Confessions 25

[D Scullion]

Many interesting links shared detailing other peoples screw ups. Anybody on here willing to admit to their own?

Not trying to entrap anybody, don't admit to anything you could still get prosecuted for. Just want to hear a few funny stories.

I'll start: My first job in a small engineering firm with very little senior experience, almost every day was a near miss:

- Prototype 24 ton dump trailer, my first folly with hydraulics, on placement from uni. I designed the small hydraulic rams that open and closed a gull wing style back door to operate on the same circuit as the very large rams that lift the 24 ton laden body, without any flow controls. On first operation the back door closed so hard and fast it damaged the solid steel door.

- Ordered a laser cut sheet steel kit for a first production batch of a new product. Didn't realise AutoCAD was set so that all files were scaled 10:1. Received a delivery of miniatures.

- Made a tolerance error on the pivot of a large arm that moved a prototype piece of machinery into operating position. It seized up so tight only the hydraulic ram on the arm could turn it, couldn't even get grease into it. Prototype was on a tight deadline for a demonstration in front of a large group of customers which we had to go ahead with. Started to move the arm and the screeching from the pivot was mortifying. needless to say we waited until everyone had left after the demo before folding it back in again.

 

[waross]

About 10 years ago when I moved to Alberta I did drive a little faster than 100. But faced with the amount of driving and the distances to jobsites, I worried that if I didn't slow down I may start raking up speeding tickets and eventually loose my license. I find that there are quite a few drivers that feel like me and we cruise at about 105 to 107 KPH.
We let you and the rest of the 120 KPH guys go on past.
My confession #2 is about feet and inches.
I may have told this one before. I was working in a remote mining camp and the office trailer was moved.
I had to move the antenna for the VHF radio telephone.
I checked the length of a folded dipole for our frequency band and measured and cut a new antenna. As I was raising the new antenna one of the other workers walked by and dropped the comment;
"Did you use that tape measure? Did you know that there is about 17 feet missing from the middle?"
Good joke. I'd heard that one before. Three guys peeking around the corner as the victim of the joke looked for the "missing" inches on a tape measure.
Just the same, I did a check.
Sure enough, I found where the tape measure had been nicely taped back together with a big piece missing.
Down came the antenna to be remeasured and re-cut. (With new wire. Cutting the original antenna longer didn't work out. grin)

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[Sparweb]

Having learned to map in feet and tenths

Wow, I have never even SEEN a tape in feet & tenths. Where can I get one? I could create some serious havoc by leaving them around in the wrong places. He he. I would never do that.

My confession:
Customer wanted to install an instrument inside an aircraft wing. Access into the wing through the existing access holes did not allow the long cylindrical instrument into the wing so we needed a larger hole. Took measurements of wing and instrument and existing hole to figure out how big the new hole had to be to fit the instrument inside. Returned home (4-hour flight away) to office and started to draw, creating CAD model of the wing and its new access hole. Discovered I already had a CAD model of the instrument. Didn't confirm instrument measurements in the existing CAD model. Drawings done, customer cut the wing open, fit up the new access panel, and it was time to test-fit the instrument. Doesn't go in. After much to-and-fro on the phone, I eventually figured out the CAD model of the instrument was 2 inches too short.

No one believes the theory except the one who developed it. Everyone believes the experiment except the one who ran it.
STF

 

[Ingenuity]

Wow, I have never even SEEN a tape in feet & tenths. Where can I get one?

Get one here: Link

 

[EdStainless]

Had a 100' steel tape that was metric on one side and ft-1/10s on the other
The tenths of a foot (and tenths of those) are easy to mess up, 100 to a foot looks a lot like 1/8" marks (96 to the foot).

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

 

[oldrunner]

All surveyors chains (tapes) are in feet and tenths. The surveyor rods are also in feet and tenths. I've used chains that are two hundred feet long. Hard to pull straight when two people are trying to get an accurate measurement.

It's a sin to break a chain.

 

[MintJulep]

Surveys in feet and tenths of feet.

Fence company or landscaping company workers do not understand what is a tenth of a foot.

They see 50.7' on a survey and think that means 50 feet, 7 inches.

A whopping 1.4 inch difference.

Or are those "survey feet" on the survey? Because those are different from "international" feet, which aren't used anywhere except the US.

 

[Phil1934]

Liberia and Myanmar also use Imperial measure

 

[oldrunner]

Since 1959, "American" feet and "international" feet have been the same. Curious note that I was a party chief in Liberia and was checking a French firms work on the elevation of a remote already constructed bridge. (1958) We used feet and tenths. It was to bad that the already constructed bridge was four feet too low.

 

[Agent666]

I used to work with a guy who lived in an imperial world in a metric country (at the time we had been metric for something like 35 years). He was this old guy who never grasped metric.

For example I used to tell him to cut a piece of pipe 5678mm long, and I'd have to hold his finger on this mark on the retractable steel tape and he would coil up the steel tape in his hands and trot off to the location of the pipe and unravel the tape and attempt to measure and cut the peice of pipe without stuffing up his finger position marking the correct length. About 50% of the time after all that it was the wrong length, sometimes out by meters if he lost his spot. I quickly learned to only trust him with measurements under about 1500mm as he didn't have to coil up the tape.


This whole metric and imperial discussion reminds me of the NASA mission to Mars that plowed into the surface upon entering the martian atmosphere, afterwards it was revealed apparently that half the team was working in metric and the other imperial units of measure and neither knew it, but they had been happily trading numbers.

 

[byrdj]

this aint an admission of error on my part, but since the discussion has turned to measurement units;
I once spent an afternoon trying to locate base plate positions for equipment skids on my first trip to Korea using a Chinese tape (1.3 US"=1 Cun") I think my assign engineer was having fun seeing the factory guy confussed

 

[dik]

A mixup in metric fuel, we had the Gimli Glider... a Boeing 767 run out of fuel at about 40,000' and the pilot 'glided' it to land at an abandoned airfield north of Winnipeg... all 60 or so passengers survived.

Dik

 

[Sparweb]

I still can't get over feet in tenths.
Do you call these units "toes"?

No one believes the theory except the one who developed it. Everyone believes the experiment except the one who ran it.
STF

 

[waross]

A humorous twist to the Gimli Glider.
I read a report that a crew of mechanics were sent out to Gimli to assess the damage of the plane, and their van ran out of gas on the highway.
Of the two pilots, one had extensive glider experience and the other had flown out of Gimli when it was in use by the Air Force.
There was another report that Boeing set up the scenario in a simulator and there were a number of simulated crashes before one of their test pilots was able to simulate a safe landing.
Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[oldrunner]

SparWeb:

You should understand that most civil engineering curriculums require a year of surveying - and all of the US measurements are in feet and tenths of a foot. The California civil engineering professional license test requires an additional a separate section on
surveying which would also require the use of feet and tenths of a foot. It's also easier to add tenths than it is eights. But a young surveyor almost immediately learns how to approximate the tenths of a foot into the nearest 1/8".

 

[dik]

... and the pilot was found 'at fault'.

 

[MacGyverS2000]

I made a PCB a few years back for a rush project (well, EVERY project was a rush project on that job). Our process was engineer #1 creates a part model, engineer #2 verifies it as correct, then everyone can use it. The part in question was an Ethernet jack, so it was hung off the end of the board an appropriate amount to fit through a faceplate, then the usual EMI-reducing components were stuffed in next to it. Board was sent out for manufacture.

The good news is the functionality tested great. The bad news is you had to insert the Ethernet cable into the jack from INSIDE the case. Yep, whomever made the model had rotated it 180 degrees. But to get even that to work, you had to desolder the jack and pitch it upwards about 15 degrees so the cable would clear the EMI components (but at least it was testable)

The really bad news? I was engineer #2 $25k down the drain.

Dan - Owner

http://www.Hi-TecDesigns.com

 

[fel3]

See my last entry in this thread:

https://www.eng-tips.com/viewthread.cfm?qid=439755

(I'm confessing there for someone else )

==========
"Is it the only lesson of history that mankind is unteachable?"
--Winston S. Churchill

 

[Spartan5]

It is super easy to discern the values on a grade rod graduated in tenths and hundredths of a foot. I can't imagine making multiple readings in fractions of an inch and then computing results quickly. Running clean level loops over a few thousand feet was pretty nerve wracking as it was.

 

[HamburgerHelper]

I suppose another thing that I learned is that doing 6 things right is much better than trying to do 10 things but only doing 9 of those right. Slow and methodical is much better and faster than quick and loose. With quick and loose, you'll have to deal with the problems at the end of the project, waste time with redoing work, and people don't feel like they can trust you. Doing work or saying things that you are not 100% sure of is gambling and eventually it bites you.

------------------------------------------------------------------------------------------
If you can't explain it to a six year old, you don't understand it yourself.

 

[berkshire]

When I worked back in the UK.. The company I worked for had a foundry with a pattern making department. A source of great amusement was to watch a victim enter that department to measure something without bringing his own rule. He would inevitably be handed an expansion rule. Needless to say the resulting part would always be slightly too big. requiring rework by the victim when he figured out what happened.
B.E.

You are judged not by what you know, but by what you can do.