Why do designers do this!!

[Peter Cook 6Participant @petercook6]

I swapped the dampers on my old (25years) Bosch washing machine today.

Four bolts. Two at the top holding the dampers to the drum. Two at the bottom attaching the dampers to the frame. All installed with captive nuts in U shaped brackets welded in place. Three of the bolts are installed from the back of the machine. Simples – socket on long extension bar and a reasonable amount of force freed them off.

But one is installed the other way round. Bolt head facing the front of the machine. Very awkward to get at from the back. And that one seems to have been fitted by a 600lb gorilla with a four foot bar!

After four hours of struggle I relented and disassembled the front of the machine. Long extension socket bar and a 1 metre length of 6mm steel bar as a t-bar finally shifted it. Modern machines use plastic pegs – so limited stress. One hour later it's all done!

Why oh why couldn't they have installed all four the same way round?

Edited By Peter Cook 6 on 06/09/2021 21:17:47

[Peter Cook 6Participant @petercook6]

Installing bolts backwards!

[Mick B1Participant @mickb1]

Posted by Peter Cook 6 on 06/09/2021 21:13:18:

….

Why oh why couldn't they have installed all four the same way round?

Edited By Peter Cook 6 on 06/09/2021 21:17:47

It's a mystery. Likely to do with speed of assembly.

I always wondered why the bolt securing the brake master cylinder on the Moggie Thousand was put in from the torsion bar side so you couldn't withdraw it straighforwardly after removing the nut.

Why did I have to take the entire entrails out of my old tumble dryer in order to get at the door microswitch?

[Anonymous]

Not clear to me from your description whether this is an assembly problem (i.e all four bolts could have been fitted the same way but one wasn't) or a design problem (one bolt has to be fitted reversed by design).

[bernard towersParticipant @bernardtowers37738]

the reason for that Mick was that a skinny headed bolt was easier than only 2 or 3 threads and a skinny nut. never had a problem myself just used the torsion bar pulling tool and slid the bolts out. But I do get your drift it was a stupid bit of design.

[Ex contributorParticipant @mgnbuk]

It's a mystery. Likely to do with speed of assembly.

No mystery – it is all to do with ease & speed of assembly. Serviceability really doesn't come in to it – manufacturing plants make new stuff, repairing older products doesn't keep the lines running. Making products easier to service would increase assembly time & cut profits.

Cars are similar – having been round the Audi car plant at Ingolstadt & seen the way that cars are assembled, it is no wonder they are a pain to work on. For example, the battery was installed before the complete front of the car was fitted – the line worker had free access to pop the battery in place as the front section containing the headlights, radiator etc. was not fitted at that point. Bolt the front of the car in place later down the line & the battery is buried. No problem for Renault's assembly plant and bean counters that the engine had to be removed to change the cam belt, as was the case with a Laguna company car I had.

Nigel B.

[Mike HurleyParticipant @mikehurley60381]

Same with my Diesel Ford Kuga. You have to dismantle 1/2 of the engine bay to get at the battery.

Wish I'd taken it to Halfords* for one of the 'free' fittings and see how they got on! Took me about 3 hrs including some wierd tool combos to access some bits!

regards. Mike

* other auto parts suppliers are available

Edited By Mike Hurley on 07/09/2021 09:45:51

[ChrisHParticipant @chrish]

Why do designers do this?

Because they are ignorant with absolutely no practical experience, wet behind the ears and have never had to actually work on the item they design, to take it apart or maintain it; if they did then they would very quickly redesign it.

Thats why!

Chris

[larry phelan 1Participant @larryphelan1]

I think Chris has got it in one !!

[Ex contributorParticipant @mgnbuk]

Because they are ignorant with absolutely no practical experience, wet behind the ears and have never had to actually work on the item they design, to take it apart or maintain it; if they did then they would very quickly redesign it.

I disagree.

Designers & production engineers are not stupid people & if it were made a part of their remit then I am sure that they could incorporate serviceability into a design. But their remit will be to design it to be as easy and as cheap as possible to make and capable of outlasting the warranty period before repairs are required. That the design requires, say, the removal of a front wheel, wheel arch liner & heaven only know what else to change a headlight bulb in the field will be of no concern, as long as it can be fitted easily on the production line.

Designers & production engineers dance to the tune of the bean counters in the first instance, not the end user.

Nigel B..

[Anonymous]

Posted by ChrisH on 07/09/2021 09:49:16:

Because they are ignorant with absolutely no practical experience…………………

That in itself is an ignorant comment.

I'd agree with Nigel, but go further and say they definitely dance to tune of the end user, who often buys on price.

Andrew

[Peter Cook 6Participant @petercook6]

Peter G, it was a design issue. The bolts hold the damper into a U shaped bracket at each end. One leg of the U has a captive nut welded in. The other is a clearance hole for the bolt.

Three brackets are welded in place so that the nut is at the front of the washing machine and the bolt inserted from the back. One is welded in place so that the nut is at the rear of the machine and the bolt has to be inserted from the front.

There is nothing in the way at the back, so the bolt could have been inserted the same way round – if the bracket had been welded on the other way round. But it wasn't designed that way!!

As people have said its probably designed the way it is for the assembly process – but it really is a pain to service.

On the bright side on this machine the bearings are in a spider bolted to the back of the drum so changing them doesn't involve completely dismantling the machine as in more modern ones.

[Nick WheelerParticipant @nickwheeler]

Posted by Mike Hurley on 07/09/2021 09:44:48:

Same with my Diesel Ford Kuga. You have to dismantle 1/2 of the engine bay to get at the battery.

Wish I'd taken it to Halfords* for one of the 'free' fittings and see how they got on! Took me about 3 hrs including some wierd tool combos to access some bits!

regards. Mike

Halfords have long had the policy that if they have to remove mechanical parts, they don't do the job.

I've fitted several brand new Halfords batteries to Mondeos in Halfords carparks for that reason. The part in question? The Air Flow Meter that needs a Jubilee clip to be loosened to move it out of the way. Easier than fitting a Corsa battery on the scuttle, even if the captive nut in the plastic shelf is still captive.

[Nicholas FarrParticipant @nicholasfarr14254]

Hi, I can't say that I've known washing machine dampers needing replacement, the machines normally wear out past their design life with other things first. Production times are very often included in the design to keep the purchase price as low as possible and such designs can save a few seconds on assembly times, which you might think is a bit trivial, but when you consider the time saved after making a few thousand units it makes sense. I visited the Nissan car factory many years ago and all their assemblers were encouraged to put forward any ideas how time could be saved, even if it was only one second per operation. I suspect the manufacturer considered the number of dampers that would ever have to be replaced would not outweigh production costs.

Regards Nick.

[John Doe 2Participant @johndoe2]

I have changed washing machine dampers.

Haynes manuals would sometimes state something like "Remove rear number plate", as the first part of a job involving the engine !

It used to be a point of satisfaction and pride to be able to perform the job without all the extra steps !

I can't remember which engine maker it was, but some years ago, an aircraft engine manufacturer invited aircraft engineers to see the mock-up of the latest turbo-fan engine, and comment about how to make routine line servicing of the engine easier by re-siting or re-orienting components etc.

Edited By John Doe 2 on 07/09/2021 11:08:26

[Peter Cook 6Participant @petercook6]

Posted by John Doe 2 on 07/09/2021 11:07:07:

I can't remember which engine maker it was, but some years ago, an aircraft engine manufacturer invited aircraft engineers to see the mock-up of the latest turbo-fan engine, and comment about how to make routine line servicing of the engine easier by re-siting or re-orienting components etc.

That would be the bean counters again. Aircraft engines are usually supplied by the maker on a full service basis – so making them easier (cheaper) to service would be in the makers interest. Household appliances on the other hand…!!

[Mick B1Participant @mickb1]

Posted by bernard towers on 07/09/2021 07:34:48:

the reason for that Mick was that a skinny headed bolt was easier than only 2 or 3 threads and a skinny nut. never had a problem myself just used the torsion bar pulling tool and slid the bolts out. But I do get your drift it was a stupid bit of design.

Long while ago now, but I think I used a big crescent wrench or bar to strain the torsion bar aside far enough to get the bu99er out, but had to put on more force than I liked. Obviously I put bolt back t'other way about.

[mark costello 1Participant @markcostello1]

The longer it takes to change something out, the more the dealer (stealer) gets to charge.

[Nigel Graham 2Participant @nigelgraham2]

With cars of course the value-engineers have had their go at at it, and the stylists have to – well, are paid to – make the exterior look as snazzy and saleable as possible. If their unholy combination results in having to take half the bodywork apart to change a lamp…. tough.

I have a Renault Kangoo and have just had to pay a lot of brass better spent on model-engineering to replace the worn-out, possibly original, HT components (now at >50 000 miles). A task that years ago would have been obvious to diagnose and a couple of hours' work for any motorist with basic maintenance knowledge. And as for the so-called "cabin air filter"…. Goodness knows where and how that's hidden! I found several amateur videos showing the secret but they revealed only any edition of the Kangoo except mine, and all different.

Ironically the bureaucrats keep insisting on tighter and tighter "type approval" rhubarb, but the concept of making it easy for the owner to keep the car legal even when on a cold, wet dark Winter Saturday night, and far from an over-priced main-dealer, seems lost on them.

[BazyleParticipant @bazyle]

Cleaned the boot carpet today (side effect of checking spare tyre pressure). Why do they design it with special pile that clings to sawdust and general dirt. On the other hand the outside paint does seem to be designed to shed dirt such that I only wash it once a year unlike my car 40 years ago that needed weekly washing even if I didn't drive it anywhere.

[duncan webster 1Participant @duncanwebster1]

No, it's specially designed, along with all the other upholstery to make removing dog hair impossible. I've tried special brushes, vacuum cleaners, parcel rape, nothing shifts it. Fortunately I don't do it very often!

[Kiwi BlokeParticipant @kiwibloke62605]

Absolutely agree with Nigel B.

Another favourite trick of car design is to put loads of expensive and fragile components right behind the fragile plastic 'bumper' (misnomer), so the whole lot is trashed when granny in a supermarket car park reverses into your car. More spares supplied = more profits. The insurance companies know all about this, but compensate by raising premiums. The consumer doesn't count, once the product is bought.

Edited By Kiwi Bloke on 08/09/2021 03:40:06

[bernard towersParticipant @bernardtowers37738]

Sorry Mick B1 but not enough room to get a flat washer ,spring washer and full nut behind the torsion bar especially as there is a further 2 or 3 threads sticking out. The correct way to move the torsion bar out of the way is by bolting a plate under the g/box x member bolts with a couple of ins sticking out under the torsion bar. This plate has a hole in it to take a hook bolt 3/8 ins in dia, hook the bolt over the torsion bar and thru the hole in the plate, fit washer and nut then tighten until torsion bar is low enough to slide bolts out. Done dozens of them over the years, had to cut my teeth on them as an apprentice.

[Robert Atkinson 2Participant @robertatkinson2]

There are many reasons for "bad" designs. As noted what is good for production may not be good for repair. White goods are different from carsand cars a different from aircraft.
Requirements for cars can change. I remember Vauxhall making a big thing of one of their cars (Cavalier I think) being able to have the clutch changed without removing the engine or gearbox. This gave them an advantage in the company car market (now insignificant compared to private) where running costs are important. Now it's about the wireless system and variable colour mood lighting.

Many years ago I checked (for radio aspects) a antenna installtion on a business jet. It was in the middle of the roof and used 6 screws with loose nuts inside. A asked the "designer" why the didn't use captve nuts becuase changing the antenna or doing checks on it would mean removing the one piece roof lining which in turn need the seats and side paels to be removed.
The reason? He could not find a stencil for the captive nut! This was pre-CAD.

The other reason I hate is "we always do it like that"

Robert G8RPI

[Mick B1Participant @mickb1]

Posted by bernard towers on 08/09/2021 17:58:56:

Sorry Mick B1 but not enough room to get a flat washer ,spring washer and full nut behind the torsion bar especially as there is a further 2 or 3 threads sticking out. The correct way to move the torsion bar out of the way is by …

That may be a correct way for a repair shop that has to do it regularly, but it doesn't suit the 'normal' owner wanting to repair the seals without a toolmaking diversion. But it still works the same way of straining the bar to create a passage.

If I remember the manual correctly it started the master cylinder disassembly with "Remove the torsion bar assembly…"

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