# How to avoid running into my chuck on power feed.



## twooldvolvos (Oct 31, 2020)

As a new lathe owner, I am very leery about running my cutter into my chuck, especially if the power feed for the apron is engaged toward the chuck.  So what are the safeguards against doing this?  I have a carriage stop.  Would the clutch slip if the apron hit the stop?


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## markba633csi (Oct 31, 2020)

Running a lathe requires concentration of course;  the clutch may slip, but the scenario you described will cause damage and/or injury and you want to avoid that.  Keep the spindle drive belt on the loose side as a precaution.
Use the slow spindle speeds at first as you get comfortable with the machine. Never leave the chuck key in the chuck after tightening.
-Mark


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## Nogoingback (Oct 31, 2020)

If you have a clutch. it should slip if you hit the stop, though it isn't a good idea to power feed it to the stop in the expectation that it will solve the problem.  You can power feed just short of the stop and manually advance the carriage
the rest of the way to the stop.
The safeguard against crashing your lathe is being attentive to what you're doing.


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## dbb-the-bruce (Oct 31, 2020)

Use a stop, keep your hand on the belt tension lever. Keep the belt engaged tension a little light until you have confidence and need the torque.
Southbend has a clutch in the carriage drive that generally saves it from damage but you shouldn't rely on it as your first choice.


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## markba633csi (Oct 31, 2020)

Imagine being a metal shop instructor in Jr. High or High school back in the day (I had it in both)
All those young guys and a few gals and a room full of finger breaking, flesh ripping machines  
-Mark
ps I think the woodshop was more dangerous


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## DavidR8 (Oct 31, 2020)

On my 10K I did some experiments to get a feel for how many turns of the clutch knob achieved engaged the clutch.
When I’m doing an op that runs close to the chuck I have my hand on the clutch knob and disengage it when/where I want the carriage to stop.

I was recently doing some work and did over a dozen passes to within 1/32” of the chuck without mishap.

As others have said. Running a lathe requires full concentration at all times.


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## tech610 (Oct 31, 2020)

What lathe do you have? Does you lathe have a factory carriage stop that automatically disengages the power feed?


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## Flyinfool (Oct 31, 2020)

The clutch MAY slip and prevent major damage. BUT there will still be significant damage AND/OR bodily injury. With any machine you have to pay very close attention to what you are doing or it will bite, and bite hard.


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## SLK001 (Oct 31, 2020)

twooldvolvos said:


> So what are the safeguards against doing this?



Concentrating on your task at hand and keeping your head out of your you-know-what are key here.


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## twooldvolvos (Oct 31, 2020)

"What lathe do you have? Does you lathe have a factory carriage stop that automatically disengages the power feed?"

I have a south Bend 10K.  In the picture you can see my apron and carriage stop.  I do not think the lathe is designed to disengage the power feed if the apron hits the stop.  Please correct me if I am wrong.


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## ThinWoodsman (Oct 31, 2020)

DavidR8 said:


> On my 10K I did some experiments to get a feel for how many turns of the clutch knob achieved engaged the clutch.



This is pretty much what it takes. I was terrified of using the power feed, but eventually sat down and just put an afternoon into getting a feel for it. Mark a shoulder on some work, nowhere near the chuck of course, and practice using the feed and disengaging in time. Start with the slowest possible feed, and work your way up. It doesn't take long to get a feel for it.

Once you're no longer worried about running into the chuck (say, a week's worth of projects involving the power feed), then start looking for ways to make disengaging the feed more repeatable. One of the simplest is to use a dial indicator clamped to the ways: when the needle hits the 0 (or whatever mark you are using), disengage. A DRO can be used for the same purpose, though it is a much greater project to install. The simplest method is to use a sliver of light between the tool and the work, the carriage and the stop, whatever - this is of course going to be lathe- and setup-specific, but basically you have your eye near the tool (not on a dial indicator or DRO), watching an ever-diminishing crack of light, and when the light vanishes, disengage the feed. As always, practice with a dry run (no power, tool not actually cutting) to verify when to disengage. With a shoulder, I tend to err towards early disengagement on initial passes, with the final pass establishing the shoulder completely - a slightly heavier cut but only for .010 or so.

Side note: pretty surprised nobody has punted with "dog clutch!" yet


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## SLK001 (Oct 31, 2020)

twooldvolvos said:


> I have a south Bend 10K.  In the picture you can see my apron and carriage stop.



You NEVER, repeat NEVER want to hit a carriage stop under power feed.  The things that this can damage/break are numerous.


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## Ken from ontario (Oct 31, 2020)

Nogoingback said:


> You can* power feed just short of the stop and manually advance the carriage
> the rest of the way to the stop.*
> The safeguard against crashing your lathe is being attentive to what you're doing.


Great advice.^^^.


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## tech610 (Oct 31, 2020)

twooldvolvos said:


> "What lathe do you have? Does you lathe have a factory carriage stop that automatically disengages the power feed?"
> 
> I have a south Bend 10K.  In the picture you can see my apron and carriage stop.  I do not think the lathe is designed to disengage the power feed if the apron hits the stop.  Please correct me if I am wrong.


I'm not familiar with 10K, but it looks like a carriage stop for manual turning. There are lathes that have a special mechanism designed to disconnect the power feed when the carriage reaches a certain point. If your lathe doesn't have this feature I wouldn't use a power feed and rely on a manual stop.
A simple DIY manual spindle crank would be a way to go.


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## Mitch Alsup (Oct 31, 2020)

Nogoingback said:


> You can power feed just short of the stop and manually advance the carriage the rest of the way to the stop.



Use a dial indicator and use the automatic feed until you are within 0.050 of the stop, then switch off the autofeed, and feed until the dial indicator reads 0.000.



> The safeguard against crashing your lathe is being attentive to what you're doing.



The same standard applies to mils, shapers, grinders, and especially saws.


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## Asm109 (Oct 31, 2020)

I set up a dial indicator to show me where I want my cut to stop. Usually set it up so it the dial makes a full turn and then I stop on 0.  Watch the dial come around and disengage the feed some amount before zero, then turn it in by hand.  As you practice you can get it to stop inside .010 with ease.


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## Asm109 (Oct 31, 2020)

Mitch Alsup said:


> Use a dial indicator and use the automatic feed until you are within 0.050 of the stop, then switch off the autofeed, and feed until the dial indicator reads 0.000.
> 
> 
> 
> The same standard applies to mils, shapers, grinders, and especially saws.


Great minds think alike.  You beat me to it!


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## silence dogood (Oct 31, 2020)

In our freshman year of high school, the machine shop teacher had the kids whom first started on the lathe cut from headstock to tailstock.  It means that you must use a opposite shaped bit and run the feed screw in reverse.  It does not mean that you can take a coffee break.  However, it sure is a lot less sweat, especially in this case, on the shop teacher. Think about it, the lathe does not care.  The end result is still the  same. Even Joe Pie  sort of does the same thing except it was with threading.


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## mmcmdl (Oct 31, 2020)

twooldvolvos said:


> As a new lathe owner, I am very leery about running my cutter into my chuck, especially if the power feed for the apron is engaged toward the chuck. So what are the safeguards against doing this? I have a carriage stop. Would the clutch slip if the apron hit the stop?



There are no fail safe solutions to your question . You never feed into the stop even if the machine has a clutch , bad things can and will happen . A manual machine will always need an attentive operator . Feed up close to your stop and trip the power feed , then hand dial it to the stop . An indicator , travel dial or DRO is a helpful accessory but not needed and you'll get more comfortable doing this with more machine time .


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## Jim F (Oct 31, 2020)

silence dogood said:


> In our freshman year of high school, the machine shop teacher had the kids whom first started on the lathe cut from headstock to tailstock.  It means that you must use a opposite shaped bit and run the feed screw in reverse.  It does not mean that you can take a coffee break.  However, it sure is a lot less sweat, especially in this case, on the shop teacher. Think about it, the lathe does not care.  The end result is still the  same. *Even Joe Pie  sort of does the same thing except it was with threading.*


He does that running the lathe in reverse.
We cannot run our SB lathes in reverse, lest the chuck comes off.
He would have to use the reversing lever to machine away from the chuck, like cutting LH threads.


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## dbb-the-bruce (Oct 31, 2020)

dbb-the-bruce said:


> Southbend has a clutch in the carriage drive that generally saves it from damage but you shouldn't rely on it as your first choice.



Perhaps my dry and sarcastic sense of humor didn't really translate to a quick Saturday morning response, My Bad.

David R8's response reminded me that I often to the same



DavidR8 said:


> On my 10K I did some experiments to get a feel for how many turns of the clutch knob achieved engaged the clutch.
> When I’m doing an op that runs close to the chuck I have my hand on the clutch knob and disengage it when/where I want the carriage to stop.



The original posters question is specifically in regards to his SouthBend 10K - which has (to my knowledge) the exact same controls as my 9A

The clutch on for the power feed on these lathes is engaged / disengaged with the twist of a knob on the carriage, that's it, that's all you got other than disengaging the drive belt. Additionally, how tight the clutch holds is controlled by how hard you twist the knob.

If you don't crank the hell out of the clutch knob, it will be the first point in the drive train to slip IF you happen to screw up and hit the stop or something else (going toward the tail stock, you can bind up the carriage on the tail stock). There is no way to "trip the power feed" on these lathes. (correct me if I'm wrong).

To be clear, you should never CHOOSE to use a stop as the way to stop carriage motion. I will often set one up to prevent me from doing something stupid, like manually cranking the carriage into the chuck by hand when working close to the headstock. When learning to use my lathe there were probably a couple of occasions where I screwed up and ran the carriage into the stop - the clutch slipped (I didn't over crank it) and / or the belt slipped off the headstock. My lathe is running as good as it did when I purchased it. 

These SouthBend lathes are old-school and very well thought out and refined designs for manual turning with HSS bits. The engineers built them to survive common mistakes. (I'm not an authority, that's my opinion).

@twooldvolvos - You've got a great lathe and you are approaching using it with the right attitude.
Enjoy


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## silence dogood (Oct 31, 2020)

To Jim F:  you are correct on Joe Pie.  Bad example.  At school, we did not run the lathe in reverse, just the lead screw.  Should have made this clearer.


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## Jim F (Oct 31, 2020)

silence dogood said:


> To Jim F:  you are correct on Joe Pie.  Bad example.  At school, we did not run the lathe in reverse, just the lead screw.  Should have made this clearer.


I was wondering why SB even put a reverse switch on their small lathes, then I remembered about my collet adaptor.


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## mickri (Oct 31, 2020)

First off a carriage stop really doesn't stop the carriage at least on my lathe.  The carriage will push it no matter how tight I clamp it to the ways.

This is what I do.   I set the carriage stop.  As the carriage approaches the stop I move a piece of paper back and forth with my left hand between the carriage and the carriage stop.  My right hand is on the half nut release lever.  When the piece of paper catches I release the half nuts.  It really doesn't seem to be a big deal.  It does require paying attention to what you are doing.  But then everything you do on a manual lathe requires paying attention to what you are doing.


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## dbb-the-bruce (Oct 31, 2020)

You are talking about something completely different - using the lead screw / half nuts, typically only used for threading. And yes, the stop is not going to help at all if you have engaged the half nuts on the lead screw.

We may very well be talking about different revisions of the same lathe - My lathe has a keyway in the lead screw that drives the carriage (X or Y) that is independent of using the lead screw to drive the carriage when cutting threads. Perhaps older lathes don't have this.

And yes - using the lever on the carriage to engage the half nuts on the lead screw, cutting threads to a shoulder is another level of anxiety!


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## Jim F (Oct 31, 2020)

dbb-the-bruce said:


> You are talking about something completely different - using the lead screw / half nuts, typically only used for threading. And yes, the stop is not going to help at all if you have engaged the half nuts on the lead screw.
> 
> We may very well be talking about different revisions of the same lathe - My lathe has a keyway in the lead screw that drives the carriage (X or Y) that is independent of using the lead screw to drive the carriage when cutting threads. Perhaps older lathes don't have this.
> 
> And yes - using the lever on the carriage to engage the half nuts on the lead screw, cutting threads to a shoulder is another level of anxiety!


Some SB lathes only have the half nuts for z axis feed, like my 9C.
I think small Atlas are the same.


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## SLK001 (Oct 31, 2020)

dbb-the-bruce said:


> Southbend has a clutch in the carriage drive that generally saves it from damage...



Once engaged, the clutch doesn't slip upon hitting a carriage stop.  It can hold with enough pressure to break things like gear teeth.


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## dbb-the-bruce (Oct 31, 2020)

Jim F said:


> Some SB lathes only have the half nuts for z axis feed, like my 9C.
> I think small Atlas are the same.


Interesting, I always assumed that the 9C were for large production situations. IE. you a have a room full of lathes that are setup to make specific parts. I can see how in a situation like that you could expect the operators to use just the half nut lever to control the carriage. Also, you would need to change gears out to change the feed? 

Glad I have a toolroom lathe.


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## Jim F (Oct 31, 2020)

dbb-the-bruce said:


> Interesting, I always assumed that the 9C were for large production situations. IE. you a have a room full of lathes that are setup to make specific parts. I can see how in a situation like that you could expect the operators to use just the half nut lever to control the carriage. Also, you would need to change gears out to change the feed?
> 
> Glad I have a toolroom lathe.


C models were for mechanic and home shops, not for production.
Yes, the change gears control the power feed rate,also.
my 9C.


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## SLK001 (Oct 31, 2020)

dbb-the-bruce said:


> Interesting, I always assumed that the 9C were for large production situations.
> 
> Glad I have a toolroom lathe.



Most 9C were sold to individuals.  Having had a 9C from 1934, then upgrading to a 10L toolroom lathe, I too am glad I now have a toolroom lathe!


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## tq60 (Oct 31, 2020)

Our L&S has carriage offers stop that is an additional control rod.

It kicks out the drive when hit.

South Bend has no provisions for same so you need to pay attention to the machine and remember to release clutch a bit ahead of time and feed manually.

The carriage stop is made for stopping carriage with hand feed.

Sent from my SAMSUNG-SM-G930A using Tapatalk


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## dbb-the-bruce (Oct 31, 2020)

Jim F said:


> Some SB lathes only have the half nuts for z axis feed, like my 9C.
> I think small Atlas are the same.


Thank you for correcting my axis naming! (is that just a CNC thing? how long has it been around?) - BTW, has anyone ever used the y axis on their lathe?


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## dbb-the-bruce (Oct 31, 2020)

Jim F said:


> C models were for mechanic and home shops, not for production.
> Yes, the change gears control the power feed rate,also.


Ugh


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## Jim F (Oct 31, 2020)

dbb-the-bruce said:


> Thank you for correcting my axis naming! (is that just a CNC thing? how long has it been around?) - BTW, has anyone ever used the y axis on their lathe?


Not yet, I do have a Palmgren 250 that came with it.


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## Jim F (Oct 31, 2020)

dbb-the-bruce said:


> Ugh


No power cross feed, either.


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## Jim F (Oct 31, 2020)

SLK001 said:


> Most 9C were sold to individuals.  Having had a 9C from 1934, then upgrading to a 10L toolroom lathe, I too am glad I now have a toolroom lathe!


My C is a 1947 vintage.


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## Winegrower (Oct 31, 2020)

tq60 said:


> Our L&S has carriage offers stop that is an additional control rod.
> 
> It kicks out the drive when hit.



The Takisawa lathe has an additional control bar parallel to the lead and drive screws with 4 adjustable stops, that can be instantly rotated into position and removed the same way.   They put up an arm that trips the feed mechanism and stops the carriage.   It repeats to about 0.01” maybe, works for longitudinal feed but not for half nut threading.   Which is too bad, that would really be a good feature.

Frankly letting the lathe run unattended and relying on this feature would not be the target use for me, but i have set it up as a kind of fail safe backup, in case some thing that shines goes by.


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## dbb-the-bruce (Oct 31, 2020)

Jim F said:


> Not yet, I do have a Palmgren 250 that came with it.


Cool! Mine came with the original SouthBend milling attachment, it's cute. I did a project or two with it and then bought a mill (ha!)


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## Jim F (Oct 31, 2020)

dbb-the-bruce said:


> Cool! Mine came with the original SouthBend milling attachment, it's cute. I did a project or two with it and then bought a mill (ha!)


I actually bought my mill/drill before I got my lathe.
Project priorities.........
Now I am looking at a 3D printer...........


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## mickri (Nov 1, 2020)

dbb-the-bruce my lathe is a craftsman 12x36.  These lathes do not have a clutch like the 10K to engage the lead screw for turning.  The QCGB in addition to threading also has settings for moving the carriage for turning.  I use the carriage stop as a guide whenever I need to stop the carriage at a precise location whether I am cutting threads or just turning.  It is particularly handy when threading or boring a blind hole.


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## addertooth (Nov 1, 2020)

No clutch on my lathe.  The solution is "lots of coffee, Cat-Like reflexes, and paying attention like you are driving in heavy traffic in a chaotic Asian country".


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## cathead (Nov 1, 2020)

Just because you have a power feed does not mean you have to use it.  Run it manually until you feel comfortable using
it.


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## silverchips (Nov 1, 2020)

I'll jump in but a little late and maybe not the best solution for you but a couple fo years ago I went to go look at a home shop of an aerospace engineer who passed away and the son wanted to unload his machine.
He had a industrial Craftsman lathe with what I thought was a really cool set up to stop the tool from crashing into the chuck. He installed a rail with anvil looking stop to trip the feed screw that you could adjust. He modified the feed screw nut lever to make it longer and to disengage when it passed over the anvil stop. I tested it and it worked great.
These are the only pics I have of the day I saw it and unfortunately the deal didn't work out. The previous owner of this lathe had all kinds of cool machines and tooling that I was able to come home with but not the lathe. He originally designed the food carts for airlines that get pushed down the aisle to feed you your booze and glorified Hungry Man meals. I have one in my shop that was made as a prototype for PamAm and love it.

Not the best pics but should be understandable and could be one solution for you?


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## DavidR8 (Nov 1, 2020)

Interesting 
What was the purpose of the plate on the headstock?


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## addertooth (Nov 1, 2020)

It looks like it is part of the "three-sided-box" which entirely wraps the area where chips could be flung (besides Towards the operator).  It is best seen in picture number 3.


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## DavidR8 (Nov 1, 2020)

addertooth said:


> It looks like it is part of the "three-sided-box" which entirely wraps the area where chips could be flung (besides Towards the operator). It is best seen in picture number 3.



Doh!
Guess I should have looked a little less hard 


Sent from my iPhone using Tapatalk


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## SLK001 (Nov 1, 2020)

It looks like that three-sided box is made out of 3/4" aluminum plate!


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## Flyinfool (Nov 1, 2020)

Sometimes you just make things from what you have on hand.


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## dpb (Nov 1, 2020)

Set your carriage stop at the end of your cut.  With the carriage at this position, spin the chuck by hand, to check for interference.  If you have a graduated carriage wheel, set it to zero, at this position.  If you don’t have a graduated wheel, mark its position with a grease pencil, or something.
Make your cuts using power feed.  As you approach the end point, watch your carriage wheel.  Disengage before reaching your reference point on the wheel, and make the final movement to the stop by hand, should only be a few thousandths, with practice.
Shorter answer:  disengage power feed before crashing.


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## silverchips (Nov 1, 2020)

dpb is correct and he said it better than in my brief description. you can move the power feed trip (I call it an anvil) anywhere you want to and set it where you want the carriage to stop, would be useful for repeating when threading.....etc, it didn't interfere with the cross slide power feed lever. When testing it, the carriage stopped immediately as it passed over the anvil. I would make the anvil trip a little more convenient to move, it was bolted down tight for basic stop just before tool would hit the chuck but it was adjustable any anywhere on the entire bed way.
I like this solution and could see this being an option for the OP? What do you guys think?

What you see and asked about is a very well made chip screen made out of aluminum sheeting (pressed, shaped and welded and not 3/4") and a clear polycarbonate screen that was hinged (as seen in pic #3). It was was not bad at all, well designed, zero vibration, didn't seem to get in the way of anything and easy to deal with. I myself would probably leave it up, out of the way to watch the cutting closer up as I love picking out swarf sticking to my arms 

It was a good little lathe with very little use on it, hopefully it found a good new owner.


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## Lo-Fi (Nov 1, 2020)

Just to chime in and give an alternative...

My power hacksaw has a plunger at the bottom of it's travel which activates a micro switch. The switch is wired into the fifth port of the No Volt Release switch thats used for the emergency stop button. You could easy rig up a carriage stop with similar. It won't stop immediately, of course, but will work perfectly well if placed with a bit of clearance before the worst happens.


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## addertooth (Nov 1, 2020)

Most importantly, the position of the saddle will not be the same for every crash.  If your compound feed is at an angle towards the chuck, and fed forward, a collision will occur earlier.   Any compensation mechanism you make will need to be adjustable to allow for this.


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## silverchips (Nov 1, 2020)

Thats correct addertooth, you need an easy and convenient way to adjust the stop for different scenarios.


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## epanzella (Nov 3, 2020)

IF ( and that's a BIG if) your lathe has a clutch a stop could avoid a crash but it's a bad practice. If your lathe has no clutch a stop will break parts.  What will you do when threading? The lead screw has no clutch.  Much better if you just learn to pay attention and develop good habits at the lathe.


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## Nogoingback (Nov 3, 2020)

The OP went AWOL a long time ago.


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## twooldvolvos (Nov 4, 2020)

Nogoingback said:


> The OP went AWOL a long time ago.


I'm still here and learning a lot from all the responses.


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