Workshop Mistakes (True Confessions)

Just had one in the shed this morning. Wiring a tail-light onto a motorbike I used a male and female bullet connector, those horrible crimp on ones from the auto parts store. I hate the look of those squashed plastic connectors so decided to put a bit of heat shrink over the plastic sleeve on the female fitting to hide it. Hit it with the heat gun and promptly shrunk the heat shrink tube AND the plastic surrounding the metal fitting inside. So bad that the male fitting would not go in, even after a bit of "rework" with a screwdriver to open the plastic up a bit. Cut the whole mess off and did it again, without heat shrink.

So I won't do that again and must order some more proper solder-on fittings or the crimp on ones that use the special pliers and then you slip the sleeve on afterwards.

Tidy versus untidy? In theory, I vote tidy, but in practice I let disorder prevail. Something about my memory makes it quicker for me to pick up parts and tools from a clutter, rather than 'waste time' keeping everything in it's proper place. Now I'm older, the system doesn't work half as well, probably because my short-term memory is iffy.

I started the thread with a cast-iron tale of woe, which is still causing trouble. Demoralised, I returned to fix the job and found the workshop in total disorder. Items in the work area included a sink plunger, broken umbrella, a scattering of used emery paper, random twist drills, the spilled contents of a collapsed scrap-box and much, much more. And everything was and is covered in smeary black graphite. Two hours cleaning and tidying have barely made a dent in it.

I think I either need an Apprentice, who I can bully into keeping the place tidy, or one of those terrifying foremen of yesteryear, a vicious b*st*d who eats lazy sods for breakfast.

Oh, and early yesterday morning, I was out in a snowfall trying to clean off orange dust stuck to my double-glazing. And there's a big orange circle in the middle of my patio too. I knew angle-grinding cast-iron was messy, and still underestimated it. Good job I'm already divorced...

Dave

Aye, good job. Or you soon would be, by the sound of it!

Dave, when grinding cast iron the orange dust has a propensity to bond with the glass of double glazing if it’s is still hot when it hits the glass, don’t ask how I know, I am still married, only just after peppering the windows of the conservatory. Dave W

Oh yes, reminds me of another.....

Removing the old galvanised steel water pipework in the bathroom of my first house, before re-plumbing the whole place.

Often with pipes in a fixed installation - especially near a corner - you cannot get a hacksaw in there, (or any other sort of pipe cutter), and even if you can, hand sawing pipe with a hacksaw is very difficult because the teeth jam on the pipe walls. So I used my angle grinder........(This was years before somebody invented the multitool).

I cut through the pipes no bother and proceeded to instal new copper water and central heating pipe throughout the house, aided by my new pipe bender tool. Fantastic, except that there seemed to be some grey/black mould on the bathroom tiles, which would not wipe off. Oh dear, it was tiny blobs of zinc, (I assume), that had heated to red-hot during the angle grinding, and then fused into the glaze of the bathroom tiles.

OK, I was inexperienced then, but about 5 years later, I did almost exactly the same thing in the bathroom of the next house - this time, the zinc blobs landed on and fused all over the base of the white basin stand. I had to go and buy and instal another brand new porcelain basin stand !

PS, yes, don't jack cars on "domestic" tarmac without some sort of plate under the jack or axle stand, and always use axle stands, never just a jack.

I'm still maintaining that I've no idea what those little black bits stuck to the kitchen window are. Using a Stanley knife blade as a scraper helps, but nothing gets rid of it totally

Acid; e.g. sulphuric or hydrochloric, should dissolve the metal but not touch the glass - most acids are stored in glass bottles.

However, the logistics of applying strong acid - without it dripping onto and damaging the plastic or metal window frame, or yourself - would be challenging........

I think double glazed glass panels can be removed from the frame by gently prising off the internal plastic beads.

Note: I have not personally attempted either suggestion, so proceed at your own risk !

Edited By John Doe 2 on 15/03/2023 10:40:17

Been there, done that, tried to blame atmospheric pollution - that didn't wash! Put self in dog-house.

My biggest mistakes are two-fold and mutually supportive:

- No proper drawings, or even fair sketches first.

- A tendency to over-think and so over-complicate the problem hence the resulting metalwork;

both leading to a lot of rework later.

.

I can vouch for swarf loving to colonise its surroundings far and wide. It would explain the orangey-brown rash on the PVC still of my back door.

. Measure once. So I do. Measure twice. So I do. Cut once... Oh Dear! Start again....

.

Even the experienced (and supposedly skilled) professionals can be caught...

Among the stock at my club's workshop many years ago was a large hexagon of thin steel sheet, donated by a member who'd scrounged it from his works scrap-bin. In fact it was scrap only because when he remarked to the workshop manager that he could not cut the requisite number of hexagons from the supplied sheet, he was firmly told to look at the drawing again.... of an octagon.

In one of my employments the company, making its own products to its own design, proudly bought a CNC Milling-machine with among work lined up for it, a complex part carved out of a big slab of aluminium-alloy plate. All would have been well had someone first ascertained the part-width + cutter allowance against the machine's wee bit smaller travel specifications in the catalogue. The drawing-office re-designed the part a slightly bigger wee bit smaller.

'

I do though recall a retired gentleman, properly time-served and educated, formerly a senior engineering-manager in the nuclear-power industry. He had come back to work part-time, now for a specialist, bespoke electronics manufacturer, where his role was making small but often intricate metal components with a lot of hand-work in them. One day he told me of sometimes in his managerial days having to stand next to very skilled machinists working on large, extremely high-grade components; to give them moral support and read the dials and micrometers with them. It was not that the part was too difficult for them, but they knew it was functionally critical and worth many thousands of pounds, and were too frightened to be all alone in making its finishing cuts.

I often wished in my later days that I had transferred from making 'things' into Quality control, no chance of scrapping £££'s worth of parts, no real time pressure and so much higher paid, I was truly amazed how much money some of them were paid for shuffling paper. I'm sure some will disagree

Tony

Totally agree with you Tony, most places I have worked the inspection departments were made up of failed machinists, those that were too slow or made too much scrap, and they strutted around in their pure white coats telling the “ handle turners” how it should be done, and getting paid a fortune for shuffling a few bits of paper. A case of Those who can, do. Those who can’t, inspect. I shall now collect tin hat and go hide in shelter.

You don't want to be in QC, you can still make a mistake and pass off something that's wrong causing problems down the line, or fail something that's right, wasting money. QA is the place to be, truly an exercise in taking what's basically a good idea and strangling it in paperwork

I think there are some huge assumptions going on here, not least that left to their own devices production always do a perfect job. So let’s split things up a little. China makes a lot of stuff commissioned from the west otherwise known as offshoring. They can make rubbish or they can produce the highest quality you want. All down to the quality control department of the commissioners.
Do you still say they are an irrelevance.?

regards Martin

QC is really no different to any other department, when it works well it’s brilliant it can also be a waste of space.

H and S is the same, we love our HS dept. They save us from no end of work.

Edited By Martin Kyte on 15/03/2023 14:58:48

Probaly my epic failure was very much self inflicted.

having made and fitted a 80T gear, in nplace of the standardn 40T, for the input tom the Nortonn box, had mto remebr to mentally adjust the chart settings.

WANted to cut a 1.5 mm pitchn thread for ER collets.

So need to llok at the settings for a 3 mm pitch.

Became obsessed with the 3, and ste B-3. The nut would not screw on.

After a lot of further work, reality struck B-3 wad NOT the correct setting, so had cut a thread that was out by about 16%.

Once the cirrect gearbox setting had been made, the clamp nut screwed on quite happily.

Fortunately had decided to cut thenthread as first operation, so minimal loss of work.

If all fails, read the instructions!

Howardd

Skipping over the instructions, or not bothering to read them at all, might be the most common human mistake of all!

Admittedly instructions often feel like a perverse intelligence test, but admitting defeat far too quickly and then trusting to luck seems a universal fault!

Faced with the irksome job of reading a 300 page manual, I apparently believe I'm clever enough to pick up a full understanding by randomly pressing buttons until something sensible happens...

Dave

Noticed the little wire brush that cleared the teeth on the bandsaw had stopped turning. Reached out to give it an encouraging flick...

Fortunately many things these days are processor controlled and set up tends to be menu driven often displayed on small screens and are usually quite self explanatory. I find that once setting new stuff up becomes a frequent task you tend to acquire a kind of generic familiarity with the way things are designed as far as user interfaces are concerned. Icons tend to be standardised such as the little cog wheel for settings or parameters. Having a reasonable knowledge of how stuff operates helps, as you realise what the device needs to know in order to function as you wish. I am not saying I never need to read the manual but happily I do find that generally I know what I’m looking for when I open it and I can say I never read manuals from cover to cover. I find it enlightening to see my wife try and set some of her gadgets up, she really does not know where to start, why should she, so ropes me in.

There are obviously some things that defy logic in setting up but generally things are more and more user friendly.

Think of it this way, if you were faced with a lathe you had never used before I suspect you could drive it after a short while of familiarisation as you know what you want it to do and that you expect there to be levers to engage feeds, reverse motors, turn on coolant etc.

Half of the battle is confidence and knowing what to expect which is what I have and my wife doesn’t.

But do read the manual if it doesn’t become obvious.

regards Martin

Many years ago, it would have been in the mid 70’s, I was working on my car, a large Cortina 2000 estate, I had it jacked up to carry out a repair on the rear near side wheel area, can’t remember what repair it was, I was in a dream not focussed on what I was doing, I undid one bolt and the consequence of which was that the rear axle was disconnected and it then swung down to the ground, unfortunately for me my hand was directly underneath it. The edge of the brake drum came down heavily across the back of my hand, after I lifted it off I could see that there was serious damage to my hand, there was a large cut right across the back of my hand in which I could see bones, non broken fortunately, and tendons and blood vessels. I got taken to hospital by a friend, nearest A&E was about 45 miles away, and x-rays showed no serious issues so it was stitched up, healed relatively quickly but I still have the scar to remind me what a lack of concentration could result in.

Another instance of lack of concentration occurred when I was in the machine shop at Tech College, we had a long row of lathes against one wall and I was doing some machining with one and had just inserted my workpiece in the chuck and tightened it up, started the lathe and simultaneously there was a loud clang from the wall at the end of the machine shop, yes I had left the chuck key in place and it had been propelled with some velocity across the machine shop. The instructor let go with some very choice language and really laid into me, so much so that even now I remember how humiliated I was every time I tighten a chuck on my lathe. It was very fortunate that my flying chuck key missed hitting anyone otherwise the consequences would have been serious, they say we learn by the mistakes we make, I certainly learned from that one. Dave W

My long running clock project includes a 59 1/2 tooth wheel.
cut with CNC showing that CNC executes errors in a more efficient way than by hand.

You cannot have or cut a 59 and1/2 tooth wheel.

You can however have and cut a 59 and 1/2 gap wheel.

🥴