Pegasus Research Consortium

General Category => General Discussion Area => Topic started by: PLAYSWITHMACHINES on January 09, 2013, 02:57:09 PM

Title: Engineering: how NOT to do it
Post by: PLAYSWITHMACHINES on January 09, 2013, 02:57:09 PM
I can't believe how dumb some so-called 'engineers' can be.
Here is a prime example, an overhead crane rail had broken loose inside the building, i had to go & investigate.
What i found was that the idiots had put the bolts in from underneath, with the result that the nuts had come loose due to vibration:

(http://www.thelivingmoon.com/inventors_group/images/ODD/bailey5s.JPG)

In one case, the bolts had fallen out completely, allowing the whole rail to come loose from the pillars;

(http://www.thelivingmoon.com/inventors_group/images/ODD/baileyb1s.JPG)

This is not only inviting disaster, its an irresponsible, unforgivable mistake.

The correct way to do it of course, is to put the bolts in from above, and secure them with 2 nuts, or use 'Nylock' nuts. This way, even if both nuts fall off the rail will still be connected to the pillar by the (loose) bolts:

(http://www.thelivingmoon.com/inventors_group/images/ODD/baileyb3s.JPG)

Next!
:D
Title: Re: Engineering: how NOT to do it
Post by: Sgt.Rocknroll on January 09, 2013, 03:25:28 PM
Yes, I have seen many stupid & potential criminal errors like these.
Title: Re: Engineering: how NOT to do it
Post by: Littleenki on January 09, 2013, 03:33:05 PM
basic knowledge one usually finds out the hard way...
Title: Re: Engineering: how NOT to do it
Post by: petrus4 on January 09, 2013, 03:54:14 PM
The entire world is built on what I call ponerogenic, or psychopathic engineering.  That is, things which are deliberately designed to be inferior, usually for political or economic purposes.  Occasionally it can be attributed to stupidity, arrogance, or laziness; but I tend to find that these three things are products of the general psychopathic environment.
Title: Re: Engineering: how NOT to do it
Post by: Somamech on January 09, 2013, 05:52:13 PM
Great Post PWM :)

I have learnt that its bloody stupid to do as you stated the monkeys did, which is something i have never thought of.  It totally makes sense to put the screws on the side where gravity and vibration may help them hold the structure together more so than those rather scary photo's :D

There is a Mega Structure type TV program running at the moment here in Oz and only last week i watched a section of some bridge being constructed in that region which makes NO sense in the desert  ;D

Now i feel like watching that episode again to see if they follow what you said  ;)
Title: Re: Engineering: how NOT to do it
Post by: Somamech on January 09, 2013, 06:02:51 PM
Quote from: petrus4 on January 09, 2013, 03:54:14 PM
The entire world is built on what I call ponerogenic, or psychopathic engineering.  That is, things which are deliberately designed to be inferior, usually for political or economic purposes.  Occasionally it can be attributed to stupidity, arrogance, or laziness; but I tend to find that these three things are products of the general psychopathic environment.

Oddly though for the most part Engineering does improve, designs get better and ways to improve end product do actually occur in some worlds on this planet!

I say that from being someone who has worked in protoyping for nearly 12 years, there are many bloopers in both engineering and manufacturing, but at the end of the day we are advancing in knowledge in a sorta whacked up world. 
Title: Re: Engineering: how NOT to do it
Post by: Ellirium113 on January 09, 2013, 07:15:36 PM
Was this a case of poor engineering OR was it an error made by the construction crew. One must call up the engineering prints for the rail and see what the engineer had called for. Personally I think even nylocks would be insufficient, perhaps the similar all metal lock nuts would be even better as they don't seem to work loose. Also would use hardened washers instead of mild steel.
Title: Re: Engineering: how NOT to do it
Post by: Sgt.Rocknroll on January 09, 2013, 10:44:20 PM
I guarantee that the plans did not have bolts upside down. This was minimum wage work and piss poor supervision!
Title: Re: Engineering: how NOT to do it
Post by: The Matrix Traveller on January 09, 2013, 11:24:12 PM
Bolting things together, screwing, welding and riveting, and the like is a monkey practice,
causing all sorts of problems.

Alien Tech. involves none of the above practices, instead they use "Interlocking" Structures.

One of the practices we need to learn about on Earth.

Wherever we have nuts and bolts, screws, rivets, and welding, etc. creates unevenly distributed
pressures, even if a "torque wrench" or other means are used, and you end up with , fatigue,
cracking and other undesirable Stress related phenomena within structures.
Title: Re: Engineering: how NOT to do it
Post by: PLAYSWITHMACHINES on January 10, 2013, 12:42:36 AM
Just an example, as i said.
Petrus, it's not psychopathic, it's just people not thinking about what they are doing

Sarge was right;
QuoteI guarantee that the plans did not have bolts upside down. This was minimum wage work and piss poor supervision!

Exactly!

QuoteWas this a case of poor engineering OR was it an error made by the construction crew
I think both. The engineer should have been on hand to supervise construction. The construction workers should have been better trained ;)

QuoteAlso would use hardened washers instead of mild steel.

What washers?
In the first pic you can see there weren't any, some of the bolt-heads on the more heavily loaded parts of the structure had been forced halfway through the hole.
These mild steel ones were all we had, that's why i doubled them up ;)

QuoteAlien Tech. involves none of the above practices, instead they use "Interlocking" Structures.

One of the practices we need to learn about on Earth.

Indeed ::)

Quote..creates unevenly distributed
pressures, even if a "torque wrench" or other means are used, and you end up with , fatigue,
cracking and other undesirable Stress related phenomena within structures.

True, but we can at least try to use the tech we have wisely :)

Thanks peeps, thought you'd like it.
Want another one?

Title: Re: Engineering: how NOT to do it
Post by: Somamech on January 10, 2013, 06:27:27 PM
I would love another one!   ;D

I start work in a few days and can post up an 'Oven' that has moisture in its glazing that is worth about half a mil to buy,  and oddly I have never seen moisture on any oven I have used to cook food with :D 



 

Title: Re: Engineering: how NOT to do it
Post by: thorfourwinds on January 10, 2013, 09:38:25 PM
Quote
Want another one?

(http://www.freesmileys.org/smileys/smiley-bounce016.gif) (http://www.freesmileys.org/smileys.php)YES(http://www.freesmileys.org/smileys/smiley-bounce016.gif) (http://www.freesmileys.org/smileys.php)
Title: Re: Engineering: how NOT to do it
Post by: PLAYSWITHMACHINES on January 11, 2013, 11:13:12 AM
OOO thanks Thor, i thought i was being a bore!
OK some more 'bloopers' on the way ;)

Somamech;
QuoteI start work in a few days and can post up an 'Oven' that has moisture in its glazing that is worth about half a mil to buy

Doesn't sound good to me. Parts with moisture in them, like glazing, will shrink and parts that are dry will expand.... ::)

I have seen industrial ovens expand by 3 inches or more  :o

Uploading more bloopers......
Title: Re: Engineering: how NOT to do it
Post by: PLAYSWITHMACHINES on January 11, 2013, 01:20:08 PM
You wanted more, so i've been digging in my archives..... 8)
OK to start off, a few 'bloopers' i filmed while doing my routine inspections:
This truck is not only overloaded;
(http://www.thelivingmoon.com/inventors_group/images/ODD/cort2.JPG)

...But it's also very out of balance.
I can't see how anyone in his right mind would attempt to drive it.....
(http://www.thelivingmoon.com/inventors_group/images/ODD/cort3.JPG)


However, the fun doesn't stop there, this fire escape has come loose from the wall.
This is because the upper part was joined to the wall, but the lower end was resting on the ground, which subsided.
DUH!
So i had to make a support, & fix it to the wall. Something that should have been done in the first place ::)
(http://www.thelivingmoon.com/inventors_group/images/ODD/trap2.JPG)


In the same factory, i found that this cabinet, which should be closed at all times, wasn't.
They could not close it because some moron had placed a relay that was sticking out too much..... ::)
This machine is a sandblaster, only it works with tiny steel balls.
The cabinet was full of them & had a massive short-circuit....

(http://www.thelivingmoon.com/inventors_group/images/ODD/cabinet.JPG)

Mind you, i soon figured out how good their electricians were when i found THIS;

(http://www.thelivingmoon.com/inventors_group/images/ODD/3fase2.JPG)
If these bare fuses had blown, it would have melted the whole box, and anyone standing near it!!

And now for the best pic, still from that same factory.
THIS is the power supply for the cental fire alarm system, the backup system, AND the glassfibre network!
Unplugging (or just tripping over the cable) will shut down the whole factory :)
(http://www.thelivingmoon.com/inventors_group/images/ODD/security.JPG)

More to come!
Title: How NOT to do it part 3
Post by: PLAYSWITHMACHINES on January 11, 2013, 04:12:33 PM
This time, we are at a cheese factory. :D

There's a problem with the vacuum flowpacker. :(
This is a machine that places the cheese in plastic bags, which are then vacuumed & sealed.
It does this in a long continuous running process (hence the word 'flow').

The problem was that 60% of the time, the vacuum wouldn't hold.
Something was damaging the packing, no-one could find out what, they had taken the whole machine apart.
Still they found nothing.
So i decided to look at the 'ribs' of the 'forming station' where the plastic (on a roll) is fed into the machine.
I found that someone had been using this (aluminium) part of the machine as an anvil, it was dented & serrated.
It was putting microscopic holes in the plastic before it went into the machine ::)
(http://www.thelivingmoon.com/inventors_group/images/ODD/edge.JPG)
Ground & polished, it worked perfectly....... :)


Next, there was a report of a metal detector not functioning, it had already rejected over a ton of cheese.
Having tested the detector (which was working fine) i decided to look further up the production line, and found THIS:
(http://www.thelivingmoon.com/inventors_group/images/ODD/splinters.JPG)
As you can see, a bearing has disintegrated, and left splinters, that slowly found their way onto the conveyor belt.
The machine had been 'inspected' and 'cleaned' 2 days before......Obviously not enough, they had to throw all that cheese away, because it DID have splinters in it!
:P

Then there was a robot that placed metal shelves on a plank.
Problem was, it kept mashing them all up...
(http://www.thelivingmoon.com/inventors_group/images/ODD/shelves.JPG)

This was because the servo-motors had no gradual acceleration or decelleration programmed in (which should have been) it was just 'bang-bang'.
I had already told the 'expert' in charge that this will mean excessive vibration, & that the robot was swaying so much, it couldn't pick up or put down shelves.

A few days later, that same 'expert' speeded up the machine, & whole sections of it broke off!
Oops! :-[


Then there was the lift for the palletiser.
This machine stacks boxes on a pallet, & then lifts the whole lot onto a conveyor.

It would move up most of the way, and then stop.
No-one could figure out why it was stopping.
I took a photo of this machine, can you see the problem?

(http://www.thelivingmoon.com/inventors_group/images/ODD/lift.JPG)




Yes, that's right, it's not level!
The right side is at least an inch lower than the left.
By no great coincidence, this is exactly the length of one of the chain-links ::)
The chains on the right have slipped over the sprocket, and the sensors for registering the height of the lift (on both the left AND right) were confused, so it stopped.
Duuuuuuh!
???
More to come...... ;)
Title: Re: How NOT to do it part 3
Post by: ArMaP on January 11, 2013, 09:00:35 PM
Quote from: PLAYSWITHMACHINES on January 11, 2013, 04:12:33 PM
The chains on the right have slipped over the sprocket, and the sensors for registering the height of the lift (on both the left AND right) were confused, so it stopped.
Well, at least in this case the machine was smarter than the "expert". :)
Title: Re: Engineering: how NOT to do it
Post by: PLAYSWITHMACHINES on January 11, 2013, 09:47:05 PM
That's right, it was well designed. It will stop rather than crash, unlike the expensive robot :)
The computer knew what was wrong, the humans didn't...

A bit of extra software could have displayed a message, for example, and then they would know where to look ::)
Title: Re: Engineering: how NOT to do it
Post by: The Matrix Traveller on January 12, 2013, 12:59:18 AM
Re my earlier post there is a couple of building companies investing in Interlocking Systems
to some degree. This includes Commercial properties as well.
Esp. after the Earthquake we had in Christchurch a couple of years ago.

One such Co. is LockWood.

Most of the construction of buildings involves Interlocking Components.

They do however use some tie rods in some cases .

Here is an example of their wall structures.

(http://www.lockwood.co.nz/images/WhyLockwood/superwall.jpg)
(sorry picture is gone, but here is the Homepage (http://www.lockwood.co.nz/WhyLockwood/EarthquakeResistance.aspx)---PWM)The tie rod seen in the above anchors the wall to the floor if a concrete pad is used
rather than a wooden floor.

In areas subject to high winds these tie rods are sometimes used with wooden floor constructions.

The silver wall is a aluminium clad exterior wall, where aluminium sheet is integrated with
an exterior wooden wall.

In other words the exterior wall planks are produced with the aluminium sheet attached.

But as you can see it is pretty much a "Interlocking Structure".

I am sure you will see more of this Tech. in the future.

Another Co. is Modulock.

No doubt there are others as well.
Title: Re: Engineering: how NOT to do it
Post by: PLAYSWITHMACHINES on January 12, 2013, 08:37:48 PM
Good point Matrix.
This also means faster more secure constuction. No more nails & bolts etc
Kind of like Ikea furniture ;)

Are you ready for part 4?
Title: How NOT to do it part 4
Post by: PLAYSWITHMACHINES on January 12, 2013, 08:39:17 PM
Now this machine is very large.
It's part of a transport system for large pipes.
The problem wass, the man who ordered it had no idea what he was doing, and the general construction company that built it had no idea what they were doing, either!

It was (according to the builders) specified to lift pipes weighing 80Kg.
The problem was, that was the lightest pipe in production, the heaviest was 280Kg!
Apart from that small blunder, it turned out that the damn thing couldn't even lift it's own weight!
The main moving part weighed over 4 tons!
In this picture, you can see the moving part is rubbing against the frame, not even so much as a washer between them:

(http://www.thelivingmoon.com/inventors_group/images/ODD/useless1.JPG)

Needless to say, the (too small) axles & bearings gave up within a month, this axle would have broken clean off, given time;

(http://www.thelivingmoon.com/inventors_group/images/ODD/useless2.JPG)

After countless repairs & retrofits, the machine was dumped the following year...
Cost? About 460,000 Euro's....... 8)



Elsewhere in this factory, another machine had broken down :(
This time, a lube pipe has broken off a year or 2 earlier;

(http://www.thelivingmoon.com/inventors_group/images/ODD/bearing.JPG)

The cage has rusted away & the rollers spilled out of the bearing.
And i had to SHOW them why the machine had stopped!
This could have been fixed for about 100 bucks, but no-one bothered.



Elsewhere in that same factory, a sludge removal conveyor has jammed.......

(http://www.thelivingmoon.com/inventors_group/images/ODD/ketting.JPG)

This is part of the filter for a gigantic industrial sanding machine.
What has happened is the operators just threw the bits of broken belts into the machine, rather than removing & disposing of them.
These bits have wrapped around the axle, broken the chain & some metal strips inside the machine.
Total repair time: 4 hours



On to another factory, this time it's to dismantle an extrusion press:

(http://www.thelivingmoon.com/inventors_group/images/ODD/container.JPG)

The problem is that a crack has developed in the main hydraulic cylinder, which is 4 feet diameter, and 10 feet long.
The crack happened here between the cylinder & the tie-rod hole:

(http://www.thelivingmoon.com/inventors_group/images/ODD/part.JPG)

Why?
Because the holes were too damn close to the cylinder, they weakened it!
Design fault ::)

After several very costly repairs, they threw it out....
Duuuuuuuuuuuuuuuuhhhh!



Next was a very interesting, yet insane job i had to do ;)

This was to install an infra-red camera on top of an oven, that could check for broken pins on the transport chain. This chain is about a mile long, so if it even LOOKS like it's going to break, the whole machine has to stop at once.
You don't want to unwrap half a mile of chain from all those (very hot) sprockets!

For some reason, they wanted a 'heat shield' behind the chain.I pointed out that the Infra-red heat coming from the oven would be an excellent backround source for the camera, which was only going to film a profile.
A diffuse backround source, such as that from the oven itself, was ideal.

(http://www.thelivingmoon.com/inventors_group/images/ODD/ir1.JPG)

To everybody's amazement (except mine LOL) the camera didn't film a thing... ::)

So they then decided (and this is the honest truth, i swear) to buy a special diffuse IR light source, and stick it on the heat shield!!
I duly did as they told me;
(http://www.thelivingmoon.com/inventors_group/images/ODD/ir2.JPG)

Stoopid, or what?


OK last but not least, i was asked to fit a label printer into a filing cabinet in such a way as it could still be used, without having to open up the cabinet.
It took me almost a day, even then we had to extend the monitor cable (yes the PC is in there as well) otherwise it would fall off the cabinet when you opened a drawer to change the ribbon etc.

(http://www.thelivingmoon.com/inventors_group/images/ODD/printer.JPG)

Mind you, it DOES look cool, but was probably the stupidest job i ever had to do ;)

There's more in the archives.....
PWM
Title: Re: Engineering: how NOT to do it
Post by: ArMaP on January 12, 2013, 09:13:32 PM
Quote from: PLAYSWITHMACHINES on January 12, 2013, 08:37:48 PM
Kind of like Ikea furniture ;)
I don't know if that's a good idea. ;D

Here in Portugal we use mostly concrete and bricks. :)
Title: Re: Engineering: how NOT to do it
Post by: ArMaP on January 12, 2013, 09:19:16 PM
I think you should write your repair-related memories, it has the potential to be a best-seller. :)
Title: Re: Engineering: how NOT to do it
Post by: 1Worldwatcher on January 12, 2013, 09:36:56 PM
I think the Extractor was the biggest 'Whoops!" of them all, it would have been quite easy with regular maintenance checks to see this was going too give way. I hope that the company that had designed the machinery divvied up the offset of design flaws back to the company that had purchased, it. I can think of a few ways of how they tried to mend the situation, but still scary to think of how much force was being applied to the machines mechanical parts while this machine was in use.

The Sledge separator also seems too be a maintenance issue from photos supplied PWM, I personally think that "YOU" PWM need too design a 'Maintenance Free" mechanical machine!!! LOL Fat chance, darn cars go left and right in my family, but , if by chance you do get this dilemma figured out PWM, let me know, be on your order list post haste!! :P

The file cabinet is self explanatory..HA ha ha ha... so what ever happened with their design concept with that filing cabinet? Big seller in 1r4N? LOL I suppose it was too alleviate filing and dumping orders for the Sexatary? Ha ha.

Being somewhat trained with in the MET areas, it was obvious that the designer of the Pipe lifter was out for re-reimbursement of the design and cost expenditures it was plainly visible the apparatuses design and functionality was limited, at best, for nothing more than a concept poorly designed and executed. All that money wasted for nothing more than paper weights and abstract art.
"We could have used those funds here with our our group ya Know!!" ;)

Either way, some great examples for Vol 4 of your thread explanations of "Engineering: how NOT to do it" for truth and understanding that the simplest over looked design flaw can lead to catastrophic failures too the point of absolute trashing of the machine and not too mention expenditure's that follow there with in when trying to recoup such mechanical devices.

Thanks PWM, great educational stuff for sure!! ;)

1WW
Title: Re: Engineering: how NOT to do it
Post by: PLAYSWITHMACHINES on January 12, 2013, 09:40:14 PM
You are far too kind :)

I do have plenty of anecdotes like this, in fact i'm working on part 5....

But i'm too lazy to actually write, it took me ages just to write this first chapter in the 'engineer's handbook'...
http://www.thelivingmoon.com/inventors_group/files/1,1.rtf (http://www.thelivingmoon.com/inventors_group/files/1,1.rtf)

http://www.thelivingmoon.com/inventors_group/files/1,2a.rtf (http://www.thelivingmoon.com/inventors_group/files/1,2a.rtf)
Title: Re: Engineering: how NOT to do it
Post by: 1Worldwatcher on January 12, 2013, 09:44:26 PM
Quote from: ArMaP on January 12, 2013, 09:19:16 PM
I think you should write your repair-related memories, it has the potential to be a best-seller. :)

Especially with in the Mechanical Engineering technology community, if this is what is happening with in so called "Experienced Designer" rendering's and research, these things could easily been rectified before manufacturing or mass production, When I was in AMT we had done many hours of Luminal Radial spectrometry with air craft frames, may cost a bit more, but sure yileds results for safety and structural issues.
Title: Re: Engineering: how NOT to do it
Post by: PLAYSWITHMACHINES on January 12, 2013, 09:47:48 PM
Thanks, but what really worries me is that these bloody 'experts' are also running things at nuke power plants, CERN etc.

I'm just glad i don't live there ::)
ETA: The one company that DID take my advice saved 45 grand in just one month.

Later on they fired me........
Title: Re: Engineering: how NOT to do it
Post by: 1Worldwatcher on January 12, 2013, 09:59:36 PM
Quote from: PLAYSWITHMACHINES on January 12, 2013, 09:47:48 PM
Thanks, but what really worries me is that these bloody 'experts' are also running things at nuke power plants, CERN etc.

And whats the worst that can happen with that can opener?  ::)
When they had the issues of the Helium tanks, thought that was going to  be the red flag for not turning it on..LOL If the Engineers there make such a obvious mistake as the engineers for the machinery of what you had provided, well, lets just say we might get some real scientific evidence for what happens when atoms collide with atmospheric pressures of our planet..Ha ha ha.   :o  Swiss Alp's might be viewed as the "Swiss Foothills" fun for the whole family to traverse..lol

QuoteI'm just glad i don't live there ::)

I always wondered why the Swiss Alps, heck, they were running smaller ones here in the USA that seemed to producing scale results. Now apparently not abandoned but not being fully operational. Forget the name of the facility that sports the bragging rights, but am sure you are aware of it's existence.

1WW
Title: Re: Engineering: how NOT to do it
Post by: Ellirium113 on January 13, 2013, 03:41:22 PM
Comming from working on heavy duty mobile underground equipment I can relate totally to re-engineering stuff that was designed by people who had never even been in the field. One trend I notice is that more manufacturers are integrating more plastic parts and sensors on equipment that works in places the sky rains boulders. Does not work so well a lot of times. We have to keep special towing slings on hand to recover equipment that breaks down or gets buried in the work areas. These have to be recovered by another remote control unit as NO ONE is allowed into the work area. It can be a bit tricky as all the brakes on all equipment are spring applied and must be released by hydraulic pressure to move the units. They have a special hook that has an actuator to dump accumulator pressure into the brake circuit to release the brakes when the tow cable tightens up.
Title: Re: Engineering: how NOT to do it
Post by: PLAYSWITHMACHINES on January 13, 2013, 06:17:17 PM
QuoteOne trend I notice is that more manufacturers are integrating more plastic parts and sensors on equipment that works in places the sky rains boulders.
Don't get me started on plastic >:(

Fine for Lego blocks, but it's mostly useless in the field. Even the ultra-hard PMMA (Lexan,Plexiglass) will go brittle when exposed to UV or heat, in other words, outdoors ::)

Not only falling rocks, but a lot of my problems with sensors was people standing on them ::)

My standard technique has always been to allow for this and house the sensor in a thick pipe welded to the frame, or a thick plate bolted to the frame. This allowed for easy adjustment of the sensor, and people can stand on it.
The drawback is that it may get knocked out of alignment, which will give problems, but it's a lot quicker, easier, and cheaper than to keep replacing sensors.

I have often replaced nylon bushes with bronze ones ;)

Quotean actuator to dump accumulator pressure into the brake circuit

I know these, they are either ON or OFF, must be a real pig to get them out....and i've had cases where the dump valve lever was rusted solid ::)

And i hate hydraulic oil,.
Hydraulics are very efficient & flexible, & it would be nice to see one with sunflower oil in it, something more environmentally (& human) freindly.

Anyone want to do some research on that?

Been digging in the archives, not much more on BAD engineering, but i've got a whole bunch of GOOD engineering examples from my past.
So i guess that will be 'part 2' of this thread :)

I might need a new forum, called 'Uncle Luke's Agony Column for Stressed Engineers' 8)
In the meantime, i'm very interested in hearing your stories, preferably with photo's?
LOL
Title: Re: Engineering: how NOT to do it
Post by: Back on January 13, 2013, 07:25:58 PM
I don't have pictures as we are not allowed to take pictures where I work. This happened a few months ago.
On our roof there is a 400hp motor that is part of our cooling system. There is a solid platform where a crane can set it down and a trolley set up to put it in place. they decided that they would not spend the money for a crane. They welded an extension on a fork truck and put 10 55 gallon drums on a counter weight. Stacked skids 8 high and had another lift put the motor on the skids. When they raised it to the roof 2 guys had to stand on the back of of the modified lift to keep it on the ground. The platform is about 5 ft from the roof edge. Then they hooked upped the trolley system and swung it to the platform.

It did work and no one got hurt. I still get cold chills thinking about it.

Bless
Back
Title: Re: Engineering: how NOT to do it
Post by: Ellirium113 on January 13, 2013, 07:26:28 PM
Quote from: PLAYSWITHMACHINES on January 13, 2013, 06:17:17 PM
Don't get me started on plastic >:(

Fine for Lego blocks, but it's mostly useless in the field. Even the ultra-hard PMMA (Lexan,Plexiglass) will go brittle when exposed to UV or heat, in other words, outdoors ::)

Not only falling rocks, but a lot of my problems with sensors was people standing on them ::)

My standard technique has always been to allow for this and house the sensor in a thick pipe welded to the frame, or a thick plate bolted to the frame. This allowed for easy adjustment of the sensor, and people can stand on it.
The drawback is that it may get knocked out of alignment, which will give problems, but it's a lot quicker, easier, and cheaper than to keep replacing sensors.

We have more of a problem where the pipe gets crushed from rock and you must dig it out and change the entire pipe, harness & sensors. We find some loom and keep the wiring as close to the main frame as possible so the upright supports deflect most of the damage or we route the wiring unde heavier components that can take a beating.


QuoteI have often replaced nylon bushes with bronze ones ;)

I know these, they are either ON or OFF, must be a real pig to get them out....and i've had cases where the dump valve lever was rusted solid ::)

In our environment we are finding the hydraulic ram attached to the system is corroded and seized solid. We usually just change out the works every so often.

QuoteAnd i hate hydraulic oil,.
Hydraulics are very efficient & flexible, & it would be nice to see one with sunflower oil in it, something more environmentally (& human) freindly.

Anyone want to do some research on that?

It all depends on your hydraulic setup...some pumps need higher detergents and anti-foaming capabilities. Some systems require nothing more than 10w30. There are many companies already working on these sort of oils though for example:

http://www.bio-lubcanada.com/en/our-products/59.html (http://www.bio-lubcanada.com/en/our-products/59.html)

QuoteBeen digging in the archives, not much more on BAD engineering, but i've got a whole bunch of GOOD engineering examples from my past.
So i guess that will be 'part 2' of this thread :)

I might need a new forum, called 'Uncle Luke's Agony Column for Stressed Engineers' 8)
In the meantime, i'm very interested in hearing your stories, preferably with photo's?
LOL

I don't have any good photos of equipment failures here...but next week I'll get you some doozies.  ;)
Title: Re: Engineering: how NOT to do it
Post by: Ellirium113 on January 13, 2013, 07:34:19 PM
Quote from: Back on January 13, 2013, 07:25:58 PM
I don't have pictures as we are not allowed to take pictures where I work. This happened a few months ago.

Yeah many companies are doing this they say because of "espionage" which is a half truth, there is a lot of blackmailing potential if pictures of safety infractions find their way to the inspectors without going through proper channels and reports etc.

QuoteOn our roof there is a 400hp motor that is part of our cooling system. There is a solid platform where a crane can set it down and a trolley set up to put it in place. they decided that they would not spend the money for a crane. They welded an extension on a fork truck and put 10 55 gallon drums on a counter weight. Stacked skids 8 high and had another lift put the motor on the skids. When they raised it to the roof 2 guys had to stand on the back of of the modified lift to keep it on the ground. The platform is about 5 ft from the roof edge. Then they hooked upped the trolley system and swung it to the platform.

It did work and no one got hurt. I still get cold chills thinking about it.

Bless
Back

:o That's a crazy one. It's all fun and games until someone loses an eye eh? ;D
Title: Re: Engineering: how NOT to do it
Post by: PLAYSWITHMACHINES on January 13, 2013, 07:58:23 PM
Back, i already got the chills when you talked about 'welding extensions'- this is not only very difficult to do properly, it's illegal. No wonder you can't take photo's ::)
Yes it got the job done, and if the weld is good then OK but it's still a suicide mission to load a forklift like that.

Typical bloody managers taking risks with our lives for a little more profit

Good for you Ellerium ;)
QuoteWe find some loom and keep the wiring as close to the main frame as possible

That, and place a quick-change plug somewhere near the sensor, AND a junction box here & there, so you only have to replace short lengths of cable ;)

QuoteWe usually just change out the works every so often.

Preventive maintenance eh?
At least they got that right :)

Nearly all the pics i showed are from big companies & are of course, illegal.
But what they are doing is illegal, too (or should be) so i say what the heck?

At least i'm not naming names ;)

Title: Re: Engineering: how NOT to do it
Post by: zorgon on January 13, 2013, 11:00:13 PM
Quote from: Back on January 13, 2013, 07:25:58 PM
When they raised it to the roof 2 guys had to stand on the back of of the modified lift to keep it on the ground.

LOL sounds like what we did all the time at conventions when the big machine displays came in

As to cameras at work... get yourself a necktie spy cam. Then you can get cool pics and no one is the wiser... like these at a DARPA convention revealing the 2004 deployed SBL (space based laser)  :D

(http://www.thelivingmoon.com/45jack_files/04images/Weapons/us_starwars_laser_07.jpg)

(http://www.thelivingmoon.com/45jack_files/04images/Weapons/laser01_13.jpg)

(http://www.thelivingmoon.com/45jack_files/04images/Weapons/us_starwars_laser_04.jpg)


Shhhh I know nothing.....

::)
Title: Re: Engineering: how NOT to do it
Post by: PLAYSWITHMACHINES on January 14, 2013, 05:06:49 PM
MMMM now that's a peice of kit i'd like to play with.
Smaller than i thought, too ::)

I see from the agenda that the whole project was scheduled to be fully operational in....2013

Oops  :-X