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View Full Version : Unexpected danger from an AXA toolpost!



TheNutter
25th Dec 2019, 09:04 PM
Hi all,

I thought the I might share this in the hope that it is something that we might all learn from...

Recently I was machining a bronze casting for a 7 1/4 model locomotive chimney cap. This is a large hunk of bronze bored to fit over a 63mm stainless chimney and then with most of the outer surfaces compound curves. I spent a long time machining the curves with HSS tools that I ground to form. Doing the job involved a lot of tool changes but as I have an AXA quick change tool holder this presented no particular problem. I made these changes without stopping the spindle, something I have done on many hundreds of occasions.

On one occasion I released the tool carrier by giving the lever a flick with the palm of my right hand, the locking lever then spun around until it came into contact with the face of the chuck where it was hit by a jaw. This broke the lever off and sent it flying past my left ear. Something that I by no means enjoyed.

Fortunately there was no major damage and I was able to machine and re-thread the handle to fit.

I will however keep this well in mind from now on and either stop the lathe or move the carriage away before changing a tool carrier.

We live and we learn, if we are careful and fortunate.

Regards

Ian

pipeclay
25th Dec 2019, 11:08 PM
Should it be titled unexpected danger from not stopping spindle?

Michael G
26th Dec 2019, 07:01 AM
Maybe have a look at your set up. I just tried this with my QCTP and the lever goes from around 2:30 through to 7 o'clock when I'm standing in the normal operating position.
The way you have described it does sound hazardous - maybe install a stop to limit travel?

Michael

snapatap
27th Dec 2019, 09:15 AM
Never change tools with the spindle running, one slip and you are risking serious injury.

TheNutter
4th Jan 2020, 07:45 PM
Thanks Michael that is a good suggestion.

Regards

Ian

Borriss
11th May 2021, 08:07 PM
I remember in my apprentice days working on a lathe behind the "gun" turner. He replaced the tool post spanner with a piece of high tensile bar welded to a socket with the idea of speeding things up. While doing a tool change he whacked the said bar with the palm of his hand, this swung around and caught in the rapidly spinning 4 jaw chuck. Consequence: The momentum and force tore the whole compound and tool post from the cross slide which then went into orbit over his head and landed behind him on the floor. Luckily no injury except to his pride. This occurred on the afternoon shift and by morning the damage to the torn out bolt circle was brazed up and all put back together.
The guys nickname was tearar$e! He probably did that!
Borriss

eskimo
18th May 2021, 10:09 AM
Should it be titled unexpected danger from not stopping spindle?

you took the words out of my mouth

Its been drummed into into us from woodwork and metalwork in grades 6 and 7 to stop rotating devices before adjustments....that rule still applies today