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View Full Version : A jaw in the jaw - A NEAR MISS !



JoeCB
07-23-2012, 05:02 PM
Just a heads up warning... I almost had an "event" today in the shop. I chucked up a piece of 2-1/2 " round in my faithful 5 " Burnerd 6 jaw scroll chuck. All seemed OK as I tightened the chuck. Started taking a face cut and... surprise, the number 6 jaw flew out and into the wall, could just as well have been into my face.
Lesson to be learned; if one is near the capacity of the scroll, be darn sure that all the jaws are engaged. I don't believe that this condition would go unnoticed on the more common 3 jay chuck, but sure has the potential for an accident with a 6 jaw.

Joe B

armedandsafe
07-23-2012, 09:37 PM
As a newby to making chips, THANK YOU! I don't have a 6 jaw, but I will be setting up a 4 jaw for near-max diameter very soon.

Pops

Dr Stan
07-23-2012, 09:42 PM
will be setting up a 4 jaw for near-max diameter very soon.

Pops

With a 4 jaw it would be quite evident you did not have one jaw tightened assuming you dialed in the workpiece to run true. However, it is a good warning. I never had anything come out of a chuck, but did loose a gate from a valve on an adjustable angle plate mounted on a face plate a couple of times. Never did figure out what I did wrong.

KiddZimaHater
07-23-2012, 10:01 PM
TIP: I stamped the side of my chuck with '3.5' , which is the max diameter that can be safely gripped with my chuck.
Determine what your 'safe' diameter is, and stamp the side of yours.

jkilroy
07-23-2012, 10:18 PM
Oh yeah, this can happen with any scroll type chuck, one jaw can be totally free to move while the others are firmly gripped. One more reason why you NEVER stand in line with the chuck or work piece when turning on the lathe or engaging the clutch. If the work-piece is about to move, MOVE YOUR ASS OUT OF THE WAY until you are sure that everything is working smoothly.

vpt
07-23-2012, 10:24 PM
I nearly had the same happen awhile ago on the 4 jaw. I rotated the chuck before powering on and the jaw fell out.

Dr Stan
07-23-2012, 11:04 PM
I nearly had the same happen awhile ago on the 4 jaw. I rotated the chuck before powering on and the jaw fell out.

I stand corrected. jkilroy's advise is excellent.

John Stevenson
07-24-2012, 04:35 AM
Clumsy bastard.

browne92
07-24-2012, 11:17 AM
Clumsy bastard.

You HAD to know that was coming. :D

Mcgyver
07-24-2012, 01:29 PM
Probably missed you because you had the good sense to stay out of the line of fire ....so we'll call you the adroit clumsy bastard :D It's good practice to keep to the right of the chuck.

SmoggyTurnip
07-25-2012, 10:41 AM
Interesting topic. If I wanted to put a stamp on my chuck how would I decide what the max safe diameter is? If a jaw only has one tooth engaged is that safe ?