Question on chucks & a warning on lathe safety.

[colin branniganParticipant @colinbrannigan54160]

Accidents while operating a lathe……………way back in 1968 while attending night school, doing MECP 2 as part of my tool making apprenticeship, I was using a large Colchester lathe when my cow gown/brown coat caught in the lead screw and was ripped off me along with jumper, shirt, trousers and pants.

I stood there shocked, battered and naked except for my bike boots, one of the other students had hit the e stop on the wall which shut all machines down but the damage was done, I can only think as we were a poor family all my clothes were hand me downs and worn out which may have saved me from injury.

The lecturer was having a smoke in the stores with the technician at the time but he did go home to bring me some clothes so I could ride my bike home.

I am 67 now, been on the tools all my life, have all my fingers but one broken thumb (emery in lathe but I still do it), last year I set up a small machine shop in a garden shed containing Myford 7 Chinese miller, power saw, drill, welding to help with my passion for British Bikes when I do retire, I have a dozen bikes of varying age and size a 1927 Triumph W to a 1972 Triton.

I have been hovering here in the background for a while reading the posts and have my own views on tightening a Jacobs chuck I use two holes but on a three jaw on a lathe I use all three, and I can work in inches (American drawings) and metric European and Japanese drawings and metric is far easier

Many thanks for an excellent site

Colin

[MWParticipant @mw27036]

Posted by Carl Wilson 4 on 10/02/2017 09:30:20:
Was that the apprentices fault? No it was not. A case of a lack of adequate supervision.

Indeed, as my stated link shows, it doesn't really matter how much experience you have, an accident can happen to anyone.

I had a long time engineer make a mistake, when I was using the lathe he asked if he could "take over" for a quick job, so I left him to it and stood back to one side. He was trying to drill and tap a long length of thin plastic bar, with about 1 foot length sticking out the back of the spindle, he turned it up to 2.5k rpm and it just instantly snapped with a sharp crack, so quickly it happened it was already falling from the ceiling as it hit the roof of the factory, that's about 30-40 feet high. The cabinet I was immediately stood next to was a steel cabinet with a huge dent where it hit, if I had stood 1 foot to the left that would've hit me.

He was absolutely embarrassed of course, for this to happen as an apprentice myself was watching, but I didn't have any grudges about it, I didn't really want to report him either because I knew he was a good bloke.

Michael W

[Ian S CParticipant @iansc]

Another thing is with people using electronic speed control, particularly larger old lathes with cast iron chucks, DON"T over speed them, a burst chuck is something you never want to see, even if you do live after the burst.

Ian S C

[HopperParticipant @hopper]

Posted by Carl Wilson 4 on 10/02/2017 09:30:20:
Was that the apprentices fault? No it was not. A case of a lack of adequate supervision.

With one supervisor and 30 apprentices it would have been impossible for him to supervise everything that everyone did at every moment. The stands were there. We had been instructed in their use. The apprentice did not use it. As I am thinking back now, I believe one of the other apprentices may have walked past, looked at the spinning end of the 5/16" rod and out of curiosity, given it a bit of a slap, sending it off centre and centrifugal force took over rather rapidly from there. Luckily he was walking past teh end of the bar and so out of the firing line. His lucky day for sure. I've an idea he was the same apprentice who filled his cigarette lighter from the spigot on the bottom of the five gallon toluene barrel then stood there and flicked it to see if it worked, while his hand, sleeve and the surrounding area went WOOFA! Yes, it was his fault that time, I'm sure.

It's been my observation in various industries that accidents are usually caused by a combination of errors, or oversights, or shortcuts etc. Usually it takes three. So in the 5/16 bar instance, yes probably not enough supervision for 30 sixteen year olds turned loose on power machinery. Plus apprentice one fails to use the safety stand on thin bar protruding from the headstock. Plus apprentice two walks past and foolishly slaps the spinning bar off centre. Three factors combined to make an accident.

ISTR that in later years, they got a second instructor in the training centre so there would have been one on the shop floor at all times, theoretically.  And I am sure that in this day and age something more substantial than a tripod with a bit of pipe welded on top is used when feeding long bar into a headstock, as on capstan lathes (cnc these days I suppose) turning long lengths into mass produced small widgets. Of course, in this day and age, that car factory has been closed down and the building repurposed as a small business incubator centre where the biggest injuries are paper cuts.

 

Edited By Hopper on 10/02/2017 11:15:23

Edited By Hopper on 10/02/2017 11:18:19

[Neil WyattModerator @neilwyatt]

Hello Colin,

Welcome to the forum. Glad you (just) survived the 60s….

Neil

[Nick HulmeParticipant @nickhulme30114]

Posted by Michael-w on 10/02/2017 09:43:07:

Posted by Carl Wilson 4 on 10/02/2017 09:30:20:
Was that the apprentices fault? No it was not. A case of a lack of adequate supervision.

Indeed, as my stated link shows, it doesn't really matter how much experience you have, an accident can happen to anyone.

"Experienced" doesn't preclude "careless", "stupid" or a swathe of other inconvenient traits in the shop though. 

Different accidents will happen to different people, this is because most "accidents" are not such, they are in fact "Incidents" which were the entirely predictable results of a set of circumstances which the user could observe but could not comprehend as the source of an unwanted event.

Vanishingly few shop "accidents" would happen regardless of the operative asked to carry out a task under exactly replicated starting circumstances, the words "unwary", "unwitting", tired", "hurried" an even occasionally "drunk", "bone-stupid" or "drugged-up" all have far more of a place than "accident"

Aditionally we have a mass of people in this world who no longer wonder "how can I o that" and investigate but instead think "why wouldn't I be able to do that" and unwittingly dive right in with inadequate personal an technical resources, blissfully unaware until the wheels come off 😀

Edited By Nick Hulme on 11/02/2017 13:15:33

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