# Don't run the boring bar into the chuck jaws on the end of the hole



## Hukshawn (Feb 11, 2017)

Don't run the boring bar into the chuck jaws on the end of the hole cause you're watching the dro and not the work...


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## mikey (Feb 11, 2017)

The boring bar equivalent of the arc of shame, where you run the compound into a spinning chuck - you are not the first, won't be the last. 

Thanks for starting my day off with a smile, Shawn!


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## higgite (Feb 11, 2017)

I, for one, would never be so careless as to commit either of the rookie mishaps that you two guys described. I'm much more diligent than that. But, let’s NOT talk about running the boring bar past the inboard end of the work, past the spacer/standoffs (untouched) and into the spindle flange opening (not untouched). A verboten subject that one! Don’t anyone EVER bring it up again!

Tom


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## mikey (Feb 11, 2017)

I smiled twice this morning - thanks, Tom!


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## Hukshawn (Feb 11, 2017)

To be fair... I only kissed the jaw. One impact, under manual power. Just .001" past the mark.... 
Odd shaped plate in the 4 jaw boring an opening. Didn't notice one of the jaws was just peeking through the edge of my hole.


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## 4GSR (Feb 11, 2017)

My last blunder I can recall was similar, was a threading tool that held the triangle shaped insert on edge.  TNMA I recall?  Well anyway threading up to a shoulder, cutting a 1"-8 thread, yes there was a thread relief, but running at 160 RPM, didn't give you much time to disengage the half nuts and wam!  Pushed the work piece up into the chuck and side swiped the tool and pretty much wiped the insert off and destroyed the tool holder.  Had to buy another one at about $100 a pop!  This happen on a 16" Axelson with a CA size tool post and over 7-1/2 HP doing the damage!


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## 4GSR (Feb 11, 2017)

Another goof I did was run a 3/4" diameter end mill into the work piece, rapidly hand cranking the table, and bam! Snap off that end mill like it was nothing.  Old heavy 9-J Gorton mill didn't miss a beat and kept on running!


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## Hukshawn (Feb 11, 2017)

Jeez... Ida probably crapped my pants...

Edit, referring to the lathe crash.


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## RJSakowski (Feb 11, 2017)

Shawn, you have discovered one of the major drawbacks of using a DRO.  While they are convenient to use, they take your attention away from the work.  Kind of like texting while driving.


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## brino (Feb 11, 2017)

Hukshawn said:


> One impact, under manual power. Just .001" past the mark....



Does anyone else hear Maxwell Smart saying "Missed it by that much!"
-brino


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## wawoodman (Feb 11, 2017)

We need a "big owie" smiley!


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## Mach89 (Feb 11, 2017)

I managed to stall out the mill at work with a 1" end mill. Was going to make a facing cut using the Y axis power feed. Well, the Y power feed and the one for raising the table are pretty close together. I grabbed the wrong one and rapid traversed the table up, shoving the part hard against the endmill. I had the spindle in high gear, as slow as it would go (only because low gear is screwed up) and it came to a belt screeching stop. But it didn't break the endmill.

Sent from my SAMSUNG-SM-G891A using Tapatalk


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## 4GSR (Feb 11, 2017)

Hukshawn said:


> Jeez... Ida probably crapped my pants...
> 
> Edit, referring to the lathe crash.



Believe me, you react super fast! Then crap later!


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## Hukshawn (Feb 11, 2017)

I've considered rigging up some kind of e-stop brake. Currently I only have the paddle switch for forward/reverse.
When you're crapping your pants there can't be enough e-stops around... I know this from 15 years of factory work on production lines prone to crashing, even with e-stops every 10 feet, there's never one close enough.


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## 4GSR (Feb 11, 2017)

Even on newer lathes equipped with foot brakes, And I've operated a few over the years, you still can't react fast enough to push your foot against the foot brake to stop the lathe!  The nice thing about the Axelson lathe, you can reach up and grab the clutch lever and shove it into neutral or reverse quicker than fumbling around hitting the foot brake.  Your mind is trained to work with your hands when operating the lathe.  When you try to throw in your feet to maneuver a lever for a sudden stop, your mind is not fast enough to react because you mind is concentrating on hand movements not foot movements at that split moment.  And if you are  like me, with rheumatoid Arthritis in my legs, I don't react and move like I used to.  So those e-stops spaced every ten feet apart won't do a thing for me but look pretty on their mounts!


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## Hukshawn (Feb 11, 2017)

Fair enough. The line I ran was 100~ feet long and employed 6 people. It was composit spiral winding. Cardboard tubes basically. A backstand with 15 rolls of paper, the winder where all the paper gets wrapped around a mandrel (my job/operator), an automated cutter, and several packers. 
On my winder, myself and the manager set up a trip line e-stop under the machine, instead of stepping on something you only had to kick your foot forward. I was quick with that. Snapped the line off countless times kicking it too hard (hard not to get mad when someone blew the line up cause of a dumb mistake) 
Over the years, the kick line remained, but we had set up light curtains around the drums. Major in-line running pinch points from a winding belt. It was easy to stop the machine by throwing your hand past that too. 

In any event, any addition of a panic button on my machine would be an improvement over the nothing I currently have. The circuit is the easy part, figuring out how to brake the motor/spindle is another story...


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## 4GSR (Feb 12, 2017)

Hey, I've thought about a trip line setup on the lathe. 

Let it trip when your body gets about halfway around the chuck.

But seriously, it's a thought in the back of my mind to do so some day.  Just trying to figure out a position to  put it in.

One thing I did on a lathe many years ago.  I installed a Warner clutch-brake module on the input shaft of the lathe.   I put the push button control on the right side of the apron so you could slap the stop button quickly.  Worked out nice.  Pretty expensive to do today in the home shop environment.


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## Hukshawn (Feb 12, 2017)

4gsr said:


> Let it trip when your body gets about halfway around the chuck



Oh we had that covered too. There's a limit switch with a 4" stick on it positioned right above the mandrel in the infeed area. So if you got tugged in your body would hit it. It had only ever been used once... a female operator was wrapping the paper around the mandrel on setup/startup, her hand got caught. Took the tips of her fingers off before the machine stopped... but that's what happens when you put your hands where they don't belong. Never happened before or since, in 105 years of the company's history...


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## Hukshawn (Feb 12, 2017)

I'd take suggestions on how to brake the movement if anyone has any. I don't think I'm interested in changing the motor out for one with a brake. Too expensive. Personally, I'm thinking of something along the lines of a bicycle brake disc/caliper design, with a latching electric caliper of some kind......
Thoughts?


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## francist (Feb 12, 2017)

Wonder if a solenoid would have enough throw. Fooled around with bikes alot and the caliper brakes don't require much movement to draw tight. Whether they would have enough clamping force to do anything is another matter. Asco Red Hat solenoids are pretty reliable.

-frank


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## sanddan (Feb 12, 2017)

RJSakowski said:


> Shawn, you have discovered one of the major drawbacks of using a DRO.  While they are convenient to use, they take your attention away from the work.  Kind of like texting while driving.



That's one reason why I use an indicator for a carriage stop instead of the DRO. I like the feedback of the needle sweeping up to zero.

Now, lets not talk about busted parting tools! I have several on my personal wall of shame.


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## mksj (Feb 12, 2017)

Why not just set up your hard stop if you have a feed clutch? I always do this even with an electronic stop system, I always assume something is going to fail or at my age a brain fart (like honey what are you cooking me for dinner, turn head .....bam destroyed insert).


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## Bill Gruby (Feb 12, 2017)

If I know I am going to bore thru and come close to the jaws I use a sacrificial plate between the jaws and the part to be bored.

 "Billy G"


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## Hukshawn (Feb 12, 2017)

I don't have a carriage stop. Now that I have a mill that's on the project list. I always use the clutch. If I'm boring and I know the hole is smaller than the bore of the chuck I don't usually worry about spacers. The part was the motor mount for the belt conversion kit


Narrow in the middle. The chuck jaw in the middle was a bit closer into the center than I realized.


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## Hukshawn (Feb 12, 2017)

francist said:


> Wonder if a solenoid would have enough throw. Fooled around with bikes alot and the caliper brakes don't require much movement to draw tight. Whether they would have enough clamping force to do anything is another matter. Asco Red Hat solenoids are pretty reliable.
> 
> -frank


I was also thinking about pneumatic. My 60 gal compressor is always charged. So, there's always air available. I also have a valve solenoid. It has liquid fittings on it, but it's also rated for air and gas. So, all I'd  have to sort out is the actual brake


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## 4GSR (Feb 12, 2017)

Just think, air brakes!  like on a truck.  Love the sound they make.


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## Hukshawn (Feb 12, 2017)

PPPFFFFFSSSSHHHHHHHHHHH. lol


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## Hukshawn (Feb 13, 2017)

Well there it is...
If you look closely at the last picture, you can see the line where the new piece is threaded onto the old piece.
I'm glad I salvaged this...


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## intjonmiller (Feb 14, 2017)

I had my first such contact this week, but it really confused me because I knew I had done a dry run to make sure my full cut could be made without the carriage or anything on it running into the chuck. But something was definitely hitting. The fact that it was but I couldn't yet figure out what it was threw me off and made it harder to remember where the power switch and carriage feed lever were. Turns out I ran into the top of the saddle with the exterior-clamping jaws extended just far enough to reach. During my dry run I must have only spun the chuck before the carriage was over that far. Lesson learned, and there's a small scar to remind me. I'm glad this came without a hard collision or anything more than hardened steel jaws gradually scraping against an inclined cast iron surface.


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## 4GSR (Feb 18, 2017)

Amazing the damage a harden chuck jaw can do to cast iron parts of an lathe!  

Chewed up compound slides!  Ruts on the saddle and bed ways. I've seen them all, and even caused a few myself over the years.


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## Hukshawn (Feb 18, 2017)

Glad to say I have yet to smash the chuck on the carriage. 
But, I have, however, dropped the 6" 4 jaw on my hand unscrewing it from the spindle... I suppose better bruise my hand than damage the ways.....


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## Downunder Bob (Feb 18, 2017)

Hukshawn said:


> Don't run the boring bar into the chuck jaws on the end of the hole cause you're watching the dro and not the work...
> 
> View attachment 226046



That reminds me of why I don't have a DRO. I always thought "Hobby Machining" was all about doing it manually, the original way, you know hands on. But I guess there will always be those who want explore new territories, like DRO's, CNC and all sorts of other tricks. One should always have, and use a carriage stop  I'm thinking of designing one that will trip the feed. But too many other things to do at the moment.

BTW. I haven't had a chuck or cutter crash since I was an apprentice, but I did have a few back then. Fortunately our Toolroom Foreman was a very wise and kind person, after a crash he would discuss the reasons for the crash with us, bringing all the apprentices together for a show and tell. while the poor victim was very embarrassed he was kind and helped us to understand all the inherent dangers of all the machines we had in our shop, and they were many. I have often felt since those days that I and my fellow apprentices (all 8 of us) were very lucky in that we had  a very diversified training under the eye of a great foreman and his 3 leading hands plus all the toolmakers in the shop, usually 12 to 15 of them


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## Bob Korves (Feb 19, 2017)

My lathe has a foot brake, and it is pretty useless like the other controls when something unexpected happens.  By the time you get it stopped it has probably already bashed something pretty good.  However, the foot brake is perfect when you are anticipating needing to use it.  I have used it for metric internal threading tight up to a shoulder, leaving the half nuts engaged.  No problem.  My foot brake stops the spindle instantly if I have my foot resting on it and am mentally geared up to use it, even at higher speeds.  I occasionally find it really useful.


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## darkzero (Feb 19, 2017)

Speaking of foot brakes, I've seen some lathes (imports) that have a foot pedal connected only to a cut off switch, all it does it cut power to the spindle & does not actually have a physical brake on the spindle. I've always wonder what's the point in that setup?

My lathe does have a real foot brake, cuts spindle power & has a physical drum brake inside the spindle pulley. I love having a foot brake. But I use it only for convenience, I've never had to use it to try & prevent a crash.


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## utterstan (Feb 19, 2017)

I missed it by that much LOL to funny


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## The Liberal Arts Garage (Feb 19, 2017)

Make a simple box , bandsaw or whatever the top, suitable for lathe  and
Chuck so that the chuck only drops 3/8" or
so. Install or remove chuck safely with twenty minutes invested. ......BLJHB.


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## petertha (Mar 18, 2017)

What I try to do beforehand to protect myself is set my boring tool max depth & then use my homebrew stop which limits any further carriage travel. Actually I have 2 of these so I can put one on the other side of the carriage like when you have to bore a recess groove within 2 limits. You don't want to drive into them under power & they don't shut anything off. I just power feed until close & then traverse in my hand until the carriage kisses the stop, then repeat.


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## Fozzy Bear (Mar 19, 2017)

Hukshawn said:


> Don't run the boring bar into the chuck jaws on the end of the hole cause you're watching the dro and not the work...
> 
> View attachment 226046


Yeah... It's one I've done too a long time ago.  Once you've done it for the first time you never do it again.

Best Regards,
Fozz


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## Hukshawn (Mar 19, 2017)

petertha said:


> What I try to do beforehand to protect myself is set my boring tool max depth & then use my homebrew stop which limits any further carriage travel. Actually I have 2 of these so I can put one on the other side of the carriage like when you have to bore a recess groove within 2 limits. You don't want to drive into them under power & they don't shut anything off. I just power feed until close & then traverse in my hand until the carriage kisses the stop, then repeat.


Nice carriage stops. I need to make one for sure. I'd like to save the pictures to make some myself, but it won't let me save. Huh...


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## intjonmiller (Mar 19, 2017)

How are you viewing the photos? It's very easy in Tapatalk. Should be just as easy in a web browser. Tapatalk even lets me upload them directly to my Google drive where I store projects and stuff, to then be viewed later on a tablet.


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## petertha (Mar 19, 2017)

Hukshawn, here is link to my post with a bit more info. I could probably shoot out a PDF drawing too (or can these be posted?) but most of the dimensions will be lathe specific.
http://www.hobby-machinist.com/threads/not-another-a-lathe-stop-post.53425/#post-444842


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## Downunder Bob (Mar 19, 2017)

Bob Korves said:


> My lathe has a foot brake, and it is pretty useless like the other controls when something unexpected happens.  By the time you get it stopped it has probably already bashed something pretty good.  However, the foot brake is perfect when you are anticipating needing to use it.  I have used it for metric internal threading tight up to a shoulder, leaving the half nuts engaged.  No problem.  My foot brake stops the spindle instantly if I have my foot resting on it and am mentally geared up to use it, even at higher speeds.  I occasionally find it really useful.



I would love to have a foot brake, but unfortunately I would have had to go up a size to get one and that machine would not fit in the space I have, however as I said I'm thinking about making a carriage stop that will trip the feed, not a total solution, but a move in the right direction. I'm even thinking of how to fit a clutch/brake to the lathe, any ideas would be welcome. I'm thinking in terms of an automotive electric A/C clutch fitted to the motor. They can usually handle quite a few HP. and  a second one fitted to the pulley at the lathe end of the belt, set up as a brake. Could be set up with a button connected to a foot bar to simultaneously disengage the motor and apply the brake, a separate lever could be used just as a clutch. I like the idea of  a clutch very useful when doing a lot of stop/start work.


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## Downunder Bob (Mar 19, 2017)

Hukshawn said:


> Glad to say I have yet to smash the chuck on the carriage.
> But, I have, however, dropped the 6" 4 jaw on my hand unscrewing it from the spindle... I suppose better bruise my hand than damage the ways.....



It's always a good idea to place a wooden board on the bed under the chuck when removing, also useful when putting large heavy items in or out of the chuck.


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## TORQUIN (Mar 22, 2017)

One thought on emergency braking that comes to mind is the braking power of a VFD. I have mine set for gentle braking, but could ramp it up. I suppose it depends on the VFD, but they might be able to stop that motor very quickly. Rig up your emergency switches/stops to go through the VFD and it may work well.

Chris


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## Tozguy (Mar 22, 2017)

This is my carriage stop, but I do not recommend it.
It is very noisy!


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## petertha (Mar 22, 2017)

Tozguy said:


> This is my carriage stop, but I do not recommend it.


 That's the metric clone. Each of the inscribed rings is mm of interference, so just divide by 25.4 to get inches of crash


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## TRX (May 15, 2017)

Bah!

At least you didn't bore your MT3 headstock spindle straight for half an inch...

[oh, a squirrel!]


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## Groundhog (May 15, 2017)

francist said:


> Wonder if a solenoid would have enough throw. Fooled around with bikes alot and the caliper brakes don't require much movement to draw tight. Whether they would have enough clamping force to do anything is another matter. Asco Red Hat solenoids are pretty reliable.
> 
> -frank


In my experience it is easier/better to use a solenoid (or hydraulic or air cylinder) to hold a brake OFF. Use spring pressure to apply the brake. You can adjust the clamping force by the spring size (belville washer stack) and adjust the application rate by using a flow control valve when using a hydraulic or air cylinder.


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## 4GSR (May 16, 2017)

TRX said:


> Bah!
> 
> At least you didn't bore your MT3 headstock spindle straight for half an inch...
> 
> [oh, a squirrel!]


Oh, I have better than that!  I know you guys get tired of my stories, but we got to keep this trade going.

Dad told me of a man, wasn't him, working on night shift, was running a old lathe.  He was spade drilling a hole in a piece of iron, I'm guessing somewhere around 3" in diameter.  He doze off, next thing he wakes up and the chuck and piece of iron is just sitting there not turning on drill bar.  The lathe was still running.  He had bored thru the piece of iron, thru the chuck into the spindle until the part holding the chuck on parted off!  What a mess he created!

Well, being a oilfield machine shop, they were always fixing someone's mess up.  The man bored a box tool joint connection in the spindle.  Then on another lathe, made a pin connection to fit the freshly made one in the spindle.  Made it up in the spindle, finished the outside to fit the chuck. (I assume the original spindle was threaded as most older machines were made that way) And threaded the chuck on and went about his business like nothing happen.  Don't know if the boss ever found out either!

Much for my story telling for the day.

Ken


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## benmychree (May 16, 2017)

In an extreme case, I remember the story about a guy at Mare Island Navy Yard who had a job boring a long hole, when suddenly the chuck fell off; he had continued his cuts until he bored all of the spindle away; I think the story went that when this happened, he put his tools away, picked up the tool box and left the premises (permanently).


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## coolidge (May 16, 2017)

When your brand new end mill starts smoking just let the CNC mill continue while cussing it loudly...later switch the mill spindle from reverse to forward.


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## Downunder Bob (May 16, 2017)

4gsr said:


> Hey, I've thought about a trip line setup on the lathe.
> 
> Let it trip when your body gets about halfway around the chuck.
> 
> ...



I don't suppose you've got any pics or notes on the install..


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## 4GSR (May 16, 2017)

bobshobby said:


> I don't suppose you've got any pics or notes on the install..


No.  I never thought to take pictures of the conversion back then.  I did this back around 1978 and the lathe was sold in 1996.  

If your familiar with the old Warner clutch brake setup that was shaft mounted, that is basically what I used.  I don't even remember what size clutch-brake that I used.  I remember doing a layout drawing on paper to get the mounting dimensions correct along with making a stub shaft to extend the input shaft length coming out of the headstock.  Sorry I was not able to come up with anymore than that.

Ken


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## Tozguy (May 17, 2017)

benmychree said:


> In an extreme case, I remember the story about a guy at Mare Island Navy Yard who had a job boring a long hole, when suddenly the chuck fell off; he had continued his cuts until he bored all of the spindle away; I think the story went that when this happened, he put his tools away, picked up the tool box and left the premises (permanently).



I felt vulnerable only having a red mushroom panic button for emergencies that I might not be able to reach quickly enough so I installed a foot operated trip wire early in my adventure into turning. The system is cobbled to act on a power switch and triggers a homemade braking mechanism. It works but it does not give me any more comfort. It made me realize that there is no substitute for vigilance and awareness. The wisdom in the above quote is that if you are not on your game in machining you should be somewhere else.

The few 'surprises' I have had operating the lathe prove that things happen so fast, chances are slim the panic stops will prevent serious injury or damage to the lathe, even if you manage to operate them. So they are there but I do not depend on them at all. I have never found out (yet) for myself how useful brakes might be in panic situations so if you have any personal experience to share I am all ears.


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## Downunder Bob (May 17, 2017)

4gsr said:


> No.  I never thought to take pictures of the conversion back then.  I did this back around 1978 and the lathe was sold in 1996.
> 
> If your familiar with the old Warner clutch brake setup that was shaft mounted, that is basically what I used.  I don't even remember what size clutch-brake that I used.  I remember doing a layout drawing on paper to get the mounting dimensions correct along with making a stub shaft to extend the input shaft length coming out of the headstock.  Sorry I was not able to come up with anymore than that.
> 
> Ken


Thanks Ken, no I'm not familiar with them. Although it sounds something like what I had in mind. At this stage a lot of guys are saying I should forget it and convert to 3Ph with VFD, and I guess I could I already have 3Ph on the property I would only need to bring it around to the other side of the garage a run of about 20m. Buy and fit a suitable 3Ph motor, and VFD, sounds all very simple but I've got no idea where to start.

I'm a bit confused about this VFD stuff, because I've always believed that if you run a motor on a higher phase yes it will run faster but will probably over heat, And if you run it on a lower frequency it will run slower but also lose torque and overheat, so i'm still in the dark.


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## Bob Korves (May 17, 2017)

bobshobby said:


> Thanks Ken, no I'm not familiar with them. Although it sounds something like what I had in mind. At this stage a lot of guys are saying I should forget it and convert to 3Ph with VFD, and I guess I could I already have 3Ph on the property I would only need to bring it around to the other side of the garage a run of about 20m. Buy and fit a suitable 3Ph motor, and VFD, sounds all very simple but I've got no idea where to start.
> 
> I'm a bit confused about this VFD stuff, because I've always believed that if you run a motor on a higher phase yes it will run faster but will probably over heat, And if you run it on a lower frequency it will run slower but also lose torque and overheat, so i'm still in the dark.


Overheating has more to do with load vs. cooling capacity than speed.  A motor can be turning over very slowly, with the fan moving very little air, without problems if the load is small enough for the motor do dissipate the heat through radiation and natural convection, or short run duration.  At high speeds, the typical cooling fan also puts out more air, to a point, and the heat load is also highly dependent on output load.  A motor idling at very high speed, without a load, is pretty easy to keep cool.  I do not experiment with over speeds of more than 10% on my old surface grinder, with light loads, and only apply very light loads at low speeds, for short duration.  It does not pay to push a motor too hard, or to let it overheat.  Inverter rated motors and others designed for that kind of work can take wide ranges of speeds and loads without problems.


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## benmychree (May 17, 2017)

4gsr said:


> No.  I never thought to take pictures of the conversion back then.  I did this back around 1978 and the lathe was sold in 1996.
> 
> If your familiar with the old Warner clutch brake setup that was shaft mounted, that is basically what I used.  I don't even remember what size clutch-brake that I used.  I remember doing a layout drawing on paper to get the mounting dimensions correct along with making a stub shaft to extend the input shaft length coming out of the headstock.  Sorry I was not able to come up with anymore than that.
> 
> Ken


I had the Warner electric brake setup on one of my 19" swing Regal Leblonds, and it worked quite well, both in forward and reverse rotations when the lever is moved to the center position, but keep in mind that these would never do on a lathe with threaded spindle; the sights and sounds of a chuck unthreading and falling down between the ways is never a good thing.  It has nearly happened on my present 19" with threaded spindle, I use reverse via a drum switch sometimes to slow the spindle down to a stop, and have had it thread off partially, but have caught it with a shot of forward rotation and avoided having the chuck fall off.


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## Silverbullet (May 18, 2017)

4gsr said:


> Believe me, you react super fast! Then crap later!


Nope as soon as YA here the screaming of the lathe. Ouch


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## bfd (Jun 29, 2017)

during my apprenticeship my boss gave me a 3/8" 6" long solid carbide indexable tip boring bar. at home I bottomed it out I now have a 3/8" dia 3.5" long boring bar and a small length of solid carbide. went to a toolstore to replace it and found out a new one cost 300 dollars. sad day don't bottom out the boring bar. bill


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## Downunder Bob (Jun 29, 2017)

bfd said:


> during my apprenticeship my boss gave me a 3/8" 6" long solid carbide indexable tip boring bar. at home I bottomed it out I now have a 3/8" dia 3.5" long boring bar and a small length of solid carbide. went to a toolstore to replace it and found out a new one cost 300 dollars. sad day don't bottom out the boring bar. bill




That's one way to learn.


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## Downunder Bob (Jun 29, 2017)

Hukshawn said:


> Glad to say I have yet to smash the chuck on the carriage.
> But, I have, however, dropped the 6" 4 jaw on my hand unscrewing it from the spindle... I suppose better bruise my hand than damage the ways.....


I always like to place a piece of wood across the ways when removing or installing a chuck also when fitting large heavy objects into a chuck, and yes, always keep your hands out of the way.


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## KBeitz (Feb 26, 2020)

The reason a VFD does not over heat the motor is because motor heating 
is mostly caused by slip. Motor lagging behind phase.  The VFD changes the
timing of the phase. 

Boring bar mishap...
I've hit my chuck a few times but my chuck jaws is so hard the cutter squeaks
when the cutter hits it and does not hardly even leave a mark. I have one of the 
first large Grizzly lathes made back in 1987. It's been a good one.


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## Mini Cooper S (Feb 26, 2020)

Years ago when we had our manufacturing business, I was on the advisory board for a local tech collage. In one of our meetings, one of the schools instructors made the comment "There's nothing worse than seeing a student crash a machine." To which I replied, "Oh yes there is, PAYING someone to crash your machine!" 

Richard


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## stuarth44 (Feb 26, 2020)

Hukshawn said:


> Don't run the boring bar into the chuck jaws on the end of the hole cause you're watching the dro and not the work...
> 
> View attachment 226046


my new---old--Cazeneuve, has no marks on the original chucks, not bad for 1975 lathe today unpacked the smaller steady, the big un can hardly lift and the traveling steady


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