Screw cutting scare

[doubleboost]

I was buisy cutting a coarse thread on my bantam lathe .
It was only 20 mill long so i was cutting it by hand (gear box in neutral turning the chuck manually)
The job went very well the nut i was using for a pattern screwed in nice and tight .
The last thing to do was to face the job off.
I turned the tool post around set up the tool put the lathe in to gear then switched the power on .
The lead screw was still engaged. with the spindle running at 800 RPM the result was instantanius the tool crashed in to the chuck i hit the stop button and stood well back , the noise was sickening thank fully the damage was not to bad .
The job is scrap the tool finished and the chuck jaws maked (under pants well soiled)
It takes only a split second laps in concentration to turn a pleasure in to a disaster.
Regards
John

 

[Deanofid]

Glad you came out of it okay!

Now, swap out those nasty bloomers and have another go.

Dean

 

[rake60]

It's bound to happen if you do it long enough John.
Happy there was no personal injury result!

I did one better on an industrial lathe at work one day.
It was the very first time I had ever run it. I had received the usual training.

"Here's the power switch, this is the gear box for the chuck speeds, forward and reverse.
Feed lever here, feeds are are on that placard, See Ya."

OK, I got it.
Touch off, dial in a cut depth of .250, reach down and grab the threading half nut lever that
happens to be right next to the feed lever and give a firm jerk up to engage it.

Oops! that ain't right!
Somebody needs to call maintenance. There seems to something wrong with this
tool post alignment.
:hDe:

Yeah, we have all made boo boo's when threading.
Even if threading wasn't the original intent at all.

Rick

 

[bucketboy]

It Happens :


A few years ago I was using a very large milling, I was deburring the casting while the machine was in "auto" I placed the file on the knee, something I had done thousands of times, as the table continued to travel I would normally notice the file moving or hear it hit the floor as the table pushed it off the knee but not this time what I heared was a huge BANG and all the lights in the factory went out What I hadn't noticed was that the file was being pushed straight through the steel cover of a 415V 300amp electrical supply


The machine was OK

The file wasn't ;D


Bb

 

[John Rudd]

Apologies for posting this here too...Feel free to delete this if it infringes forum policy.

I must re-iterate the need for extreme vigilance when using a manual crank for threading...

Last night I needed to thread a piece of bar with an M6 thread, out came the hand crank that fits into the spindle of my Chester 9*20, it only needs a nip up with a 13mm A/F spanner and thats it sorted. Thread cut on the bar and I'm ready to clean up....

So power back on the lathe by resetting the Emergency Stop switch and away we go....( I should add that there are two further manual steps required to bring the machine to speed..)
There was a lot of noise and a tin of WD40 fell to the floor before I realised what was happening!!!

I some how managed to catch my left hand on the rotating crank, fortunately I was wearing some thin gloves else the damage may have been worse...

I hit the EM Stop before the machine had managed to build up too much speed......

In my haste to complete the job I forgot to remove the crank from the spindle much to my own suffering!!!

I might add, I usually remove the spindle drive belt to prevent me doing such stupid things, but this time I thought it was only a 2 min job to thread the bar.......

I'd have posted pictures of the injury to my left hand but thought it may have caused some distress, I leave it to your own imagination

Be warned gents, these things can bite real hard if you get it wrong..I've learned a lesson which could have cost me my fingers or worse..

I cant stress how conscious we need to be when operating machinery..

Please, Be Safe.....

John ( aka Fingers... )

 

[Huntinguy]

I had been running lathes in the shop for several years... same make and type... Boss put me on a new lathe... same instructions as you had... Well, years of pulling up on the lever to disengage the feed.... this lathe was down to disengage... Yep... pulled the part right out of the chuck... Funny now... wasn't then.........