Expensive Experience

Broke a couple high speed pumps once. Didn't seem to be making head and flow, and we thought it was because the discharge line was not packed. Tried tinkering with the discharge valve to get it to run long enough to pack the line, until the seal blew. So started up the spare and did the same thing. Later we found out the pumps had been miswired, and were running backward. Also found that no one had filled the oil resevoir...

Live and learn... Always check rotation and oil level..

Yeh...there's that whole...

'that's funny that's what happened to the first one!'

thing .

Whoops, there goes another.... like you say.. without experience we'd still be there blowing 'em up....whoops and another....

I had a very similar experience years ago. I was replacing the thrust and journal bearings on a turbine driven pump (pump end) which has a hydro-pneumatic speed control system. I was so extremely proud of myself for getting the whole thing put back together without having any extra parts, that I forgot to readjust the governor (because it was drained of oil). Well, much to my surprise, I started the thing up, and it oversped and wiped the journal bearings I had just replaced. Of course, the overspeed limiter didn't work either because I had failed to recalibrate that as well. Much to my chagrine, I spent the next few days doing it over again. Lesson well learned.

"what is the most expensive/embarrassing thing you broke in the name of experience."

My second marriage.

It looked like this when I started......

and like this when I was done....

(not my photos but it's about right)

Glad you are alive!!!

While working in an electrical test laboratory I was the first one to use a brand new 3 phase 25A variac (the autotransformer type with the moving carbon rollers who's position was altered on the windings using a big rotating wheel). This thing was imported from Australia and weighed at least 10 times my own weight (taller too). I set the rotating handle on it to raise the rollers to give an output of 400V and connected my 10A load. 10 minutes later we had to put the variac out (it was on fire). Turns out that on close inspection the windings were not uniform and there was a bump in one of them (only one bump) which, when the roller was moved to a certain position, would allow only partial contact between the roller and the winding, creating an arc. 0-399V and 401V and above would have caused no problem. There is another story regarding a rather old and expensive moving coil power meter but it is not nearly as amusing.

Ahh memories, the only job I have had where I have got to yell the phrase "The switchboard is on fire, I am turning the power off". Seems like a lifetime ago.

Oh..that reminds me of my first job in a Hi-Fi and component shop in Soho London...A chap came in from 'Theatre Sound and Lighting' (TSL) and I sold him some big 50w wirewound resistors which I said he could use to dim some lights...

I was soooo wrong on sooo many levels . He bought 'em all back burned out...

My boss gave the guy his money back and suggested I refrain from offering gratuitous advice in future..(well I think that's what he said) Any how...he didn't make me pay for 'em..... After that, I started to learn about electronics, and eventually the Guy from TSL gave the tip that lead to my first real electronics job....so happy ending.

PS... big wirewound rheostats (pots' variables...whatever you want to call 'em) ... I mean.

They were ok at full resistance or zero resistance... they just burnt out in the middle...whoops!

A strand of Christmas tree lights that I "fixed", when I was 6.5 years old. I had seen my Dad use the soldering gun and electrical tape to fix cords before, so I gave it a whirl. Unfortunately I hadn't seen the part where he repaired 1 pair at a time. So I stripped the wires, twisted all 4 ends together, soldered and wrapped it. I was real proud of the job I did ..until I went to plug it into the socket to show him what I had done.

The blue arc as the plug blew out of the socket, lit up a look of terror on his face that I will never forget.

One of my recent regrets involves the oil drain plug on my car. Two gotchas got me. I was facing backward but failed to use spacial analysis of the bolt to determine proper rotation for loosening. The second one was I used my foot-long locking adjustable wrench instead of the short 14mm box-end one. The 1/4 turn the wrong way left me tinkering with it for a few months to try to stop the slow dripping thereafter.

Your sins are forgiven my son.... go in peace.

(No religious offence intended here...... _{[you'll all know if I actually intend religious offense]})

Del

Congrats!

You're one of the many members of Team Realtite!

My favorite inductee to the Team was the intern that used a tow-chain hooked between the bumper of his truck and the end of a 3-foot pipe wrench to "loosen" a 3" pipe union. His biggest mistake was coming back to the office and telling us about it. I still don't think he's lived that one down.

3-foot pipe wrench

Used a 3-foot pipe wrench to loosen a gland nut on the differential of a 1960 Rambler. Needed more leverage. 6 foot pipe did the trick all right. Snapped the handle right off. You should have seen the look on the face of the salesman at Sears.

I had to pull the main crank pully/harmonic balancer on my truck in order to get to the timing belt. I was not real sure if it was normal or reverse thread. I tried both ways for days, tried heat and impact wrenches, and every other way I could think of to get this thing loosened. The harmonic balacer was melted, the pully was torn up bad from trying to pull it, or hold it.

So I went to the dealer to get a new one, and asked how to get the old one off. They gave me a procedure that took 5 minutes to implement. I had about 24 hours, plus scraped knuckles, and about $50 worth of new pully invested in changing a $10 timing belt...

Right an update. Just a short while ago I discovered that someone had wired the earth of a high-end 3 phase 5.5kW variable speed drive, to one of the phase outputs. A continuity test and cursory inspection by yours truly showed nothing amiss. I am going to call this particular variable speed drive brand by a variant of its name, I am thinking either Bombfiglioli or Boomfiglioli (which is what it did when I powered it up).

Let this be a lesson to you all, always inspect every single connection even if it has been tested by others and looks fine and tests fine. Yes the job is urgent as well and yes the earth wire was the only wire I did not give a close visual inspection. Still it could have been much worse, some of the toys I get to play with have power and fault currents high enough to make them disappear in the event of a fault.

Badaboom......BIG Badaboom.

Dis they ever find the old dear who was standing on the road at the time????

A rocket, a helicopter and a cannon walked into a bar...

my first experience with packing reloadable rocket engines: exploded 15' off the launch pad

my first experience with building rc helicopters: tore itself up like a tazmanian devil

my not so first experience with a cannon (was a bit brave): there is such thing as too much gunpowder!

great fun was had by all... and the movies aren't bad either

The running shop joke it to "tighten it until you strip it, then back it off half a turn."

You know, I used to think that was funny.

-A-

Many of my blunders occurred before the age of 10. Constantly curious as to how things work ... lets see:

• There was the brand new and expensive telescope that fascinated me so much I had to take it apart. From that I learned that one should always devise some way to remember in what order things came apart.
• The antique medical thermometer that my grandparents had brought from the old country ... it's amazing how fast mercury rises! I wasn't even that close to the stove top yet!! From that I learned to apply variables very slowly until I know what is going to happen.
• Our very first color TV. First day home. I discovered color adjustment dials in the back!! Tom Jones was green for weeks until they had to call in the repair man. I learned to check settings first so that you know how to get back to where you started.

My parents didn't seem to appreciate all the scientific experience I was gaining at the time.

I have the same affliction.

I have an ability to destroy electronic devices soooo fast as a result of my constant "Huh, I wonder how that....." Which is always followed by "Nothing dear!"

I tightened a fuel filter bolt on a Spanish Dodge tractor unit, using a T-bar and socket (couldn't find my spanner?) and broke it (the bolt) the truck was off the road for a week waiting for a new bolt. I put the drain plug back into the sump of a Ford 360 Turbo so as not to lose it; it was never tightened and unscrewed, dropped the oil and seized the engine on road test.

yeh..that sump plug is a good un....

The 'I'll do it for safety' ..and then it makes it worse...doncha hate that?

Del

We do full on internal and external cleaning of our silos each year. A couple of years ago after we had finished up on the 250,000 lb flour silo I did my final inspection on the blowers and augers, signed off and said "fill it". A while later one of my mechanics came in and told me we had a low silo level indicator problem. The truck had pumped in 55,00lbs of flour but the panel was still showing low level.

When I went around back the 1st thing I focused on was the 30" manhole cover leaning up against the wall...

At least now I know I can get an extra 25,000 lbs or so in the equipment room under the silo...

Hi,

I once cut the yellow-green insulation to connect a new lamp aside the mirror in my bathroom.

Suddenly a shower of molten copper and steel droplets from a big spark burnt some points in my face and my hands (and shirt...) and made (fortunately) some deep craters in the glasses of my spectacles. The missing part of the blade of may swiss-arny-knife was 8mm in diameter.

The yellow-green was ok but the metallic frame of the mirror had full contact to 220V.

And my knife to both.

I did not feel the slightest electric shock, but it took a week to heal the skin lesions.

RHABE

Oh yeah. I once cut a pair of 110V residential feeds with some hardened steel cutters. I was in a small room and my backside put a hole through the sheet-rock. My pliers looked as though they had been attacked by a rabid robot beaver!

Okay I really did not want to go here, but.....

I worked as a machinist for many years so there are a couple of doozies.

The worst one? We were making a very unique part for a customer where a 110lb. block of aircraft aluminum was machined into a VERY expensive 40lb. precision part. After weeks of work the part was finished. It was stunning. The customer loves it except the engineer made a mistake and we were asked to open up a feature (I forget the exact dimensions ) from, say, .755" to .757". I was asked to perform this simple task on the companies great achievement. No problem. It took about 4 hours to set up and bore the feature on a manual mill. I bored the feature to within .0002" over a 4 - 5" length I (it was blind bore for the alignment rod that held the whole thing in place). Yup, I bored it a perfect diameter of .775" 'DOH! and 'DOH²

We actually were able to repair it; but holy crap what an ego crushing blow it was.

I tried so hard to block that out. Thanks Del del Gato!

cr3

Experience is linear linked to breaking things, we all know that.

Moped, 16 years of age, rebuild it, no oil, big oops.

Friends car, screen washer out, could not find ANY receptacle for it, oh here...found one, another big oops.

My car, idiot cut me up, I'll show you, acceleration deemed appropriate for battle-star galactica, next big oops.

My Yamaha, worn points, could not set them right, tried all day, got angry, sad oops.

At work, Customers DC drive, fault which I could not find, multi-meter in Amps mode, big bang and nasty smell, OOOPS. It turned out to be oil on the drive belt

At work, second hand machine, no manual, transformer without any legend plate, hooked up backwards, replaced fuses in main board as they kept blowing (duh), went to about 60Amp per phase until we started to think we should check something here. Bad day all together.

Only 2 days ago at work, dual axis microscope stage, connect to soak cycle computer.....nothing, lets try the next one, funny frazzling noise and that familiar smell again, 2 stepper motor controller drive chips are now firmly in orbit.

Why do we keep on trying the next one?

"Why do we keep on trying the next one?"

Well, D'OH! Because we already tried the previous one...

Two wrongs don't make a right, but three lefts do.

On one of my first transformer designs, I cleverly used a special grade of fish paper (slot insulation) and ordered a six month's supply, never realizing special grades were measured in square yards rather than the square inches of standard grades. My boss didn't fire me, but stacked all the boxes at the entrance to the shops with a sign explaining how stupid I was. It took me almost four years to use up that darn stuff, and thus take down the sign.

I designed and installed a new booster pump station control system. First time it was put to auto a program bug started closing the bypass valve before opening the suction valve to the pump. Water squirting out of the vertical pump's flange across the room right onto the electrical switchgear panels. Boss yelled that I had made the problem so I had to fix it, as he was running out the door. Glad I got it to manual and the valve open before it had fully closed. 26 miles of 24" diameter pipe with a high flow rate didn't break. "Only" 175 psi reached.

Replaced VFD on another pump station but didn't see note on station blueprint to take factory's input analog signal jumper out. On startup, immediately went to full speed. Many pressure relief valves in homes were replaced by water department service crews that day.

I forgot one.....well almost and deliberately at that.

I was asked in one of my apprentice period jobs, to turn down a load of copper printing rollers that had metal slugs in the end for journals. They were waste so all we had to do was to get the metal slugs out of each end and recycle the copper for Christmas money. Easy job so there I go.

Turned down the first couple no problem and by that time had established that the metal was in the copper only about 3/4". I therefor set the dials to the required cutting length and proceed with the auto cut off feature of our small lathe.

Take the copper roller out of the lathe after it had done what it needs to do and try to get the slug out. Won't shift so I put it in the vice and try to force it out, no can do brother.

In the end, instead of turning further, I decided to get a long scaffolding pole and knock the slug out of the end. Boy was this thing tough and by now I was engaged in a challenge I could not back out of, the slug had to die. I knocked and knocked and it moved a little so I thought, right one big one and job done.

Next thing I know is my hand flies right into the freshly turned copper knife edge of the tubing due to the weight of the scaffold pipe and blood everywhere. Funny numb feeling in my left hand and very, very wobbly knees.

Off to the hospital. I had a cut that went from my tip of the pinky, half through the nail, down the side of the pinky into the soft part of the ball of your hand all the way to the bone. The cut curled around both sides as I had my hand as a fist around the scaffold pole at the time of impact. Still makes me cringe and what an experience. Regained all the use of fingers so no permanent damage done, very lucky.

Just reading about it made my hands hurt - that must have hurt bad enuff to make you want to pee down BOTH legs... Ever figure out why that one was dodgy?

Yeah, colleague finished the job and said that that particular one, after he cleaned of all the blood, showed to have been in the copper tube over 1.5". We thought it must have been a left over slug on the end of the bar or done by an apprentice. They are soldered in the copper so it was firmly stuck to put it mildly.

Funny isn't it, job done by an apprentice only to mess up some other apprentices hand 20 years later.

In the early days I was a CNC Mill programmer. I'd been working on this giant steel blade for a Norwegian logging company, on a MAZAK multi axis machining center. Nearly two full days of milling ... and almost finished. One last adjustment needed to take a little off the top. So I punched in the code for the cutter to travel .002 inches in the negative Z axis, then pushed the start button.

KA-CHUNK!!!!!!!!!!!!

The sound reverberated throughout the whole shop. It shook the floor and shook the earth. It seems I missed a decimal point and my multi-bit cutter proceeded to attempt to travel 2 inches ... through solid steel.

Destroyed the very expensive blade I was working on, destroyed the mill bit holder, knocked the entire mill table out of alignment ... the cost was considerable.

Who'da thunk ... just a measly decimal point could cause that kind of damage! Just one little dot

Awww crap. Now you've reminded me of a couple of others. I will preserve my shreds of dignity by simply saying "been there dun that" Oh yeah.

About a hundred years ago I worked in a machine shop that specialized (or so it seemed) in really weird stuff that apparently nobody else could (or would) touch. One of the items I worked on was just the opposite of yours; tiny little parts that looked like 1/10-scale thumbtacks and were the one moving part in a type of hearing aid. The flat top had to have a groove milled across it - I fail to recall the dimensions, but the distance from the edge was +/-0.0001 inch. I used up nearly a production run of the little stinkers trying to get the jig set. Every time I'd turn down the setscrew to lock it in place, it would throw the measurement of by 0.00005 inch or more, and I'd ruin a part, then another one getting it re-set. I actually got maybe a third of them right. Some solace - no-one else in the shop could do any better...

Reminds me too.

I was working one part of my apprentice period in an injection moulding company. I was in the tool shop where we made our own holders, mother moulds and moulds.

I rode a Honda at the time which needed a bit of stiffening at the front end so I asked the foreman if I could come and do some milling work on Saturday in my own time and use a slug of aluminium. Yeah no problem at all, factory is always open so come when you like.

On the said day the big boss also happened to be in but I proceded as if I knew what I was doing and I was supposed to be there, he didn't know who I was and neither did he seem to care. He stood just behind me and was talking shop to the foreman. I was milling on this piece of aluminium, manual in those days, and suddenly I must have tweeked the knee up instead of down and a destinct <_ping> was ever so slightly audible from my part of the workshop.

I looked guilty as hell but thought I covered myself well and just proceded with a new cutter. The bossman walked of and the foreman came to me and said, I know you fucked up, you looked like you know you fucked up, but fortunately for both of us the bossman is not techinical enough to know anything and I am not going to tell him either so next time, be more careful.

Sure as hell a lesson tought with pretty well dosed humility. Those lessons you remember the best, bless his soul.

I was working on a hydraulic unit [vickers 20gpm]. This unit had been down for 10+hrs, so mgt. was in a proper frenzy by the time I came on shift. Did the usual checks.

1 oil in the tank

2 pump running the proper direction

3 soliniods on the various control valves engaging

Making pressure just not much.

Change the relief valve, several times, but we only had used 1's. Still no pressure?

I removed the pipe for the relief & put a gauge directly on the output of the pump.

Hit the run button

Crack followed by a river of oil

split the pump in 1/2 & blew the top off the gauge!

Told ya the relief was bad!

This was in a bakery the flour dust in the oil wore down the spool in the relief, this particular system cycled 20 times per minute, so certain parts would just wear out after several million cycles.

Mgt. still didn't believe, until the the hydralic tech[outside service] told them the same thing.

The line ended up being down for 72hrs, while parts were air shipped in [ouch].