JB

Joe Barta

12/12/2005 2:51 AM

Cutter knife through chest

For the WTF file...

=================================================
From: http://www.mass.gov/dph/bhsre/ohsp/facefacts/facev21.htm

Woodworker Dies When Struck by Tool Knife Launched from Overarm Router

A 32-year-old woodworker was fatally injured at work when a steel tool
knife was propelled from a rosette cutter. The cutter was installed in
an overarm router. The steel tool knife penetrated a polyacrylic sheet
(trade name--Plexiglass) shield and then penetrated and exited his
chest, sub-sequently ricocheting off the wall before finally landing.
The victim was an experienced wood-worker, whose job also included
tool grinding and setup of spindle moulders.

The knife, measuring approximately 1-5/8 inch square, was part of a
cutter head assembly which had been previously used on a drill press
at much lower cutting speeds. It was custom designed and built for the
drill press, not for the router which is run at much higher speeds. At
the time of the incident, the router was set for 20,000 rpm and was
being used to make custom rosettes. The maximum permissible speed was
not indicated on the cutter head, and there were no written procedures
for its use (e.g., the recommended cutting tool speed). The knife was
held in the 4-3/4" diameter cutter head by flat shims and set screws.
The set screws could not counteract the centrifugal forces generated
by the high-speed rotation.
=================================================


Now, for shits and giggles I made the following calculations. I was
wondering, using the router speed and cutter diameter, what might have
been the speed of that cutter as it sailed towards it's non-thinking
victim. (Granted, I'm sure there are more complex mathematics required
to calculate this accurately... but this is good enough for my
amusement ;-)

20000 rpm
4.75" dia bit

bit circumferance = 4.75 * pi = 14.92"

20000 rpm/60 = 333.33 rounds per second

333.33 * 14.92" = 4974.19 inches per second

4974.19 /12 = 414.52 feet per second

414.52 * 60 = 24870.94 feet per minute

24870.94 * 60 = 1492256.51 feet per hour

1492256.51 / 5280 = 282.6 miles per hour

So, according my amateur calculations, that cutter blew through his
chest at 283 MPH!

Moral of the story? Well.... if you have to ask ;-)


This topic has 37 replies

DD

David

in reply to Joe Barta on 12/12/2005 2:51 AM

11/12/2005 7:32 PM

The Visitor wrote:

> But you get such a smooth finish at the higher rpms?
>
Not when the tool flies apart! :) You don't run a rosette cutter at
20,000RPM! Tell me you know better...

Dave

Gg

"Genedoc"

in reply to Joe Barta on 12/12/2005 2:51 AM

12/12/2005 8:51 AM

Hmmm, the Bullseye hand loads for my 45 behind a 110grain slug was just
over 800fps so he got hit by a slow 45cal bullet, Speed kills is one
moral..Take care...
David

Js

"JLarsson"

in reply to Joe Barta on 12/12/2005 2:51 AM

12/12/2005 11:46 AM


Joe Barta wrote:

{sad story about power tool ignorance/abuse snipped}
>
> So, according my amateur calculations, that cutter blew through his
> chest at 283 MPH!
>


I think you have just re-defined "terminal velocity".

Ds

"DonkeyHody"

in reply to Joe Barta on 12/12/2005 2:51 AM

12/12/2005 7:18 PM


George E. Cawthon wrote:
> In this case it wasn't speed that killed it was
> weight.

"For the cliff is all right, if you're careful," they said,
"And, if folks even slip and are dropping,
It isn't the slipping that hurts them so much
As the shock down below when they're stopping."
- from "A Fence or an Ambulance" by Joseph Malins

DonkeyHody

Ds

"DonkeyHody"

in reply to Joe Barta on 12/12/2005 2:51 AM

12/12/2005 7:18 PM


George E. Cawthon wrote:
> In this case it wasn't speed that killed it was
> weight.

"For the cliff is all right, if you're careful," they said,
"And, if folks even slip and are dropping,
It isn't the slipping that hurts them so much
As the shock down below when they're stopping."
- from "A Fence or an Ambulance" by Joseph Malins

DonkeyHody

Gg

"Genedoc"

in reply to Joe Barta on 12/12/2005 2:51 AM

13/12/2005 8:47 AM

lrod

I think it was a "Senior" moment mixing my 270 varmint load bullets
with the 45. Been a long time since I was doing combat pistol matches.
You can't mess with F=MA, it was the M as a post stated that pushed
that F way up..
David

d

in reply to Joe Barta on 12/12/2005 2:51 AM

16/12/2005 5:56 AM

Actually it's the dissipation in the body of the stored energy that
does it. This is proportional to the square of the velocity.

Gee, what was this guy thinking?

Gg

"Genedoc"

in reply to Joe Barta on 12/12/2005 2:51 AM

17/12/2005 3:10 PM

Sure do, quite a few years back, even had a link to some gory news
photos. It was a big bandsaw. Merry Christmas all. David

LT

"Leif Thorvaldson"

in reply to Joe Barta on 12/12/2005 2:51 AM

16/12/2005 11:10 AM


<[email protected]> wrote in message
news:[email protected]...
> Actually it's the dissipation in the body of the stored energy that
> does it. This is proportional to the square of the velocity.
>
> Gee, what was this guy thinking?


====>The worst one I can remember is the guy who committed suicide by
bandsawing himself in half!! Anyone remember that?

Leif

LT

"Leif Thorvaldson"

in reply to Joe Barta on 12/12/2005 2:51 AM

16/12/2005 5:01 PM


"Dave Hinz" <[email protected]> wrote in message
news:[email protected]...
> On Fri, 16 Dec 2005 14:46:04 -0500, Lee Michaels
> <leemichaels*nadaspam*@comcast.net> wrote:
>>
>> "Leif Thorvaldson" <[email protected]> wrote in message
>> news:[email protected]...
>
>>> ====>The worst one I can remember is the guy who committed suicide by
>>> bandsawing himself in half!! Anyone remember that?
>
>> How about those retards who blow up people by "gooseing" them with an air
>> hose?
>
> Google for "scrotum self-repair". Or maybe you don't want to. Involves
> moving machinery and staples.

===>Errrh, Dave. Just what prompted you to research "scrotum self-repair?"
*G*

Leif

bR

[email protected] (Robert Bonomi)

in reply to Joe Barta on 12/12/2005 2:51 AM

19/12/2005 2:26 PM

In article <[email protected]>,
Joe Barta <[email protected]> wrote:
>noonenparticular wrote:
>
>> ha. many moons ago.... funny....
>>
>> he made a pun.
>>
>> jc
>
>I did? What was the pun?

You had the cheeks to say 'moon'. It cracked-up Joe.
>
>(I need to start worrying when people laugh at what I say when I
>wasn't even trying to be funny ;-)

You didn't mean it that way, but he read it as the 'drop trousers in public'
act.

DD

David

in reply to Joe Barta on 12/12/2005 2:51 AM

11/12/2005 7:02 PM

Joe Barta wrote:

> For the WTF file...
>
> =================================================
> From: http://www.mass.gov/dph/bhsre/ohsp/facefacts/facev21.htm
>
> Woodworker Dies When Struck by Tool Knife Launched from Overarm Router
>
> A 32-year-old woodworker was fatally injured at work when a steel tool
> knife was propelled from a rosette cutter. The cutter was installed in
> an overarm router. The steel tool knife penetrated a polyacrylic sheet
> (trade name--Plexiglass) shield and then penetrated and exited his
> chest, sub-sequently ricocheting off the wall before finally landing.
> The victim was an experienced wood-worker, whose job also included
> tool grinding and setup of spindle moulders.
>
> The knife, measuring approximately 1-5/8 inch square, was part of a
> cutter head assembly which had been previously used on a drill press
> at much lower cutting speeds. It was custom designed and built for the
> drill press, not for the router which is run at much higher speeds. At
> the time of the incident, the router was set for 20,000 rpm and was
> being used to make custom rosettes. The maximum permissible speed was
> not indicated on the cutter head, and there were no written procedures
> for its use (e.g., the recommended cutting tool speed). The knife was
> held in the 4-3/4" diameter cutter head by flat shims and set screws.
> The set screws could not counteract the centrifugal forces generated
> by the high-speed rotation.
> =================================================
>
>
> Now, for shits and giggles I made the following calculations. I was
> wondering, using the router speed and cutter diameter, what might have
> been the speed of that cutter as it sailed towards it's non-thinking
> victim. (Granted, I'm sure there are more complex mathematics required
> to calculate this accurately... but this is good enough for my
> amusement ;-)
>
> 20000 rpm
> 4.75" dia bit
>
> bit circumferance = 4.75 * pi = 14.92"
>
> 20000 rpm/60 = 333.33 rounds per second
>
> 333.33 * 14.92" = 4974.19 inches per second
>
> 4974.19 /12 = 414.52 feet per second
>
> 414.52 * 60 = 24870.94 feet per minute
>
> 24870.94 * 60 = 1492256.51 feet per hour
>
> 1492256.51 / 5280 = 282.6 miles per hour
>
> So, according my amateur calculations, that cutter blew through his
> chest at 283 MPH!
>
> Moral of the story? Well.... if you have to ask ;-)
20,000 for a rosette cutter sounds like a recipe for disaster, which
coincidentally, it was! I don't have a rosette cutter (yet--thinking of
getting one soon), but I'd envision cutting at the slow speeds that a
Forstner bit requires. Am I wrong?

Just looked it up. 350RPM is recommended speed. sounds perfect to me. :)

Dave

DH

Dave Hinz

in reply to Joe Barta on 12/12/2005 2:51 AM

16/12/2005 7:50 PM

On Fri, 16 Dec 2005 14:46:04 -0500, Lee Michaels <leemichaels*nadaspam*@comcast.net> wrote:
>
> "Leif Thorvaldson" <[email protected]> wrote in message
> news:[email protected]...

>> ====>The worst one I can remember is the guy who committed suicide by
>> bandsawing himself in half!! Anyone remember that?

> How about those retards who blow up people by "gooseing" them with an air
> hose?

Google for "scrotum self-repair". Or maybe you don't want to. Involves
moving machinery and staples.

DH

Dave Hinz

in reply to Joe Barta on 12/12/2005 2:51 AM

17/12/2005 5:51 PM

On Sat, 17 Dec 2005 01:19:07 GMT, Joe Barta <[email protected]> wrote:

> It's an old story. I saw it first many moons ago... before there was a
> Google... before there was an Internet. It was on a piece of paper
> that was being passed around. And it's bizarre enough that 50 years
> from now the story will still be told... passed lovingly from father
> to son...

Allegedly true, but I haven't researched it.

ni

"noonenparticular"

in reply to Joe Barta on 12/12/2005 2:51 AM

17/12/2005 3:48 AM

ha. many moons ago.... funny....

he made a pun.

jc

"Joe Barta" <[email protected]> wrote in message
news:[email protected]...
>>> Google for "scrotum self-repair". Or maybe you don't want to.
>>> Involves moving machinery and staples.
>>
>> ===>Errrh, Dave. Just what prompted you to research "scrotum
>> self-repair?" *G*
>
> It's an old story. I saw it first many moons ago... before there was a
> Google... before there was an Internet. It was on a piece of paper
> that was being passed around. And it's bizarre enough that 50 years
> from now the story will still be told... passed lovingly from father
> to son...

DD

David

in reply to Joe Barta on 12/12/2005 2:51 AM

11/12/2005 7:43 PM

A. D. Coby wrote:

>>>the time of the incident, the router was set for 20,000 rpm
>
>
>>Just looked it up. 350RPM is recommended speed. sounds perfect to me. :)
>
>
> The forces which are trying to tear the cutter apart go up with the square of
> the speed. Thus at 20,000 rpm, the forces are over 3265 times what they
> would be at 350 rpm.
>
>
>
>
And I worry about the forces my arm exerts on a case cutter when slicing
open those damn blister packs! Every time I wield the CC, I think of
the stats of ER visits due to injuries suffered while opening such packages.

Dave

AD

"A. D. Coby"

in reply to Joe Barta on 12/12/2005 2:51 AM

12/12/2005 3:38 AM

>> the time of the incident, the router was set for 20,000 rpm

>Just looked it up. 350RPM is recommended speed. sounds perfect to me. :)

The forces which are trying to tear the cutter apart go up with the square of
the speed. Thus at 20,000 rpm, the forces are over 3265 times what they
would be at 350 rpm.



GE

"George E. Cawthon"

in reply to Joe Barta on 12/12/2005 2:51 AM

13/12/2005 1:17 AM

Genedoc wrote:
> Hmmm, the Bullseye hand loads for my 45 behind a 110grain slug was just
> over 800fps so he got hit by a slow 45cal bullet, Speed kills is one
> moral..Take care...
> David
>
110 grain 45cal bullet? sure you didn't mean 210
grain? 400fps is in the range of a bb or pellet
gun.

The revolving speed of the cutter may have been a
killer, but the actual killer was the weight and
size of that 1-5/8' square of metal.



In this case it wasn't speed that killed it was
weight.

TV

The Visitor

in reply to Joe Barta on 12/12/2005 2:51 AM

11/12/2005 10:19 PM

But you get such a smooth finish at the higher rpms?

JB

Joe Barta

in reply to Joe Barta on 12/12/2005 2:51 AM

17/12/2005 1:19 AM

>> Google for "scrotum self-repair". Or maybe you don't want to.
>> Involves moving machinery and staples.
>
> ===>Errrh, Dave. Just what prompted you to research "scrotum
> self-repair?" *G*

It's an old story. I saw it first many moons ago... before there was a
Google... before there was an Internet. It was on a piece of paper
that was being passed around. And it's bizarre enough that 50 years
from now the story will still be told... passed lovingly from father
to son...

JB

Joe Barta

in reply to Joe Barta on 12/12/2005 2:51 AM

17/12/2005 4:01 AM

noonenparticular wrote:

> ha. many moons ago.... funny....
>
> he made a pun.
>
> jc

I did? What was the pun?

(I need to start worrying when people laugh at what I say when I
wasn't even trying to be funny ;-)

LM

"Lee Michaels"

in reply to Joe Barta on 12/12/2005 2:51 AM

16/12/2005 2:46 PM


"Leif Thorvaldson" <[email protected]> wrote in message
news:[email protected]...
>
> <[email protected]> wrote in message
> news:[email protected]...
>> Actually it's the dissipation in the body of the stored energy that
>> does it. This is proportional to the square of the velocity.
>>
>> Gee, what was this guy thinking?
>
>
> ====>The worst one I can remember is the guy who committed suicide by
> bandsawing himself in half!! Anyone remember that?
>

How about those retards who blow up people by "gooseing" them with an air
hose?



Cs

"CW"

in reply to Joe Barta on 12/12/2005 2:51 AM

12/12/2005 4:23 AM

Massive chatter is more likely.

"The Visitor" <[email protected]> wrote in message
news:[email protected]...
> But you get such a smooth finish at the higher rpms?
>

FK

"Frank Ketchum"

in reply to Joe Barta on 12/12/2005 2:51 AM

12/12/2005 3:46 AM


"Joe Barta" <[email protected]> wrote in message
news:[email protected]...
> For the WTF file...
>
> =================================================
> From: http://www.mass.gov/dph/bhsre/ohsp/facefacts/facev21.htm
>

I mean if you just move out of the way as it explodes, you're fine ;)

sD

[email protected] (Doug Miller)

in reply to Joe Barta on 12/12/2005 2:51 AM

12/12/2005 11:59 AM

In article <[email protected]>, "Toller" <[email protected]> wrote:
>You guys can make fun of it all you want, but personally am making a point
>out of learning something from the tragedy.
>
>The report says it could have been prevented with polycarbonate instead of
>acrylic.

Yeah, well, maybe. But it *definitely* could have been prevented by the use of
the operator's brain.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

OL

Oleg Lego

in reply to Joe Barta on 12/12/2005 2:51 AM

16/12/2005 1:22 AM

The The Visitor entity posted thusly:

>But you get such a smooth finish at the higher rpms?

Well, it certainly finished him smoothly.

Rd

Robatoy

in reply to Joe Barta on 12/12/2005 2:51 AM

12/12/2005 1:54 PM

In article <[email protected]>,
"Toller" <[email protected]> wrote:

> You guys can make fun of it all you want, but personally am making a point
> out of learning something from the tragedy.
>
> The report says it could have been prevented with polycarbonate instead of
> acrylic. I was trying to decide between acrylic or polycarb lenses for my
> new prescription ski goggles (can't see the snow anynore...). You can bet
> your ass I have chosen polycarb. If a rosette cutter flies at me at 283mph
> while I am skiing, I am ready.

...or... if you're skiing at 283 MPH, and hit a branch with your eye...

TT

"Toller"

in reply to Joe Barta on 12/12/2005 2:51 AM

12/12/2005 5:12 AM

You guys can make fun of it all you want, but personally am making a point
out of learning something from the tragedy.

The report says it could have been prevented with polycarbonate instead of
acrylic. I was trying to decide between acrylic or polycarb lenses for my
new prescription ski goggles (can't see the snow anynore...). You can bet
your ass I have chosen polycarb. If a rosette cutter flies at me at 283mph
while I am skiing, I am ready.

JJ

in reply to "Toller" on 12/12/2005 5:12 AM

12/12/2005 9:20 AM

Mon, Dec 12, 2005, 5:12am (EST+5) [email protected] (Toller) claimeth:
<snip> The report says it could have been prevented with polycarbonate
instead of acrylic. <snip>

Wrong. It could have been "prevented" by lack of stupidity.

Using polycarbonate "might", or not, have kept him from being
killed.

Darwin Awards candidate.

Stupidity \Stu*pid"i*ty\, n. [L. stupiditas: cf. F. stupidit['e].] Latin
- clean up the gene pool



JOAT
A rolling stone gathers no moss...unless it's a hobby he does on the
weekends.

Sk

"Swingman"

in reply to Joe Barta on 12/12/2005 2:51 AM

12/12/2005 5:09 AM

"Toller" wrote in message

> I was trying to decide between acrylic or polycarb lenses for my
> new prescription ski goggles (can't see the snow anynore...).

Go in the summer then ... it's a lot cheaper.

--
www.e-woodshop.net
Last update: 11/06/05

Ld

LRod

in reply to Joe Barta on 12/12/2005 2:51 AM

13/12/2005 5:12 AM

On Tue, 13 Dec 2005 01:17:29 GMT, "George E. Cawthon"
<[email protected]> wrote:

>Genedoc wrote:
>> Hmmm, the Bullseye hand loads for my 45 behind a 110grain slug was just
>> over 800fps so he got hit by a slow 45cal bullet, Speed kills is one
>> moral..Take care...
>> David
>>
>110 grain 45cal bullet? sure you didn't mean 210
>grain? 400fps is in the range of a bb or pellet
>gun.

If I recall, the standard "military ball" full round nose round is a
230 grain bullet. And I think I recall loading 185 grain
semi-wadcutters back in my shootin' days. 110 grains seems awfully
small for a .45 slug. Wouldn't take much Bullseye to get that little
thing to 800 fps.


--
LRod

Master Woodbutcher and seasoned termite

Shamelessly whoring my website since 1999

http://www.woodbutcher.net

Proud participant of rec.woodworking since February, 1997

Ld

LRod

in reply to Joe Barta on 12/12/2005 2:51 AM

13/12/2005 5:12 AM

On Tue, 13 Dec 2005 01:17:29 GMT, "George E. Cawthon"
<[email protected]> wrote:

>Genedoc wrote:
>> Hmmm, the Bullseye hand loads for my 45 behind a 110grain slug was just
>> over 800fps so he got hit by a slow 45cal bullet, Speed kills is one
>> moral..Take care...
>> David
>>
>110 grain 45cal bullet? sure you didn't mean 210
>grain? 400fps is in the range of a bb or pellet
>gun.

If I recall, the standard "military ball" full round nose round is a
230 grain bullet. And I think I recall loading 185 grain
semi-wadcutters back in my shootin' days. 110 grains seems awfully
small for a .45 slug. Wouldn't take much Bullseye to get that little
thing to 800 fps.


--
LRod

Master Woodbutcher and seasoned termite

Shamelessly whoring my website since 1999

http://www.woodbutcher.net

Proud participant of rec.woodworking since February, 1997

FC

Fly-by-Night CC

in reply to Joe Barta on 12/12/2005 2:51 AM

16/12/2005 11:55 PM

In article <[email protected]>,
"Leif Thorvaldson" <[email protected]> wrote:

> The worst one I can remember is the guy who committed suicide by
> bandsawing himself in half!! Anyone remember that?

I do remember that but don't think I buy it. There wasn't blood spilled
all over the saw as I recall, and sawing a living person in half oughta
produce copious quantities of blood - at least that's how I put it out
of my mind.
--
Owen Lowe
The Fly-by-Night Copper Company
__________

"I pledge allegiance to the flag of the
Corporate States of America and to the
Republicans for which it stands, one nation,
under debt, easily divisible, with liberty
and justice for oil."
- Wiley Miller, Non Sequitur, 1/24/05

CT

Chuck Taylor

in reply to Joe Barta on 12/12/2005 2:51 AM

12/12/2005 6:23 AM

On Mon, 12 Dec 2005 03:46:14 GMT, "Frank Ketchum"
<[email protected]> wrote:

>
>"Joe Barta" <[email protected]> wrote in message
>news:[email protected]...
>> For the WTF file...
>>
>> =================================================
>> From: http://www.mass.gov/dph/bhsre/ohsp/facefacts/facev21.htm
>>
>
>I mean if you just move out of the way as it explodes, you're fine ;)


Easy. For a table saw, just stay out of the line of fire. For a
router, just stay out of the plane of fire.


--
Chuck Taylor
http://home.hiwaay.net/~taylorc/contact/

LM

"Lee Michaels"

in reply to Joe Barta on 12/12/2005 2:51 AM

12/12/2005 12:29 PM


"Chuck Taylor" <[email protected]> wrote in message
news:[email protected]...
> On Mon, 12 Dec 2005 03:46:14 GMT, "Frank Ketchum"
> <[email protected]> wrote:
>
>>
>>"Joe Barta" <[email protected]> wrote in message
>>news:[email protected]...
>>> For the WTF file...
>>>
>>> =================================================
>>> From: http://www.mass.gov/dph/bhsre/ohsp/facefacts/facev21.htm
>>>
>>
>>I mean if you just move out of the way as it explodes, you're fine ;)
>
>
> Easy. For a table saw, just stay out of the line of fire. For a
> router, just stay out of the plane of fire.
>
>
How would you do that?

Wouldn't you have to be horizontal and above the router bit??

Doesn't sound very practical.



CT

Chuck Taylor

in reply to Joe Barta on 12/12/2005 2:51 AM

12/12/2005 11:48 AM

On Mon, 12 Dec 2005 12:29:52 -0500, "Lee Michaels"
<leemichaels*nadaspam*@comcast.net> wrote:

>
>"Chuck Taylor" <[email protected]> wrote in message
>news:[email protected]...

>> Easy. For a table saw, just stay out of the line of fire. For a
>> router, just stay out of the plane of fire.
>>
>>
>How would you do that?
>
>Wouldn't you have to be horizontal and above the router bit??
>
>Doesn't sound very practical.


Tongue-in-cheek. It would be not just impractical but nearly
impossible--and potentially a serious danger all by itself.

And it certainly wouldn't stop a rosette cutter from flying apart when
it's misused.


--
Chuck Taylor
http://home.hiwaay.net/~taylorc/contact/

Cs

"CW"

in reply to Joe Barta on 12/12/2005 2:51 AM

12/12/2005 4:22 AM

Do as I do. Use the scroll saw.

"David" <[email protected]> wrote in message
news:[email protected]...
> >
> And I worry about the forces my arm exerts on a case cutter when slicing
> open those damn blister packs! Every time I wield the CC, I think of
> the stats of ER visits due to injuries suffered while opening such
packages.
>
> Dave


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