 50 thou or so.
Reply to
Mike Henry

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