[dertsap]

while trying to quickly whip a new assembly together I had an aluminum part that was 4x4x.5 thick , so i threw it into the vise with stepped soft jaws and in the end end result there was to be a vise hold of about .075 , which I new was going to be somewhat flimsy , so anyhow while standing at the machine with my hand wrapped around the door handle , I leaned up against the door while watching the part and the controller , the sob part launched and labeled the door and my arm , lucky enough the lexan hasn't become brittle yet or I would have been pulling plastic and a 4 inch chunk of aluminum out of my arm . I've launched enough parts in my time but this one flew harder and faster than any of them
crappy pictures but it gets the point across , no blood or gore but its tender
live an learn

[Ed from NY]

Lesson learned: use 1/2" lexan

[Fastest1]

Glad you are alright. Funny how the human body would be more of a lubricant than an obstruction. Maybe a webcam in the enclosure and you can stand back!

[DSIF]

We machined similar parts years ago and had one launch across the shop at 6000 RPM. Luckily,no was killed. Afterward,installed 4 small washer/clamps on soft jaws for safety. Glad you are OK.
Dan

[Ken_Shea]

That's a real good post for all to take into consideration.

Very happy for you that you shut the door and/or the plastic did not give away.

[dertsap]

I knew I was treading on thin ice so at 10k i figured that running it at 50 ipm would have been slow enough for full engagement at a bit more than a 1/4" depth but sometimes i forget how aggressive the hi helix can be( i love em ) , I lightened the depth and ran another one , without leaning up against the door which is going to be a very difficult habit to break

[Ken_Shea]

Shouldn't be a difficult habit to break, pain is a great teacher

[dertsap]

LOL
yeh but I'm a bit thick sometimes , like the lab rat that gets zapped every time he bites the cheese

[Bwana Don]

We sent an aluminum bar through the side of the machining center. It went right through the sheet metal. Just underneath the controller. RPM was 15,000 feed was probably arpund 200 ipm. Operator forgot to tighten the vise up! Lucky no one was hurt.

[RICHARD ZASTROW]

How about some high speed balancing launches? I know of one flywheel explosion that exited through the roof and landed on I-94.

Also, a taper cone pulley went through the shielded roof of the balance area, ricocheted of the overhead crane and landed in the chip pan of a W&S 5A turret lathe.

In both cases no injuries except to underwear.LOL

Dick Z

[underthetire]

Man your lucky! We had a guy at work lean in to a hurco door the other day while the machine was running. Dam cheap machines, window fell right in and so did he. Just got wet thank god. I've seen double walled doors blown off lathes from part ejections, ceiling joists taken out, guys in comas, holes through castings, cross slides on big lathes ripped completely off, holders actually imbeded in the safety windows. Good reason to change the safety windows every five years as suggested by most manufactures.

[dertsap]

most machines that I've worked on in the past have had metal reinforcements around the windows which i think is the safest , that way nothing "should" fly out of the machine , I recall running parts in the past that were high precision and we could barely clamp down on them for the reaming (final) op , otherwise things would get whacked out , I had a 3/4" reamer pull the 50lb+ part to z zero (eye level) at about 750 rpm , by the time i hit estop and took a flying leap from the steps the part was thrown to the back of the machine , the flash picture that flashed thru my mind was the thing flying thru the unprotected glass

[christinandavid]

Used to grind die-sets on a large Lumsden grinder with a rotating mag-chuck and rotating stones. Many a dent in the steel guard from people touching on the job before turning the magnet on.

One guy was pinned down by the guard when it was knocked off its rails after an impact. The worst crime was probably when the same mistake was made with guard open (helps you see how close you are to touching on). Luckily the ejected slab missed everyone in its flight to the other side of the shop.

DP