Horror Stories About The Chuck Coming Off While Running Backwards

george wilson said:
The trouble with peeing on the electric fence might be that you would not be able to STOP!!!!:)

When I was about 7 years old,on the way home from school,I used to stop and look at the cows in a pasture. Leaned on the electric fence TWO times before I got it through my thick head NOT to do that! Gave me quite a jolt,too!!

There was a bull penned up across the street. I used to pull up grass and feed him every day. He was quite gentle,and glad to get the grass,as there was none in his pen. One day that bull got loose,and the men were running all over the place,yelling about that DANGEROUS bull being free!! I had had a very friendly relationship with that bull as far as I was concerned,though I had NOT tried getting in the pen with him.
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Back in the late '40s my older brothers convinced me to wet the electric fence as well. The fence was pulsed allowing a quick withdrawal!
 
An occurrence which frightened me many years ago happened to me with an old & beat up geared head lathe of about 14" center height, I was trying out the speeds to see all was well, (Never having seen this old machine running before) It, I found out later had a fairly worn register and screw thread on the spindle nose, + even more insidious a very vicious clutch.
Anyway I ran the damned old thing up to a speed on the higher range, Thought It is a bit fast to be running with the heavy chuck , forgot the nasty quick bite on the clutch, pushed the lever over to the stop position, The spindle stopped dead , & the inertia of the revolutions of the chuck kept it spinning , Off it came , fortunately missing me as it bounced on to the floor,

If you have not seen a machine working , care is essential , It would seem the turner who operated it, always stayed in the lower speed ranges, Like Felix the cat, I lost one of my nine lives!
 
I have a personal rule never to use the reverse feature except to run the carriage back to the starting point when cutting threads and only when using backgears so there isn't as much inertia involved. I have no doubt I could snap the chuck loose if I wanted to. I kinda like having 10 functional fingers. (and toes)
Mark S.
 
The place I apprenticed at, it was customary to snap lathes into reverse to stop the chuck. Another apprentice did this on our Jap toolroom lathe, we were a Southbend heavy shop, and the 6" chuck unscrewed, he put his hands up to protect himself or maybe catch the chuck, idunno but it bounced off the way and straight into his hand. He ended up with a sprained wrist from it and STILL continued to snap lathes into reverse to stop the chuck.

He also didn't wheel up the surface grinder wheel enough and after dressing the wheel, he wiped the mag chuck with his hand and got a nice zip across the back of his hand.
 
Many a South Bend lathe (and perhaps others) were built which included a drum switch and an instant reversing motor and nothing more than a threaded spindle. If running in reverse is so dangerous, what was this feature used for?
 
I witnessed an Albrecht chuck fly off a Clausing drill press. It was on an Albrecht MT2 arbor.
I explained to the shop foreman that we could get a new Albrecht with an integral Mt2 from Albrecht, free of charge.
We just cleaned it up and tapped it back on securely and back to work.
 
george wilson said:
The trouble with peeing on the electric fence might be that you would not be able to STOP!!!!:)

When I was about 7 years old,on the way home from school,I used to stop and look at the cows in a pasture. Leaned on the electric fence TWO times before I got it through my thick head NOT to do that! Gave me quite a jolt,too!!

There was a bull penned up across the street. I used to pull up grass and feed him every day. He was quite gentle,and glad to get the grass,as there was none in his pen. One day that bull got loose,and the men were running all over the place,yelling about that DANGEROUS bull being free!! I had had a very friendly relationship with that bull as far as I was concerned,though I had NOT tried getting in the pen with him.
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It's like that old story about the frog and the scorpion.
 
I have had a chuck start to come off when i turned on the lathe. This was on a Taig and I had just put the chuck on. I do not put them on very tight because they tend to get tighter and are sometimes hard to get off. don
 
dontrinko said:
I have had a chuck start to come off when i turned on the lathe. This was on a Taig and I had just put the chuck on. I do not put them on very tight because they tend to get tighter and are sometimes hard to get off. don
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I always tighten the chuck well for several reasons: 1. If the chuck isn't tightened, you will not get proper registration with the face of the spindle and runout will suffer. and 2. not fully tightening a threaded chuck will actually tighten it more. When you start to encounter some resistance, the chuck will spin slightly and the inertia will overtighten. Kind of like the way an impact wrench works. Finally, as has been observed, the chuck can unscrew during use and it doesn't necessarily mean running in reverse. If you have a large workpiece in the chuck, simply stopping the lathe can unscrew the chuck.
 
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