Re: [CAD_CAM_EDM_DRO] injuries from your machine?

> Have you suffered any injury in the use of your "homebuilt" or home
> retrofitted CNC, EDM, or DRO system? Has someone you "allowed" (or
> maybe DIDN'T allow) to use the machine gotten hurt?
>
> What type(s) of injury, and what have you done to prevent a
> recurrance?

I was not going to respond, but I figured this would be of some interest,
especially due to the pictures... This was at the shop, not on my home
machine, and it was a manual SB 10" lathe, not CNC, but nonetheless...

Just in case it isn't obvious, the attached photo is an X-ray of more than
1" of a drill which broke off in the back of my hand.

To some greater or lesser degree, the setup of the machine was partially
responsible for the incident. I was removing a part from a (stopped)
collet. As I reached for the collet closer, I accidentally hit the power
swith (located just a couple of inches away from the closer lever).

Surprised by the sudden spinning of the part, which I was expecting to drop
into my hand, I yanked my hand back, diagonally into the drill bit and chuck
in the tailstock. I was so startled, and yanked my hand back so quickly,
that the impact made a loud *thok* sound. Everyone in the shop heard it,
and assumed that I stuck my hand into a spinning 3 or 4 jaw chuck...
(*SOMBODY* on the list has had to have done that at least once)

Since I was pulling back away from the machine, the sideways force broke the
drill at the chuck. The drill had penetrated the back of my hand, and
almost came out between the pinkie and ring fingers. Made a little tent out
of the webbing between the fingers, but did not come through. Around the
entry point was a large blackish bruise (presumably from hitting the drill
chuck so hard).

Sorry I don't have any real pictures to show...

I believe that better ergonomics, is the key. The power lever at work is
long-ish, extending ebyond the housing for the switch, with a very light
action. Easily engaged by mistake. Not the typcial short lever you
typically see on a lot of other manual machines. The ease of accidentally
engaging the motor was compounded by the switch location (near the collet
closer lever).

FWIW, the power switch on my home SB is located below the bed, away from
anything else on the machine.

I kept this image as my desktop wallpaper on my notebook, as a constant
reminder not to go and do something stupid again... that and the scar from
the repair surgery which is slowly fading...

Steve
(Someday hoping to make both my home SB10 and Burke Millrite CNC)



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