Not fit for purpose

Hi There

Looks like the long links have been disabled.

I posted a link and it came up as **link** and it did not appear to work.

So, please use the link function to insert link.

I assume this is a designer change.

regards David

Who would even dream of asking if a set of drawings were fit for purpose ?

Is it the guy in front of me who goes into Sainsburys and pokes every apples so they are bruised ?

Is it the guy who squeezes every loaf of bread so the one I pick up is work hardened to 65 Rockwell ?

Come on guys the mantle of the anorack wearer is fast becoming transfrered from the train spotter to the Model Engineer.

I think that anyone buying drawings or plans could reasonably expect at least an additional slip of paper listing any available corrections.

A few years ago I bought a quite expensive book on the construction of a clock, which contained many unclear statements, some printing mistakes and much out-of-date information. I wrote a letter of complaint but received no reply from the author.

I expected the challenge to be in the making of the clock, but it is in understanding the book.

Ah new software! These days software is not 'released it just 'escapes'!

Rdgs

Dick

Unfortunately ME plans are no different to anything else, whether it be electronic circuits (and/or PCB's) computer software or what have you.

I have been into electronics for many years, you would be surprised at the number of 'Published projects' that may be complete with circuit diagram and PCb layout, that have never actually been built to prove they work. The ones that have actually been built will usually suffer from wrong part numbering, wrong part value, PCB that needs correcting etc etc.

This can be very frustrating, especially for a begginer, as you might imagine.

One's first approach to a plan or circuit will usually assume that everything will be correct, only experience will make you wary about taking that assumption for granted.

I understand the writers frustration, but at what point does a plan become 'not fit for purpose'? how many mistakes are allowed? What about minor mistakes to major mistakes?

Over a period of time one would expect corrections to be published as the number of people build to the plan, but these people have managed to suss out the errors so why not you/us?

As with anything you buy 'caveat emptor'' applies.

I have tended to look on plans etc as design ideas rather than completely accurate projects, for the above reasons, the more complex the plan/design the more likely I would be to do a lot of cross checking before taking a single cut.

Always assuning the worst, will lead to less frustration in the end, (the proverbial 'pinch of salt'.....)

What a lot whingers. I've purchased drawings from Myhobby Store and found them to be OK. Surely you examine the drawings before you build. That's a normal standard. Any mistakes can be then sorted out and marked on the drawing. It's not very hard. I worked on laser, radar, and infra red absorption analyis and circuit diagrams from the manufacturer had mistakes, but it was up to you sort them out.

For the price of the plans I think they are of good value. As others have stated, use your brain. You will soon learn how to interpret the drawings and this I feel is a great benefit. By doing so, you will soon be able to sketch up your own.

Don't blame David. He does a damn good job!

Regards

Richard from South Australia

Normaly I wouldn't go against Davids opinions since I've found him to be very fair. His first comment was to me rather humerous also.

I can see and understand a new design having mistakes within it. That's understandable. While I don't know the exact process used to print the drawings today that My Hobby Store sells, and I'll refrain from getting into the fit for purpose issue. I do have a issue with the old drawings that contain well documented mistakes.

The George Gentry designed Model Engineer Beam Engine for example contains at least 11 mistakes that I know of. These drawings have remained unchanged for at least 30-40 years and possibly much longer than that. AFAIK Revees and My Hobby Store still sell these drawings without including a single additional sheet with those corrections listed that would be most welcome by any builder, and in todays world it would be almost impossible to add more than 10 cents in cost. I'm certainly not faulting David for this since it's not part of his job and the needed corrections should have been done decades before he became editor. So to be a bit logical about this? My Hobby Store, Revees, and any other supplier of drawings we use do have an obligation to at least correct the drawing mistakes as there found. Instead those mistakes are generaly ignored, and year after year different builders get the joy of rediscovering those same mistakes again and again. That is and would be a comman and important item for any company that cared about their customers perceptions in my humble opinion. That's not too much to ask from any company no matter what they sell. Or at least it shouldn't be if they want to remain in business today. As the end users and the people who keep Model Engineer and Model Engineers Workshop magazines going. I think we well deserve that minimal amount of attention to what My Hobby Store is selling to us. Any older drawing should by now be 100% correct. To say otherwise is illogical.

Pete

Edited By Pete on 30/06/2012 09:26:56

Pete,

Excellent comments !

However, in the absence of Errata from the Publisher ... perhaps this forum is the place to log all of those errors & omissions that builders find; together with their proposed fix.

MichaelG.

[David Clark 1]

Would you be prepared to create one thread for each of the available drawings?

... kept specifically for this purpose, and using the Drawing Number as its title.

Edited By Michael Gilligan on 30/06/2012 10:18:29

Hi Michael.

We can do that.

Not a problem.

Pete, there is a problem.

We cannot change drawings because people point out errors. Repeated errors have been checked in the past and not all of them were actually errors, just builders misunderstanding the drawings.

If we did change the drawings, we would have to build the entire model from scratch to ensure it was an error and also that we had not introduced further errors. Clearly this is not possible.

regards David

Edited By David Clark 1 on 30/06/2012 10:44:15

Hi There

Topic now set up in general discussions.

regards David

Thanks David,

Much appreciated

Provided you can keep posters "on-topic" ... I think that's a practical way forward.

MichaelG.

Link to Topic

Edited By Michael Gilligan on 30/06/2012 11:48:31

The Model Engineers Clearing house web site has had a post up defining known faults for ages but it still doesn't stop this subject being raised time and time again.

If you search most popular plans have pages where corrections are listed.

However as David has said many are not mistakes but errors in reaing and this then spawns further posts where someone is usually told to go to specsavers.

John S.

Thanks John ... I was unaware of that.

However,I still think it "proper" for the ME/MEW forum to host its own review of the drawings.

MichaelG.

I think that if anyone has a problem with a published drawing, they could after building the subject of the drawing, redo it, and foreward it to the publisheras an updated and corrected version (and hope to h**l theres no misstakes). In my oppinion, just get on, its part of engineering, you get misstakes in the big boys world too as pleant have found. Ian S C

I do find this all mildly amusing. From what I can see this topic of errors on plans seems to crop up regularly and has no doubt been a problem from issue 1 of ME. I consider myself a beginner albeit now with 2 years behind me. I've built the Northumbrian and it runs, I didn't use the plans, just the magazine articles. Before I started I asked if there were any problems and David, Jason and others pointed me at all the known issues. In my journey I found more and published them on the Northumbrian thread.

My point; It’s clear there have always been errors in drawings, there always will be. In the past model builders either put up with it and suffered in silence or wrote a letter to the editor and may or may not have got a reply in a subsequent issue. No doubt some months later. We now have the Internet so we either use it as a means for near real time whinging or better use of the forum and report and check for errors. No need for re-prints, or rebuilds to check corrections, just everybody contribute errors as they find them. Subsequent builders can check and confirm for themselves if the reported issues are material or not.

That said MHS still has a duty to ensure the quality of published plans but won''t find everything so “Buyer beware”.

Pete

Yep - exactly so. Drawings of any significant complexity share this characteristic with software - the one thing that you can always say about a piece of software is that it has bugs. Interestingly, as David has observed, every time you attempt to fix a bug in a programme (or a mistake in a drawing) you run the risk of introducing more problems that weren't there before, whether or not the original bug gets fixed in the process; also, the fact that a "bug" has been reported is no guarantee that the problem reported really is a problem or just a misinterpretation on the part of the reader/user.

Consequently, maintaining software of any kind, be it drawings, programmes, or whatever else, is a non-trivial problem, and frankly, one that My Hobbystore as an organization isn't geared up to handle - if it was, you could probably add a zero onto the price of the magazine (seriously), and I don't think any of us, including My Hobbystore, would be up for that.

IBM used to track the rate of bug reports on each software package they released & it goes through a repeatable pattern - initially, a high rate of reports (and fixes to them) when the package is first released, then it plateaus out as the major and obvious bugs are dealt with, then the rate starts to rise again as the fixes to the more obscure bugs start to generate more problems than they solve. At that point, they used to stop attempting to fix any further bugs, and (if necessary) started work on a total rewrite. But the point here is that you will never reach the point where there are no bugs to fix.

So, "Fit for purpose"? Most definitely yes - the purpose of the articles & designs published in these mags and in the re-printed plans is to provide a starting point and ideas for the budding Model Engineer to work with and to develop his/her creative abilities; emphasis on "starting point" and "Engineer" here - they aren't intended to be instructions provided to a production team in a factory. If you are expecting to be able to follow one of these drawings blindly, without applying any engineering thought and without checking that everything you see on the paper is correct, then it is YOU that is not fit for purpose, not the drawing.

I have built things over the years from various articles published in the various ME mags and books; I don't think there has been a single instance where I can say, hand on heart, that the drawings/build instructions were 100% accurate; equally, there hasn't been a single instance where I haven't said to myself "There's a better way of doing that" and followed a different path. Sometimes the different path has proved to be a dead end, and I have realised that I should have done what was suggested; other times, my ideas have improved on the original. Either way, you come out of the process knowing more about ME than when you started, and to me, that is the real purpose.

Regards,

Tony

Edited By Tony Jeffree on 01/07/2012 12:42:21

Very good post Tony.

This "fit for purpose " handle is abused no end nowadays but there are two sides to the story.

Said Herbert rushes into Machine Mart / Warco / Arc / Chester [ delete as nessesary ] and buys a lathe / miller.

Takes said item home, unpacks it and starts to knock lumps of metal but because of his / her inexperiance nothing comes out as it should.

So play the "unfit for purpose card " but how does the seller know the USER is fit for purpose ?

Take a car, you need training or having to pass a test to use it on the road. Personally i have met people who i wouldn't trust with a toothbrush.

John S.

One thing, in the very early days of ME you (well your great great grandfather could) could write in, and if your letter arrived even just a few hours before printing time it could be included in that issue, and possibly a reply also, so that within a week of an artical appearing, you could ask about a misstake in a drawing, and have it corrected. Thing have changed a little since then have'nt they. Ian S C

Hi, I'm no expert in CAD, but for a few years now I have used a cheap CAD programme to plot out my family tree in the old traditional way, which I can then print out on my A0 printer. This has not presented me with any significant problems, but as more information was added I found that errors were creeping in. It turned out that the errors were induced by myself by not realising that information that was already in the programme were accidentally highlighted while adding new information. Following on from this, I continued to be vigilant as to make sure that nothing else was highlighted while adding or updating more information and checking everything before saving, however, as the tree became bigger, the task of maintaining correctness became more involved.

Even when I got to the stage of the first printout, and checking everything before hitting the start printing button and then reviewing the the printout afterwards and believing it all to be OK, errors were found when other members of my family viewed it.

So yes even when you believe you have done everything correct and there is no one else to blame, errors can still creep in and it takes more scrutiny to make sure you don't make more errors when correcting those that you find, especially when the programme gets more complex.

Regards Nick.