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Goofs & Blunders You Should Avoid.

lindse34

Active User
Active Member
When AC stick welding on an I beam in hot weather I had an arc strike down my forearm that was holding said I beam. My welding gloves and leathers had gotten pretty wet with sweat and lost insulating properties with sweat being conductive. What amazed me was the distance the arc jumped to my arm. My hood was up and I swear it cleared a 3 inch gap. When I popped my jacket off I could see 4 little burn marks where I assume the AC wave changed polarity. My saving grace was the current flowed out my hand and not through my torso and the swinging motion I was making continued and opened up the gap enough to stop the arc. Moral of that story either keep your welding gear dry or don't hold the workpiece (which in this case wasn't an option).
 

Wreck™Wreck

Active User
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see some guys on youtube doing this and don't understand the reason. can't read if it's moving so fast.
On a large lathe holding a large part it is difficult if not impossible to rotate the spindle by hand, this is especially true if you are indicating 60" from the spindle as there is nothing to hold onto on a round part, I gear the lathe slow and jog the spindle around.

As a disclaimer I have never watched a how-to machining video. I have no problem running the spindle at speed with an indicator on it, however I do a good deal of large parts where max spindle speed is less then 200 RPM,s.
 
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Groundhog

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I learned just 10 minutes ago that you probably shouldn't drain your air compressor into a pan just used to brake-clean parts. Especially when you open the valve too far and blast the contents onto your face, chest and arms. Oh well, the shower felt good and the safety glasses I had on felt even better!
 

kvt

Active User
Active Member
Not recent but a long time ago when I was young dumb and thought we were invincible, welding a small section on a car body, No gloves on, one hand and the car and grabbed the lead, Well just so happened that it had a bad spot on the handle, Did not get the rod close to the car, but the hand that I was using to steady myself on the car, had on my wedding ring, Boy did I jump and everything, Had fun pulled my finger out of the wedding ring as it was stuck to the car, blister from hell on my finger. It took me a long time before I would get close to the welder again, It belonged to someone else, and they had to get it fixed and prove that it was fixed before I would even get near it. Now wear gloves even on hot days, but from what Wreck Wreck said I may want to keep some dry spares around. By the way the wife told me not to wear my ring as long as I was working on things all the time. Did buy a new one but still have the old one just because.
Now I am wandering if that is not part of the reason my heart is not quite like it is supposed to be.
 

AlbertNakaji

Active Member
Active Member
I'm not convinced that this is either a goof or blunder. Seems like something quite unexpected and perhaps even unforeseeable. Good lesson, though.

When AC stick welding on an I beam in hot weather I had an arc strike down my forearm that was holding said I beam. My welding gloves and leathers had gotten pretty wet with sweat and lost insulating properties with sweat being conductive. What amazed me was the distance the arc jumped to my arm. My hood was up and I swear it cleared a 3 inch gap. When I popped my jacket off I could see 4 little burn marks where I assume the AC wave changed polarity. My saving grace was the current flowed out my hand and not through my torso and the swinging motion I was making continued and opened up the gap enough to stop the arc. Moral of that story either keep your welding gear dry or don't hold the workpiece (which in this case wasn't an option).
 

Wreck™Wreck

Active User
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Blunder last week, had to bore into a recess in an existing part for a repair, couldn't get the #1 tool into the recess to set the Z axis position (the #1 tool is what all other tool offsets are based on) could have put a gauge block in the recess against the shoulder and touched off the 1 tool on that to set Z. But no, it was a rush job and I am lazy so I touched off the boring bar an inch or more inside the end of the part and reset the bar Z offset to zero.

With predictable results from doing such a thing several hours later using the boring bar on another job I forgot about the 1"+ offset difference and rapided it to .100" from the end of the part, naturally it crashed at 100" inches per minute feed rate, broke the insert and rotated the tool post. Then had to spend an hour or more squaring the tool post, setting the work shift for tool 1 and resetting the offsets for 23 other tools, a real time saver. The good thing is that I never rapid a tool to the start position with the spindle running.
 
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British Steel

Active User
Active Member
Shop foreman handed me a 3/8-16 tap and told me to turn the shank down to less then the minor diameter as he was tapping holes deeper then the threaded portion. He is standing behind me waiting, I finish and grab it by the threads and pull it out of the chuck and say "it's hot" he grabs it and immediately flings it across the shop where it gets lost under a bench.
Sounds like the time my ex lost the keys for the disc lock[1] on her Yamaha - careful "shielding" the bike before making lots of sparks with the angle grinder, remains of the lock fall off after 5 minutes (those things are Hard and Tough - maraging steel!), she dives in with both hands and grabs the pieces, past my hands in heatproof leather gloves... She spent the next week smoking store-bought, couldn't roll cig's for the blisters :(

[1] a small shackle lock with a pin through the front brake disc, to prevent "roll-away" thefts
 

cs900

maker of chips
Active Member
some good lessons learned in this thread already, but I guess I'll add a few of mine as well.

Had just gotten done converting my PM45 mill to CNC and was excited to make some chips so I cut a part without the chip guard covering the Y axis ball screw (mistake #1). Being completely absent minded I though I'd clean the chips off the ballscrew before going onto the next tool. Stuck my fingers down there (mistake #2) to get the chips, and jogged the machine (mistake #3) to make the ballscrew rotate. Well the machine did exactly what I told it too, the ballscrew rotated and the saddle moved towards my finger. Almost sheared my finger off between the base casting and the saddle....rookie move...

Next one happened while replacing the suspension bushings in my buddies RX7. Tried pressing the bushing out of the rear a-arm, and the center of the bushing pressed out while leaving around 1/4" of rubber still on the a-arm. Being young and stupid I decided to take a sanding drum on a dremel and grind out the remaining rubber. Ok, worked like a charm....until a piece of molten rubber flew into my face and landed just under my eye. For those of you who have had molten rubber on you know it sticks to skin VERY well. Of course I wasn't wearing safety glasses. I ended up waiting for the rubber to cool and peeling it off, subsequently taking a few layers of skin with it.

But did I learn my lesson...of course not, I am invincible...Several years later I was cutting a bolt with one of those thin cutting wheels for the dremel (you can see where this is going) the wheel broke and sent a piece of itl flying right into my eye. There must be a god out there because at that very second I had blinked. The wheel hit my eye lid, and while it hurt like a bastard, it didn't cut/scratch/or otherwise effect my eye.

lessons learned:
1) don't be stupid!
2) patience pays off
3) wear safety glasses at all times in the shop, no matter how quick the job
4) wear safety glasses outside the shop too!





did i mention safety glasses? Use them!
 

kvt

Active User
Active Member
CS your eye one reminded me of one form abut 30 years or so ago, Remember the old big VHF antenna that you use to have on the roof.
Well got up there to do something, did not realize the pole was loose, it was windy I turned around just as the big gust of wind rotated the Antenna. One of the Aluminum rod ends right in the eye,
needless to say I had fun getting off the roof. Got in side tears running down my face, looked in the Mirror and could see the gash across my cornea. WEll, drove to the local clinic, they then chewed me out and put me in an ambulance to take me across town to the ER. WHere I got it again. Then when I got out had to find a way back across town to get my car. Which they did not want me to drive. What was bad my glasses are safety glasses, and did not have them on that day. I have been told that I am accident prone or an Accident magnet.
Expect the unexpected.
 

john.oliver35

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About a year ago I made a 1" arbor for my Rockwell 21-100 mill to use this blade with:
upload_2016-9-20_21-26-24.png
It has worked great - cut through 1.5" 4140 bar stock. A marvel of modern cheap carbide.

Turns out if you accidentally put the mill in reverse, even to touch off, you harvest a small pile of 28 teeth. Harvest time was tonight! Time to order another one!
 

kvt

Active User
Active Member
Yea the eye healed took a while and a lot of ointment. Tell you what it did give you a headache and a half. Now I seem to a bit cautious on things. My glasses are expensive as I want the safety style glass etc. case that was the second major thing with them. First was burn from welding flash. Was real bumb young kid and my father was welding outside between a white house and a shiny galvanized tin fence. I though it was fun to watch the bright lights on the fence. Till the next morning when I could not open my eyes. Of course he got in trouble for not watching me to ensure I stayed out of trouble.
 

scroggin

Swarf
Registered Member
In at the local galvanizers they have a photo on the wall from a trailer they tried to galvanize. After assurances that it was fully vented internaly they started dipping it in the molten zinc. One section wasnt vented. the buildup of pressure inside the box section caused it to explode sending shrapnel everywhere. There was a tidal wave in the zinc bath. They ended up with two ton of zinc on the floor and they couldnt move the crane to lift the trailer out because some of the shrapnel cut the electrical wires. It took two weeks to get operational again. Oh and dont ask them to galvanize something with internal venting. If they cant see the vent holes they aren't there!
 

george wilson

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Staff member
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My glasses are all polycarbonate. They do a good job of keeping flying hot chips out of my eyes. Only has happened just a few times,but a few hot chips have bounced off my glasses. But,once is enough if you aren't protected. Hot chips can stick to skin,too.
 

Aukai

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I have a quote "Experience is something you get right after you need it" New to machining, hope I don't have a bunch of new experiences that are painful.
 

kvt

Active User
Active Member
I thought your always did that to wash out the old oil, or at least that is what I told the wife.
but it is almost like remembering to put the drain plug back in the boat before you launch it. Have seen several boats have to be recovered because of that.
 

Heckle and Jeckle

Active Member
Active Member
Pay attention to what you are doing, do not clear grass from a running lawn mower. A ladder only has so many steps. Life is tuff for stupid people.

Last but not least use common sense and think for yourself.
 

george wilson

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Staff member
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My ex boss showed up at my shop one day,with the end on one finger missing at the first knuckle. Put his hand down to the grass outlet of his riding mower to clear something. At first he thought he'd hit a twig when he heard the "whack".
 

jpfabricator

Active User
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My ex boss showed up at my shop one day,with the end on one finger missing at the first knuckle. Put his hand down to the grass outlet of his riding mower to clear something. At first he thought he'd hit a twig when he heard the "whack".
I read this and my stomach did a backflip.[emoji20]

Sent from somwhere in east Texas by Jake!
 

4gsr

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Staff member
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My ex boss showed up at my shop one day,with the end on one finger missing at the first knuckle. Put his hand down to the grass outlet of his riding mower to clear something. At first he thought he'd hit a twig when he heard the "whack".
I don't know how many times dad drilled that in my head to turn off the mower before reaching down and touch!
 

jim18655

Active User
H-M Supporter-Premium
My ex boss showed up at my shop one day,with the end on one finger missing at the first knuckle. Put his hand down to the grass outlet of his riding mower to clear something. At first he thought he'd hit a twig when he heard the "whack".
I worked with a kid that did something similar with a gas powered hedge trimmer. He was trimming Christmas trees and a bee was bothering him so he started swatting at it. Guess where his finger went.
 

dpb

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I rebuilt a 1935 Delta 14" bandsaw. Was having trouble getting the blade to track properly, so I had the upper wheel guard off while I made adjustments. Decided to turn the saw on. Saw ran for about 2 seconds, then the blade broke at the weld. Broken blade lightly kissed my face as I attempted to teleport away. Upper wheel shot skyward, hit the shop roof still rotating at speed, shot sideways and crashed into my tool chest, 20' away. I had 4 tiny blood drops on my face, 1/4" apart, and a skinned knee from my get away.
Don't run tools without guards in place.