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  #1  
Old Fri 17 April 2009, 15:28
Alan_c
Just call me: Alan (#11)
 
Grabouw (Western Cape)
South Africa
Send a message via Skype™ to Alan_c
What safety risks are around a CNC router? Let's learn from other close calls

Copied from another thread:

The finger holding habit is a bad one which I think we are all guilty of so let me relay an experience I had some years ago.

While working on a Multicam I was cutting out large letters from 16mm MDF. The first test cut was at the back end of the machine and I wanted to pause the machine between cuts. Now for those unfamiliar with the Multicam, the pendant stores in a bracket at the home position and I was working at at X-max, Y-max. As it finished cutting the letter (which I had been holding down with my hands so that there would be no divot as it cuts loose) I moved my hands away from the cutter and started moving toward the pendant. the floor of the workshop at the time was painted with a fairly glossy floor paint and this combined with fine MDF dust caused me to slightly loose my footing, instinctivly I put my hands out to balance myself and ended up passing my left hand right through the cutter (still spinning at 18000 rpm with 1/2" router cutter). all I felt was the impact of the cutter hitting all my fingers one at a time, a bit like a drum roll. After uttering a suitable expletive, I placed my left hand under my right armpit and proceeded to shut the machine off. after allowing enough time for my heart to calm down to a mild panic I slowly tried to move each finger in turn while the hand was still buried in my armpit. Having satisfied myself that all digits still appeared to be attached and there were no bits on the floor I slowly brought my hand out to have a look. Thank goodness for TUV chip limiter design, all I had were relatively small cuts on both sides of all four fingers either side of the nail, not that that resulted in less blood. At that stage I was working alone in the workshop so with one hand wrapped in a towel to control the bleeding I shut the workshop down, switched everything off, set the alarm, locked up and drove myself home to attend to the wounds as we did not even have a first aid box then. No stitches were required and I was back at work on Monday with only band-aids on the fingers - VERY LUCKY!!!

Moral of the story: Use a stick to hold down parts if the cutter will come within 6" of your hand, make sure the floor is clean and clear of possible trip hazards, don't use glossy floor paint and most importantly, have a first aid box close at hand.
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  #2  
Old Fri 18 September 2009, 19:13
DMS
Just call me: Sharma #9 India
 
Rajasthan
India
OK I just noticed this thread and wants to share my experience.

Though I am always aware to keep my hands off rails.
I was cutting in the middle of board and cutting was about to finish so I started to grab spanner for tool change, it slipped and fell down on floor , instinctively I grabbed the rail with left hand and bent down to get spanner, gantry started homing and I felt my finger pinched between wheel and rail, immediately I wrenched free my finger. Reflexes saved my finger with miner bruises.

I decided to put guards on wheels, which is still pending.

I once also forgot rag on rail. Thanks Sean for proxy setup , Estop activated and gantry didn't derail.

Now I have a check list to check before cutting, it also includes to check rails for any objects.

Moral : Never ever touch the rail while gantry moving.

Last edited by DMS; Fri 18 September 2009 at 19:19..
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  #3  
Old Fri 18 September 2009, 19:22
smreish
Just call me: Sean - #5, 28, 58 and others
 
Orlando, Florida
United States of America
Sharma,
Don't thank me...Gerald put the provisions for the Proxies on the machine. I Just happened to the be the first "I think" to actually implement them in the controller.
Glad to see you have them tuned properly so they detected the slight deviation in height from the rail before a derail.
....I love it when machines behave properly.

Sean
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  #4  
Old Fri 18 September 2009, 19:54
DMS
Just call me: Sharma #9 India
 
Rajasthan
India
Yes you are right there, thanks to Gerald for that he has foreseen the necessity and put the provisions.
But you taught us what is required, how to connect and how to put them on MM

In fact the deviation was so slight that It took me some time to figure out why machine stopped until I saw the rag. LOL
Thank to all you guys.

Last edited by DMS; Fri 18 September 2009 at 19:57..
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  #5  
Old Fri 18 September 2009, 21:30
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
The possibility of pinching fingers on the x-rails has been mentioned too often and it is time that we changed the basic design to eliminate that problem. Something must be done to those gantry ends. That is food for a new thread - here.
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  #6  
Old Sat 19 September 2009, 04:35
Alan_c
Just call me: Alan (#11)
 
Grabouw (Western Cape)
South Africa
Send a message via Skype™ to Alan_c
Another area to watch out for is at the end of the gantry, I had a close call the other day when I reached down through the gantry to clear a piece of offcut that I could see was going to cause a problem, not paying propper attention, the Y-car changed direction and I managed to pull my arm out just in time before it got jammed between the Y-car and gantry end. I know it was a dumb move but only realised that after it happened.
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  #7  
Old Sun 20 September 2009, 11:11
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
Alan, I have looked at that risk and have come to the conclusion that it will cause a bruise at worst. Plus, that is the reason for having an e-stop at each of those "trapping" points.
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  #8  
Old Sun 02 October 2016, 05:43
lonestaral
Just call me: Al #114
 
Isarn
Thailand
Send a message via Skype™ to lonestaral
I thought I would share what happened today.
This job I have done many times before.
I was facing a wood strip to thickness.
145 x 32 mm.
0.75 mm depth of cut, 1500mm/ min feed, 42mm dia cutter.
Nothing aggressive.
2 dowels at the rear, cam clamp for side pressure.

There was a blur which lasted for 1/1000 second.
2 bangs.
Total time approx 1 second.
The blur was the work piece coming my way.
The 2 bangs were it hitting the wall behind me
and on its return trip past me hitting the the wall opposite.
I was extremely fortunate.
If contact had occurred the out come would have been serious to fatal.

Are you familiar with the term brown Adrenalin ?

I should do this job differently methinks.

Anyone got a drawing for a vice made of wood with replaceable strips in the jaws ?
Stay safe.
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  #9  
Old Sun 02 October 2016, 07:18
ger21
Just call me: Ger
 
Detroit, MI
United States of America
http://www.rockrivertools.com/
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  #10  
Old Fri 07 October 2016, 06:51
racedirector
Just call me: Bruce #122
 
New South Wales
Australia
Ordered one of the vices on the 4th and have heard nothing. Don't know what the issue is but at this stage wouldn't recommend them.
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  #11  
Old Fri 07 October 2016, 06:57
ger21
Just call me: Ger
 
Detroit, MI
United States of America
The plans from the link I posted? If so, there's a note to contact him if you don't receive the download link.
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  #12  
Old Fri 07 October 2016, 07:00
racedirector
Just call me: Bruce #122
 
New South Wales
Australia
Yup, done that twice including registering on the their forums.... still nada.
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  #13  
Old Fri 07 October 2016, 07:10
ger21
Just call me: Ger
 
Detroit, MI
United States of America
I've known him from a long time, so there's probably a reason. I think he may be near the hurricane's path, which might be the issue?
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  #14  
Old Fri 07 October 2016, 07:12
racedirector
Just call me: Bruce #122
 
New South Wales
Australia
Quote:
Originally Posted by ger21 View Post
I I think he may be near the hurricane's path, which might be the issue?
I tried to see where he was located on the site but couldn't. If he is near the hurricane I will retract my statement.
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  #15  
Old Fri 07 October 2016, 08:02
ger21
Just call me: Ger
 
Detroit, MI
United States of America
I sent him a PM through the Vectric forum.
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  #16  
Old Fri 07 October 2016, 08:06
racedirector
Just call me: Bruce #122
 
New South Wales
Australia
Thanks Gerry, appreciated
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  #17  
Old Fri 07 October 2016, 12:43
TReischl
Just call me: Ted
 
Rockford
United States of America
Hello Bruce,

Sorry for the delay. As much as I would like to blame it on the hurricane? Nah, I could swear I checked PayPal yesterday and there were no orders. I am thinking old age is grabbing a hold of me. Sheesh.

Appreciate your patience. I have sent the download link to you a few hours ago. Also, I will check the forum in case you do not see this reply.

Gerry? Thanks for the assist, I really do appreciate it.

Ted
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  #18  
Old Mon 10 October 2016, 02:18
racedirector
Just call me: Bruce #122
 
New South Wales
Australia
Forgot to answer this as well as your email.

All good Ted, happily I have the plans now and am well on the way to drawing the vice up in Fusion 360

Cheers
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