Eric.

I've never looked at these drawings, but does My Hobby Store actually state what their purpose is anywhere?

Martin.

Nice one David. Perhaps every plan should come with Blu-tack or drawing pins.

However the hobby has fewer and fewer ex engineers and more consumers who need a sell by date on a tomato to tell them when it has gone off so perhaps checking drawing dimensios is not on the cards.

It will all be solved when then home 3D printer comes with a free 'make me a 5" loco' app.

Hi There

Yes, my drawings are drawn by printer.

I assume stepper motors have armatures so you are totally correct, drawn by armatures.

regards David

Which was my point despite the spelling mistake, and as pointed out the same sort of errors are seen in industry, and many go uncorrected.

I also suspect that some models are made to sketches and drawn up afterwards.

Steve Larner

I think I will stick with David's definitiion of 'fit for purpose' which I read as …

Everything that the 'Artist' put on the original is on the copy (i.e. no edges cut off by the printers, readable etc…), what I do with it after I have bought it is my problem therefor cost stays reasonable – a term that, as a Scot, I will reserve judgment on!

Interpreting your statement

'fit for purpose' = I will get modern, error checked, maintained and updated to meet current professional engineering standards (and may STILL not be error free) therefor cost = 'as for commercial products' = $1000's+ (or in my industry $Millions+) I guess you pay your money and take your choice ..

Personally I would MUCH prefer ME, MEW and the Model engineering community etc stay around.

Let battle commence .

Dave (who is very much an armature Model Engineer).

There is a bigger issue about drawings. Some drawings being sold by several different model engineering suppliers have various errors that have been known and published in several ways for years, but have not been corrected on the drawings being sold. This seems close to dishonest to me, because monies are being paid for goods with known and unaddressed defects. If the drawings were sold with a list of corrections or things to watch for, at least the prospective builder can avoid some wasted time and money. This would be fairer than just plying the same old drawings with errors for good money.

On the other side, in my opinion any drawings bought should be checked carefully by the builder before cutting metal, to avoid wasted time and material. Errors can creep in many ways on all drawings. I have found in many cases it saves a lot of time to make a roughed-in CAD assembly of all parts to check clearances. Usually many things arise which can be improved or simplified on model designs, saving time and making for a better and easier to build model. It is worth buying and learning a good 3D CAD package to do this, in my opinion. Just the ability to print out full size drawings and stick them to stock for direct part layout, especially for sheetmetal, saves much time, guesswork and ruined stock and justifies the cost of the software and the time to learn it.

For the record I am not impressed with the attempted humour in the editor's offhand comments about "decorating" etc. MHS and other vendors are realizing significant profit from selling drawings, and if in fact there are drawings being sold uncorrected, when there is published info about errors available for that particular model, that is less than honest.

JD

Rethink. I had thought initially this was about the usual sort of problem like valve gear hitting something or mistake on dimension on a major project like a locomotive..

However I do believe some plans are so old and crude and made in an era of lower expectations that they are now truely not fit for purpose. The problem being the informtion provided about the item is so superficial that the buyer has no idea how poor the design is. I feel sorry for a junior or 3rd word person for whom the cost is not insignificant and they are thoroughly duped by the vendor and disappointed by the product.

Example 1: MM485 The model submarine plan "Sardine" I actually built 40 years ago. The design is to pre wwII standards in solid wood and tinplate. At 13 I knew no better but now I can see it is unutterable rubbish although technically it can be built to the plan.

Example 2: WE29 I haven't dug out the paper but I once purchased a plan for an "engraver" expecting some sort of simple pantograph. It turned out to be a rod dangling from a support with a needle on the end you were expected to scratch letters with. Totally ridiculous.

Both the above should be marked in the catalogue as "included for historical record, not suitable for construction".

edit to add plan numbers and the following comment:

Bear in mind these were bought before the internet was even  invented. I see the boat still has a deceptively good picture and you can see the engraver plan for what it is.

Edited By Bazyle on 10/05/2012 17:12:34

Edited By Bazyle on 10/05/2012 17:16:59

Hi There

The Northumbrian error was an attempt by the designer to correct and improve the design after the first build.

If it had been left alone it would have been fine.

We have been told of errors on drawings in the past that were non existent. The builder got it wrong.

If we had changed the drawings we would have introduced an error, not removed one.

Short of building the complete model and checking as you go there is nothing we can do about it.

regards David

Hi There

Portable errors were acknowledged.

I set a thread up specifically for portable errors.

We do not just copy and paste drawings.

The majority of drawings are redrawn and we check that they are correct to the author's original.
Occaisonally we spot the odd error and contact the author for clarification.

We do not redesign a project completely. We work on one part of an article at a time. We do not usually check one drawing against another unless something jumps out at us.

We just do not have the time when we are doing 3 magazines every 4 weeks.

If the author gets it wrong, then we will try to print corrections. If there are lots of errors I doubt we would use that author again.

regards David