How things are designed these days

[Michael G]

I try not to stick up for engineers if I can help it, but in the digital battery thread there was a comment made implying a poor design by the engineer involved. Pete went part way in explaining some of this but there are several issues that contribute to what we the consumer see, and some of them you may not have even realised. (This is based on my years of working in various companies designing and manufacturing products - it should be roughly right but I'm not claiming 100% accuracy)

Back say 100 years ago the chances were that engineering companies were run by engineers (generally pretty good ones) and so while products may not have been exciting they were of a decent quality and did what they were meant to do. Financial returns were modest but (usually) did not fluctuate wildly. In the '60's "professional" managers started appearing and the emphasis changed to maximising return on investment - ie chasing profits. In addition, specifying product went from being done typically by engineers to something likely to have been done by marketing types

In no particular order, some of the issues contributing to "modern" product design -

Products are not necessarily released when they are ready but to coincide with an event (trade show etc) - that means that sometimes a less than optimal design is used because there is no time left
Engineers are these days close to the last link in the design chain. Marketing specify what they think the market wants; Industrial Design design the outside and then engineering is left to sort out the details (ie the electronic functional bits). I've worked in a company where the release deadline was set at the start of the project then marketing rejected the styling that ID devised twice (meaning they had to start over), so instead of having 9 months to finish the design, engineering had around 4 as the release date did not change.
Related to timing issues, there is a great reluctance to "start again". Trying to explain to non-technical managers that you were going up a dead end and needed to scrap 12 month's work and start again is not done. The face saving solution is to patch things up as you go, hoping that miracles are possible. As most engineering design is conservative in nature to deal the with uncertainties in reality you get by but with reduced design margins.
In an effort to save expensive resources, the design of equipment may not even be done by an engineer. Especially with product that is a copy of something existing in the market (that is, something without radical new technology in it), it may be given to someone who is just told "make one of these". In the case of cheap digital calipers, a draftsperson could have been given a Mitutoyo pair and told to reverse engineer the circuit board. However, one of the things about developing new product properly is learning the tricks involved - so the Mitutoyo engineers may know that the tolerance on a particular component is critical but a copier won't. Result is less than optimal performance.One company making appliances discovered that the optimal control curve is almost but not quite a straight line...
Related to above, companies go to some length to protect their intellectual property (IP), so people reverse engineering may not always know what it is they are copying. They may guess (and be very close) but will not always be 100% certain. I've seen numbers ground off chips, boards painted with epoxy paint, non-standard materials used, memory chips configured to be wiped if tampered with and so on.
Cost savings are another thing too. In order to save money some places will annually do a cost down on products - so that the self lubricating plastic used by the engineer to stop hinge noise will be replaced by the purchasing guy with a cheaper non lubricating plastic to save money. I had this once - we saved 3 times the cost of original cost saving by eliminating the extra warranty service calls. What happens if the caliper manufacturer found a cheaper supplier of components? (Of course you rarely get anything for nothing, so the chance is that reliability or other properties are worse)
Last of all, not all engineers are equal. I've met engineers who are very good at what they do and can be trusted to design a really good product and others who leave you wondering how they got through high school. It will depend on how tight a rein they are kept on too. Most engineers like designing things as best they can and will try to include the features they would expect to see (good battery life for example) but one place I worked at, including things in the product that were not in the spec was a sackable offence. If marketing don't care about battery life then the rest of the organisation is not allowed to either.


Michael

[simonl]

That's an interesting read Michael, and an insight into the world of engineering/design, from an "outsiders" prospective. it's in vast contrast (as you would naturally expect) to a design brief I go through when I wish to design something for myself. Admittedly there is no marketing department (although sometimes I do need to include a marketing department to "sell" the idea to the SWWMBO) and the cost is not necessarily the largest consideration. Also because I'm the project manager (is that the correct term?) I get to decide what features and level of quality are important to me! :D This is obviously a much more simplistic approach to what happens in industry!

Simon

[nearnexus]

I don't agree with your hypothesis Michael.

Bad design is nothing new, it's always been around us,

The automotive industry is a prime example - endless stupidity in badly designed, poorly placed, totally unsuited, almost impossible to work on design.

Bean counters have always played their part, otherwise engineers would run riot and there would be no profit.

In your list you left out "designed with end user in mind" - how often is stuff workable, but could be nicer to use, simpler, better placed.

This goes down to bar codes on packets placed under fold overs, munchie packets that are designed to be opened by left handed people (eg. Arnotts Shapes boxes) etc.

So this is nothing new as far as I see it.

Cheers

Rob

[Grahame Collins]

Geez Michael don't get me started!

Thinking back, when I have purchased tools/ machines in the past , it has often been an impulse buy. The new breed of tool purveyors understand me very well and accordingly gear many of the inputs into the tool that fire up my desire for ownership at the time of first contact. A lot of these tools that try to look like the more expensive tools are beginning to show up in the so called box stores,ie, Masters & Bunnings.

Packaging, form and appearance are king. Function, quality and longevity take a back seat in many cheaper end tools - not all I will grant you.

Indeed many tools are disposable, timber cutting handsaws with heat induction hardened teeth are but one example.

I almost fell for the impulse buy yet again in Masters the other day.

On display was a a pair of long jaw RH tin snips- Wiss brand but quite similar in mechanism and form to German Eyrt brand BUT on closer inspection the jaw bodies were not solid cast or drop forged but formed from a much thinner section of bar stock. The plastic hand grips were thinner and would fall to bits or slide off before much time had elapsed. The shiny bits were flash chromed would not be shiny for very long in the atmosphere in my local area.

The impulse suppressed, I put the item back on the shelf and went home hunted out the straight Eyrt snips and comparisons made reinforced my reservations about the cheaper copy.

Vice grips -the brand - are yet another example of the cheapening of the original product.Compare an old set against a Erwin model and see the rivets and pins are smaller and the springs Thinner in section, the chrome plating is thinner- One might as buy a no name brand.I do have a few no name v grips but they are modified for specfic purposes.

Grahame

[Michael G]

I don't agree with your hypothesis Michael.

Bad design is nothing new, it's always been around us,

The automotive industry is a prime example - endless stupidity in badly designed, poorly placed, totally unsuited, almost impossible to work on design.



Agree - bad design is nothing new and I would not say that engineers always get it right, but those examples from the car industry actually reinforce the point - the marketing guys want the new model for (example) the Sydney motor show in 2017. The stylists develop designs for how the car is going to look. The bean counters get involved with the marketing guys and the specification ends up saying that feature X can cost $6.55. That's it. The design engineer can spend up to $6.55 per car on a feature that must be ready for the motor show. He/she is locked into a cost and a date. Bad luck if it can't be done in the time frame, bad luck if you can't get all the function that you want. That feature must be on the car, because marketing only works if there is a point of differentiation.
The feature itself may have only been a gleam in the stylist's eye - that is, "we need a cup holder and it must be located around here somewhere" How it packs away and deploys is left to the engineer, which is why Phil's daughter's cup holder was such a B to fix. He/she was constrained by cost and real estate.
Even the functional stuff is no different. The size of the car and hence the engine bay is dictated by marketing/ industrial design. Bad luck if there is not enough room to work on it comfortably. Apparently the engineers working on the Veron were told that the shape of the car was fixed. Anything they needed to do had to fit within that shape. No exceptions (normally there is a little wriggle room).

(Another) true story. I had a designer tell me that they wanted a feature in an appliance that functions just like the one in brand X. "But that one does not have that function" I said. "Oh" said designer. "We want one just like the one in brand X, but has a ... function!". It's easy when you can tell others to sort out the problems...

The "designed with the end user in mind" idea is one that good designers try to bear in mind, but when you have washing machines styled by 23yo men fresh out of uni who still live at home (and their mothers do the washing), what hope have you got?

Michael

[simonl]

I think I have worked out how the design thingy goes within the car industry!

At Nissan things seem pretty straight forward to me. Only takes two blokes to design a car! :D
https://www.youtube.com/watch?v=fmmBfT6HYmM

Simon

[wheelinround]

Michael great input as well as others who see the other side of things.

In the auto industry there is a book of times taken to do jobs its done up by bean counters who have never been on the floor or waiting in line to use machines or tools. While those who do use them might have to alter settings not once but many times to produce what they need to. This is worse when your building custom designed or you have to work around others stuff ups.

Manufacturing in the bus and coach industry as I did as well as the engineering top shop making pressed items using punch machines etc. Anything can still go wrong.

I remember our Tech teacher who made each of us measure an item the same item write down exactly what we saw, Then my eyes were 20/20 other with coke bottle glasses. Yes some had the same reading others either side.

having worked as a mechanic seeing machined bell housing line up holes out by 2 to 3 mm as well as input shafts out into flywheels by 1.5 which throughout my gear box badly.

Cheap crap not my landcrusier :no:

[RayG]

Design, can be a complicated process. Initially it consists of determining what the constraints are and what functionality is desired. As basic as it must do A,B,C and D.. and it has to fit in this much space, and cost less than $X

No black magic really, but stuff I've done is mostly industrial control, where the constraints are bomb proof, bullet proof.. and ultra reliable.. belts braces watchdogs and layers of fail over.. cost is usually not high on the list.

Consumer and automotive electronics are designed to quite different constraints to, say, Military, Avionics, Medical or Industrial.. you might have equipment with similar functionality, but totally different design constraints and design emphasis.
By emphasis, to illustrate, what's the difference between a school bus and a ferrari? both have 4 wheels, a motor, fuel-tank, headlights etc... it's just a question of emphasis. :) (and constraints)

I've seen plenty of consumer products where you would think the design is really bad, because they used component X to save 0.01c instead where common sense says they should have used component Y, but, is that really bad design? The designer was given a brief to do something with cost constraints, and came up with a novel solution that saved some fractions of a cent... you could argue that it's actually good design, because he got the job done within the constraints.

I can recall a meeting once where there was full-on shouting match between the accountants and the engineers over the addition on a single red led, that cost just a few cents....

Back to power consumption, nowadays most battery powered electronics the power consumption is determined more by the software than the hardware, deciding when to slow the cpu clock, and when to sleep, how to wake etc... all software design decisions.. In the case of Mits vs the Chinese, I haven't dissassembled either, but I'm willing to bet that the Mitutoyo would be a fully custom proprietry ic.

Ray

[cba_melbourne]

In an effort to save expensive resources, the design of equipment may not even be done by an engineer. Especially with product that is a copy of something existing in the market (that is, something without radical new technology in it), it may be given to someone who is just told "make one of these". In the case of cheap digital calipers, a draftsperson could have been given a Mitutoyo pair and told to reverse engineer the circuit board. However, one of the things about developing new product properly is learning the tricks involved - so the Mitutoyo engineers may know that the tolerance on a particular component is critical but a copier won't. Result is less than optimal performance.One company making appliances discovered that the optimal control curve is almost but not quite a straight line...

Michael

Hi Michael,

in the particular case of the "Chinese Caliper" I can shed some light.

A small Swiss family metrology business by the name of Sylvac had designed and patented in 1972 (by Hans-Ulrich Meyer) "capacitive displacement measuring instrument".

Looking for ways to reduce cost, the inexperienced Sylvac found a Chinese company that was able to produce caliper parts in China. Big mistake, the Chinese company gave the confidential know how to other Chinese factories. And thus the "Chinese Caliper" that we all know was born. It is an unauthorized clone of the first generation Sylvac capacitive caliper. Sylvac is a small family owned business and does not have the money to fight patent infringment in China. The Swiss learned their lesson, and later caliper generations are again manufactured in Switzerland and the know-how stays there too. This is the Sylvac website: Sylvac - Swiss manufacturer of precision measuring instruments (http://www.sylvac.ch/)
Nowdays Sylvac calipers use their own "absolute" inductive sensing patent. Probably because the capacitive systems is incompatible with liquids. In the US, Sylvac calipers are sold by Fowler.

[nearnexus]

If I would say one thing, it is that design should at least be getting BETTER than in earlier days, given the CAD and design computing software power now available.

I remember when I was in IT (mainframes) GM ran the design for the 1972 HQ Holden through it's new generation software in about mid 80's and found that the car had about twice as much steel in some/many areas as necessary.

Probably why they were so robust in real world crashes.

But getting back to early design, the poms pulled some real shockers with their vehicle designs pre 70's, and I believe most British tanks in WW2 were so badly designed they broke down and saw stuff all action.

LOL it's a good subject.

Rob

[wheelinround]

If bean counters can make engineers cut corners and do it cheap :rolleyes:........what hope have we got buying the stuff exy or cheap.

[PDW]

If you guys think that the design and design constraints on stuff you can touch is bad, you'd really, really hate to know what goes on in *software* development..... I've walked away from some software projects, big ones, run by really big firms, because I just *knew* it was a total screwup early on. I away 2 years of my life on one notable failure and the lesson sunk in. Never again. Of course not everyone has the luxury of quitting, but it's very satisfying compared with the alternative. Mind you one of these days someone is going to get a 99 year licence suspension because I found a logic path to an event I was told "could never happen and therefore didn't need to be considered". Of course it's likely that someone has subsequently removed that little clause in a complex CASE statement - but I wouldn't bet money on it...... PDW

[nearnexus]

If you guys think that the design and design constraints on stuff you can touch is bad, you'd really, really hate to know what goes on in *software* development..PDW

Yes, we have glaring examples of this in Toyotas that speed up to flat out in the USA, VW Golf that shut down at any old time, jet aircraft where thrust is reduced on stall warnings, the list goes on.

Rob

[Gammaboy]

having worked as a mechanic seeing machined bell housing line up holes out by 2 to 3 mm


Castlemaine Rod shop bellhousing?

[Pete F]

... jet aircraft where thrust is reduced on stall warnings, the list goes on.

Rob

Can you provide specific examples of this?

[RayG]

Yes, we have glaring examples of this in Toyotas that speed up to flat out in the USA, VW Golf that shut down at any old time, jet aircraft where thrust is reduced on stall warnings, the list goes on.

Rob

Hi Rob,

I'd regard these as bugs or faults. Could even be component or assembly failures. The design issues are failure of the design to detect and fail safely, so in the case of the VW Golf, the design should have allowed for detecting that something was wrong and reverting to manual control rather than shutting down... someone, somewhere, decided that shutting down was the safe option. Unfortunately that's not the case when you are doing 100 kph on the freeway with a B double on the rear bumper.

Ray

[Michael G]

Having worked as a mechanic seeing machined bell housing line up holes out by 2 to 3 mm as well as input shafts out into flywheels by 1.5 which throughout my gear box badly.


Yes, we have glaring examples of this in Toyotas that speed up to flat out in the USA, VW Golf that shut down at any old time, jet aircraft where thrust is reduced on stall warnings, the list goes on.

You've got to be really careful here guys - There are some issues that are genuine design issues where someone hasn't thought something through, but a lot of this sort of stuff is not a design issue as such but a failure of process. In the modern automotive industry in particular there are all sorts of processes in place to limit the possibility of something going wrong, so for some of this it may not be the original design engineer at fault but that the checks and balances are not there or incorrectly applied.

Normally if an automatic system goes wrong the safer alternative is to shut things down but some things you can't and then it is a matter of recognising that and altering the response. Trouble is, as things get more and more electronic finding a way to deal with all the fault possibilities get harder too. I'm not sure that there is a B-double sensor on the market yet though. Ray is right, in that the electronic's response was not appropriate for the situation but then again it could have been appropriate for all the fault situations that were reviewed.

As Pete will tell you though, a lot of pilot refresher training is to deal with things that are unlikely to go wrong but if they do will spoil your day. I don't know all the details of the failures mentioned, but sometimes incidents are compounded by the people involved doing the wrong thing. In this day and age people seem to want risk free existences without acknowledging that there is risk in everything and that electronics can only do so much in compensating for inappropriate judgement or behavior. When doing Failure Mode Effect Analysis (a common automotive risk mitigation tool) we were always told to analyse the possible not the improbable. Software failure would have been dealt with. Software failure + B double right up your bum? Unlikely to have been covered.

Anyway, a long handed way of saying that not everything that goes wrong is a design issue and it is not solely the original designer that is always at fault.

Michael

[Skew ChiDAMN!!]

There's also the cases where an implement can be designed exceptionally well... but what makes it out of the assembly plant bears little resemblance.

One of my long departed uncles used to design hifi valve radios/amplifiers. As a young kid we had a cheap(ish) valve radio in the kitchen and one day Mum told me he'd designed the innards. Years later, I asked him why he never mentioned it (he was the type to mention all his past achievements at every family meeting, so his omission always seemed to me to be a bit odd, considering it was in plain view of everybody... :rolleyes:) and his reply went something like "I designed a good radio. The penny-pinchers pulled parts out of it until it stopped working, then put the last one back. That's what that thing is. It's not mine."

I suspect things haven't changed that much...

[wheelinround]

Castlemaine Rod shop bellhousing?


Toyota Crown was first I came across then Landcrusier there were others.

[Ueee]

Can you provide specific examples of this?

He read it on the internet. It had to be true right?

[nearnexus]

He read it on the internet. It had to be true right?

I was referring to the crash into the forest (in France ?) of the (A380?) during a test flight where the software reduced power when the plane should have been climbing. Was widely publicised as a software fault. Everyone was killed. Some videos around showing it occur.

[Pete F]

I was referring to the crash into the forest (in France ?) of the (A380?) during a test flight where the software reduced power when the plane should have been climbing. Was widely publicised as a software fault. Everyone was killed. Some videos around showing it occur.

It's difficult to even determine what you may be referring to, that post being so devoid of any fact, but I presume you're talking about this incident?

https://www.youtube.com/watch?v=Y1FKAIrb0fQ

That being the case, it was an A320 and not an A380, the latter has in fact not had a hull loss (touch wood) to date. It was not a test flight, it was a fly-by at an airshow. The aircraft operated precisely as it should have operated and there was no "software fault" nor did the software "reduce power". Jet engines don't accelerate from low thrust settings very quickly, which is part of the reason we use very high drag on approach to ensure the engines are "spooled up" ready to go-around if needed. Not everyone was killed, indeed everyone survived the accident. Of all the passengers on board, only 3 were killed, and then only because they either couldn't or didn't evacuate the aircraft after it came to rest. It was however in France, yes. :rolleyes:


He read it on the internet. It had to be true right?

Indeed! ... or not even :((

I'm not trying to pick on anyone here, so before being too offended try to understand the point, that is firstly just because somebody says something on the net doesn't make it true, but in relation to this topic, this is exactly the type of instance where BS just gets perpetuated as fact. Assuming that was the incident being referred to, the engineers copped a lot flack after that incident for designing a "faulty" aircraft. It put Airbus' fly-by-wire project back years as a result (indeed there's still significant scepticism by many, despite it being used by Boeing now also). Once the investigation was complete, it transpired that the aircraft had performed precisely as it was intended to.

But hey, carry on.

[wheelinround]

You've got to be really careful here guys - There are some issues that are genuine design issues where someone hasn't thought something through, but a lot of this sort of stuff is not a design issue as such but a failure of process. In the modern automotive industry in particular there are all sorts of processes in place to limit the possibility of something going wrong, so for some of this it may not be the original design engineer at fault but that the checks and balances are not there or incorrectly applied.

Normally if an automatic system goes wrong the safer alternative is to shut things down but some things you can't and then it is a matter of recognising that and altering the response. Trouble is, as things get more and more electronic finding a way to deal with all the fault possibilities get harder too. I'm not sure that there is a B-double sensor on the market yet though. Ray is right, in that the electronic's response was not appropriate for the situation but then again it could have been appropriate for all the fault situations that were reviewed.

As Pete will tell you though, a lot of pilot refresher training is to deal with things that are unlikely to go wrong but if they do will spoil your day. I don't know all the details of the failures mentioned, but sometimes incidents are compounded by the people involved doing the wrong thing. In this day and age people seem to want risk free existences without acknowledging that there is risk in everything and that electronics can only do so much in compensating for inappropriate judgement or behavior. When doing Failure Mode Effect Analysis (a common automotive risk mitigation tool) we were always told to analyse the possible not the improbable. Software failure would have been dealt with. Software failure + B double right up your bum? Unlikely to have been covered.

Anyway, a long handed way of saying that not everything that goes wrong is a design issue and it is not solely the original designer that is always at fault.

Michael

Michael Having worked from chasis level through to putting number plates on of Car's, Trucks, Buses & Coaches, Ambulance bodies.
Initial pre-delivery checks at dealerships and repairs, restorations.
Knowing design teams no longer work together but on each individual bit then try marry them up to fit parts coming from around the world

.. I have seen some incredible B&^% up. Electrical wires worn through, burnt, inaccessible nuts, bolts, screws which should be easy for need of general service requirement. Oil filters, fuel filters, break lines, handles, key locks. Holdens HQ if you had 3 or more keys attached to ignition key an turned the steering wheel the wrong way the keys dropped out and locked the steering.:o

The time Nissan put a car/4x4 on the road with blessing of many gov depts even the NRMA gave it a bonzza write up.........it had no reversing lights.:rolleyes:

I understand why people want/demand risk free design those who are designing and engineering and running the show go through Uni for years, they get paid what mere mortals make in a life time or take a life time to make. They are supposed to be the cream of the crop who have proved they can out do others.

I'll mention the government website on re-called goods which are dangerous, can and have killed.

Its simple to blame the fellows on the front line doing the assembly its how ever sad we see little of Journeymen these days fellows who have worked their way through from the ground up in all industry. These fellows can see more and avoid more disasters because they have been hands on.

Edited to add. I still have respect for good engineers and other proffesionals who take their job and do it well. For those who must stop and pass it on becuase they don't know the next faze or use the excuse "Its Not My Job" sorry at all levels from the ground up please let someone who can do the whole job take over.

[A Duke]

Hi,
Every one seems to have forgotten, or is skating around the old chestnut

"Designed by a comity" :oo:

Regards

[Grahame Collins]

Who here has not not worked on that vehicle that was fitted with an engine where the engine oil filter,oil drain or some other part is almost inaccessible.

I know its a problem where the same engine or gear box ,or diff is used in a number of models. The computer yells (edit-should be tells) the engineer or designer that there is clearance.

What the computer does not know is what clearance humans need to use said space ,but are not equipped with multiple elbow joints to fit into impossible spaces.

Yep! I'll agree with Wheelingaround and further add that the engineer./designer should be made to work on the prototype changing out those consumable parts just to understand what the end user has to deal with.

Grahame

[Pete F]

Grahame I can assure you that computers don't "yell" at anyone, they're a tool to accomplish a task. I can also assure you, that any mechanical engineer worth his/her salt working on a design such as you've used as an example would know full well just how much clearance is needed by a human hand.

I think what some people missed, is the emphasis that engineering is all about compromises. That's not to say there isn't bad engineering, there's certainly no shortage of that, but often it's a case where there hasn't been enough (or any, with some copy attempts) engineering input into the final product. Just because you found a oil filter difficult to access doesn't mean that it's "bad" engineering. Maybe one of the design constraints was the volume and specific dimensions of the engine bay made it difficult to impossible to locate it anywhere else.

[A Duke]

I think the problem here is the engineer designs an engine to be an engine, but the body designer is given a 3D silhouette of what has to fit in the engine bay that he designs. By the time the fopar comes to light all the tooling has been set up and deadlines are past. If the problem gets far enough up the management chain and it's a firm that cares, they may design a special tool for the standard tool kit.
Regards

[Ropetangler]

Grahame I can assure you that computers don't "yell" at anyone, they're a tool to accomplish a task. I can also assure you, that any mechanical engineer worth his/her salt working on a design such as you've used as an example would know full well just how much clearance is needed by a human hand.

I think what some people missed, is the emphasis that engineering is all about compromises. That's not to say there isn't bad engineering, there's certainly no shortage of that, but often it's a case where there hasn't been enough (or any, with some copy attempts) engineering input into the final product. Just because you found a oil filter difficult to access doesn't mean that it's "bad" engineering. Maybe one of the design constraints was the volume and specific dimensions of the engine bay made it difficult to impossible to locate it anywhere else.

I think that it's more the case that the engine was designed for a totally different vehicle or even application, and to save costs doing some minor redesign, like changing the location of a distributor or oil filter, the old design is just used as is. In the new application, there may not be access points that were in the original application, so what should be a simple job becomes much more difficult than it should be. While I have no first hand experience of it I seem to remember a report of a Rolls Royce limousine which required the removal of one of the front mudguards, in order to change one of the spark plugs. If true presumably RR thought that if you could afford the car, then regular servicing would not be an issue, and no owner would have to worry about it.
I have had to change hydraulic hoses on a Cat 988 loader by going head first down from an engine hatch, to get to the end hydraulic coupling, and then being hauled out by the ankles when job done. The 988 was a mongrel to work on compared to the larger 992 which in general had much better access.
It seems to me that many manufacturers know that most will only find the bad design points after they have purchased it, and by then you are stuck with your purchase. If you actually knew beforehand you would at least have had the chance to make a different decision if you thought it important enough.

[RayG]

It's hard to be be critical when you don't know what the constraints that the designers were working under. Cost constraints are always a factor in the auto industry. I don't know where serviceability ranks in the order of constraint priorities, but I'm sure that cost and functionality comes first. No point being able to change the oil filter easily if it's so expensive you can't sell it.

That Air France 296 A320 crash was the subject of one of my favourite shows, "Aircrash investigation" Although I notice the youtube video is from the same show under a different name "Mayday", must be aired in some other country under a different title.

Mayday - S09E03 - Pilot Vs Plane - Video Dailymotion (http://www.dailymotion.com/video/x18uqai_mayday-s09e03-pilot-vs-plane_shortfilms)

Moral of the story, don't do a 30' slow speed flyby in a 40' forest..

Ray

[Pete F]

I think Ray is quite right, while I'm just as guilty as the next guy as swearing at the guys who designed something (hey my last car was Italian!), in all fairness I think the engineers themselves cop flack they don't always deserve. We typically don't know he constraints the engineers operated under. Maybe they needed to fit engine ABC into engine compartment XYZ, the latter's dimensions provided courtesy of the marketing department? As the final consumer we're rarely privy to what the constraints were at the time, hence what compromises needed to be made.

I guess if you extend the definition of "engineering" to mean the whole design process by all departments, criticism is often well deserved, but I do often think the poor old engineers cop a lot more criticism than they often should.

[wheelinround]

Grahame I can assure you that computers don't "yell" at anyone, they're a tool to accomplish a task. I can also assure you, that any mechanical engineer worth his/her salt working on a design such as you've used as an example would know full well just how much clearance is needed by a human hand.

I think what some people missed, is the emphasis that engineering is all about compromises. That's not to say there isn't bad engineering, there's certainly no shortage of that, but often it's a case where there hasn't been enough (or any, with some copy attempts) engineering input into the final product. Just because you found a oil filter difficult to access doesn't mean that it's "bad" engineering. Maybe one of the design constraints was the volume and specific dimensions of the engine bay made it difficult to impossible to locate it anywhere else.

Your right Pete ones worth the salt are... trouble is not many round these days even less of them who have ever touched a spanner let alone got down under a vehicle when its all together and stuck their hand in to see if it and a socket, spanner could undo whats required.
Never had to remove the starter motor, gear box etc etc etc when it altogether
Or even a headlight globe such as on my Subaru Forester 2 service technicians/managers ex mechanics now have taken 40 mins each time to replace a globe which should by the book take 10mins. Why did it take 40mins because the battery wasn't there when they timed the work to be done which is what engineers do.

In working at a company who built the Commadore Ute Ambulance (which should never have been allowed on the road). 1st one's built to short in the ute tray for comfortable fit of the patient bed. Shocks and springs well under rated for total package load. I had phone call from smash repairers "How do we remove the fibreglass shell from the body"? The 1st 50 had been mounted so the outside shell was fitted first, bolted to the top rail, then the inner skin fitted and sikaflexed?/glued together, NO access holes to undo the mounting bolts :doh:

3 ute extentions latter and 4 set of shocks springs etc to accommodate a fully loaded with passengers and patient they pulled the pin and went to the Merc van. I could tell you the political reason the switch between Ford f series and Holden if you like.

MAN 40ft tag axle coach rear engine ZF gear box to remove the clutch companies who bough the vehicle called in the sales man and team of MAN engineers to ask "How do you remove the gear box to change a clutch"??? Leading rear axle had to be totally dropped and removed to allow the removal of the gear box. of course it had all been computer designed. gear box installed on line by overhead gantry.:roll:

Bean counters do not spec bearings nor do they spec load limits engineers do.


I will say one of the greatest feats of engineering designed (not by an engineer Uni trained) is the King Pin of a semi trailer 3"dia is all that holds on a trailer or team of trailers.

Being a wheelchair user the hassles I have had with this chair from new and alterations I have had to make for $1,000.00 outlay is disgusting. The engineer where I purchased couldn't see the fault with the foot plates swung in retraction mode hitting the break leaver and knocking it into off mode.:oo: Nor the fact the front wheels were trailing not leading in front of pivot point this had the reaction of lean forward and I'd be on the ground change the wheels easy bu then the foot plates were to short to fit.


Machines and design are in many cases not much better look at how many fellows just on this forum alone have to alter, fudge, re-build new machines to have them work some are not cheap either.

[A Duke]

Hi,
Talking of spark plugs, to access the back 2 plugs on the Sunbeam Tiger you did it through access holes under the dashboard. I suppose you expect a bit of fun when you buy a car with a 4.2 litre V8 when it was designed for a 1.5 straight 4. The base for the Alpine / Tiger was from the Hilman Husky.
Regards

[Michael G]

(For someone trying not to defend engineers I'm getting deeper and deeper...)

Firstly, there are good engineers and bad engineers. These days there is so much stuff an engineer is meant to know about and such an emphasis on computers that there is no longer much hands on stuff for the kids going through engineering school - but then again there is no pay off for the Uni's if they do have those facilities available anyway. At our factory when we have students there on work experience the first 3 or 4 weeks are spent pretty much 100% on hands on just to get them used to the idea.

As a few people have said, engineers are subject to a whole bunch of constraints, mostly on cost - while Bean counters do not spec bearings nor do they spec load limits, they certainly stop engineers putting in the solutions they would prefer to have. One noise problem that I saw an engineer struggling with for months was eventually found to have been caused by cheap low spec bearings. In the mean time tell the bean counters that you want to spend more on suspension before a problem has been proved and see how far you get.

Yes, I've worked in a car manufacturer and interacted with the design guys there. However, a lot of this stuff is set in stone way before production get to see it and only a major stuff up will stop the program. Most car companies back the stylist if the engineer says that he/ she needs more room in the engine bay. What are you going to do?

Lastly, servicing - the space available is dictated by the shape of the car. Servicing is assessed at design time and there are always trade offs - but then the car companies want you to use their dealers so they don't really care if the average person has a problem changing the oil or plugs. The dealer with the flash tooling is alright though.

Michael

[Pete F]

Yes I agree Michael, I would consider it highly unlikely that an automotive engineer producing a mainstream car would have, as part of his/her brief, that the part needs to be easily serviced by a guy in his home workshop.

I'll throw up an example of how good I think engineering is in general in this field. Look at the warranties these days, many are 100,000 km. That in itself is very good, but more the point is that the vehicle typically gets to 100,000 km without too many issues at all, mostly none in fact. Very soon after that period quite often they'll start developing issues where parts will require replacing etc etc etc. Now for us as customers many might thing that it's bad engineering, but I think it's absolutely brilliant. The brief is clearly to produce a product that will reach that period, and after that anything extra typically adds weight/cost/etc. Just consider how cheap vehicles are in terms of average weekly earnings compared to a generation ago! The fact that so many get to exactly that defined warranty period (ie it's "just enough") takes considerable skill in my opinion.

Doesn't help you much if you buy the vehicle at 120,000 km though :D

[wheelinround]

Michael your right just as Pete.


Nothing like a backyard mechanic Pete without them we wouldn't have many motor sports we have today.

The word Engineer has changed so much since I was a kid well its meaning anyway.
Even the Engineers Institutes have all but gone last one I saw the building was in Tamworth or was it Toowoomba recently.

If I had had the pleasure of going on further in education it still would have been hands on I'm a tinker at heart have always been so. Just life throws things in a whirl wind and you never know where you end up.

[Ropetangler]

I think Ray is quite right, while I'm just as guilty as the next guy as swearing at the guys who designed something (hey my last car was Italian!), in all fairness I think the engineers themselves cop flack they don't always deserve. We typically don't know he constraints the engineers operated under. Maybe they needed to fit engine ABC into engine compartment XYZ, the latter's dimensions provided courtesy of the marketing department? As the final consumer we're rarely privy to what the constraints were at the time, hence what compromises needed to be made.

I guess if you extend the definition of "engineering" to mean the whole design process by all departments, criticism is often well deserved, but I do often think the poor old engineers cop a lot more criticism than they often should.

I would agree with you Pete on this. Often the senior management, people managers, not engineers are the real cause of these issues. As I recall when Rover introduced the Range Rover, which was very innovative in design for the times, it quickly took off in the sales charts, and demand outstripped supply. Instead of ramping up production ASAP, BLs head, Lord Stokes said to increase the price by 100 pounds per month, until supply and demand balanced. In a few short years, other manufacturers introduced their own innovative design changes, and Rover lost their design lead, and sales dropped in proportion to what they had been.
Another example on which I had a very minor part was in the Electrical Engineering field. Some years ago now Tasmania and Victoria linked their electrical networks by constructing BassLink. The idea being that as Tasmania had almost 100% hydro electric power, and Hydro power stations can be spooled up in a couple of minutes from 0 to full output. Victoria had mainly brown coal fired power stations which do not like having their outputs varied quickly to match power demand, so it made sense to have Tasmania supply peak demands with hydro power, and Victoria to supply base load from their coal fired stations. Tasmania was to send power to Victoria during peak times, when the power stations would be run flat out. during times of minimum load, power would be sent back from Victoria to Tasmania, and as much as was possible, the hydro powered stations would be throttled back. It would not have been possible to turn them right off as the BassLink cable did not have the capacity to carry the full Tasmanian load. They even refurbished and IIRC replaced some turbines with higher capacity units, with the idea that as they would not be running 24/7 at near full output, they could be run even harder in short bursts without us running out of water, in order to satisfy the peak.
To cut to the chase, a lot of my time was spent assembling components in the switch yard. There were perhaps 10 parallel circuits comprising circuit breakers, capacitor banks, inductors and other large bits and pieces, all connected together with multistrand Aluminium cable, and my supervisor from Siemens was tearing his hair out because instead of the terminations on each component pointing toward the next one in line, they might be in excess of 90 degrees out. the only way that you could get the cable to run from one terminal to the next, without birdcaging, or kinking was to pre-bind the length of cable with fibre reinforced packing tape as tightly as possible, connect one end, then bend it around and clamp the other end loosely, hacksaw off the protruding inner cores, and then tighten the clamps fully. we then removed the packing tape, and cleaned off any adhesive with solvent. The supervisor said that until a couple of years earlier, they had an experienced field engineer looking after the assembling of components back at Siemens in Germany, but that he had been pensioned off for cost cutting reasons, and that he had been replaced by a recent graduate, who using Autocad, could run a line from A to B with a couple of mouse clicks.
You couldn't blame the young bloke, he'd been thrown in with no experience or guidance, and had just done what he had been taught at university. If he had been sent out on one field installation first, he would have had some practical experience to go on. Big egos and toxic personalities can also cause these situations, as some hate being told by others with specialised knowledge like engineers and technicians what is or is not possible or reasonable etc.

[A Duke]

Hi,
"Big egos and toxic personalities" Like the types that know so much they don't even know there is stuff out there they don't know.
Regards

[Pete F]

I don't watch much television, but my wife generally has it on. Last week I sat down in the evening and watched a program on restoring a Triumph Stag. I quite liked the show, but have always regarded them (and especially the engine) as a complete POS! They were notorious for overheating. Dodgy engineering was always blamed for that, and while there was certainly no shortage of that in this car, the program showed that in fact there was nothing at all wrong with the cooling system of the car, provided it was installed and maintained correctly. I always got the impression the engineers were pushed around a lot on that project, and yet in the end copped the blame for a lot of problems that really were beyond their control.