No 4407 More Errors

[JasonBModerator @jasonb]

Just got in, made myself a cup of tea, sat down to flick through the newly arrived issue 4407 only to find more drawing errors before I’d even got half way through my mug

 

Great Western 5″

 

Dimension top right of upper frame drawing 4.531″

Add up the dimensions on the lower drawing and they come to 4.5″

 

Rider Ericsson

 

Base plate holes drilled on 33.6PCD

Cylinder holes drilled on 33.5PCD

 

Water Jacket 33.5mm diameter

Beam bearing plate which has a curve cut out so it fits the jacket, curve given as 38.5 RADIUS

Same error on pump pad, Water Discharge pad & crank bracket.

 

And where does one get 2.85mm silversteel and a reamer to suit?

 

Will finish my tea now before having a close look for more errors.

 

Can someone at ME at least look at the drawings rather than blindly copying or printing them.

 

Jason

 

Edited By JasonB on 29/06/2011 16:51:56

[JasonBModerator @jasonb]

[JasonBModerator @jasonb]

Bracket clock

 

Fig 14, overall thickness of gear shown as 0.125″

Thinner edge after chamfering 0.165″

 

J

[KWILParticipant @kwil]

Glad to see someone is awake!!

[JasonBModerator @jasonb]

Darjeeling

Nut bottom right page 15

 

Shown as 3/16 long

Also says drill and tap 3/16″ deep

 

Leaves nothing to drill teh 3/32″ hole into

[JasonBModerator @jasonb]

Rider Ericsson Water jacket again

 

It Says in the text that the water jacket is a tight press fit over the cylinder liner. But in my book trying to press a 27.65mm dia liner into a 25.5mm hole is just a bit too tight

 

Could be worse, the lefthand drawing Fig 4 gives the same hole a 22.8mm dia even tighter, this should refer to the width of the pump pad not dia of hole

 

J

 

 

[JasonBModerator @jasonb]

Ryder fig 7

 

Profile of curve shown will not allow part to sit in the correct position on the liner

Height given as 14.5 and 14.3 depending where you look

 

Fig 8

 

Two intersecting holes drawn at same diameter but annotated 3mm & 5mm

Block drawn as a square but dimensioned 10×13?

 

Fig 12

 

8BA thread dimensioned at 3.0mm dia

 

 

Edited By JasonB on 29/06/2011 18:49:06

[JasonBModerator @jasonb]

Ryder Fig 9

 

Heights don’t add up. 1.75 + 7 + 6 + unknown does not equal 13

 

Fig 10

No height for beam axle hole given

 

Fig two

Text says holes in baseplate should be aligned to the centre of the baseplate but all holes are dimensioned 0.02mm off centre

Where is Terry

 

Edited By JasonB on 29/06/2011 18:58:28

[JasonBModerator @jasonb]

Back to the Great Western

 

At least 6 dimensions missing, the pairs of arrows are there but numbers are not.

 

The zero in the 4.093 dimension has not printed as its beyond the fold in the page

Edited By JasonB on 29/06/2011 19:28:37

[Phil PParticipant @philp]

Your post reminds me of when I was first trying to decide which model traction engine to build over twenty years ago.

 

All you ever used to read about then were errors in the published designs, and it was obvious that these designs had never actually been built prior to being published.

 

As a mechanical design engineer by profession, that was just not good enough for me and I made the decision to do my own design, drawings and patterns etc of a previously un-published traction engine.

That was a Ruston Proctor Class SCD tractor in 3″ scale, That way I could only blame myself for any errors encountered.

 

At the same time I cancelled my subscriptions for ALL of the model engineering magazines, as they were not really helping me in any way, and to be honest were just full of adverts and regurgitated rubbish from previous years.

 

Obviously I made a good decision, because it looks like things have gone from bad to worse.

 

I never make anything these days unless I have personally designed it myself, or converted an existing design into a Solidworks 3D design to make sure it is correct.

[,Participant @nousername29627]

Funny how all the exhibitions are full of items made to such awful drawings. Maybe theyre made by craftsmen/women/people.

[JasonBModerator @jasonb]

Are they full of them, I’ve been going to the ME exhibition for about 30years and the number of models has certainly fallen, a large proportion of those shown are by the author of said articles.

 

As crafts are no longer taught in schools how can we continue if beginners are not given the correct information to work to. Once they have the experiance then they will be able to use this to acertain what most of there errors should be until then I will continue to point out any errors that I see in the hope that they will be corrected for the benifit of others.

 

Jason

[David CostelloParticipant @davidcostello75947]

Hi Jason

Its wednesday night you should be in the workshop.

Dave.

[JasonBModerator @jasonb]

I know I should and I have not written any more about that hit & miss of mine.

 

Workshop was a bit too hot tonight anyway so can’t finish the drip feed oiler i’m scaling down from a full size, should be fully functioning even though its only 7/16″ dia.

 

J

[,Participant @nousername29627]

1069 posts – he should be there every night

[Jeff DaymanParticipant @jeffdayman43397]

Place your bets now on how long it takes the editor to offer the standard responses about errors and bad drawings:

 

“we can only publish what drawings authors send”

 

“we don’t have time to check drawings”

 

“Looked OK to me”

 

“our illustrator has too much workload”

 

“magazine drawings can’t be done to industrial standards”

 

Wait and see….

 

JD

 

PS before cutting metal on any published design I repeat/endorse the suggestion above about laying it out yourself on a CAD package. Otherwise you will be scrapping some parts and remaking them due to errors. Some errors and crap drawings have been around (and worked around) for 80 years or so!

 

As to exhibition models my hat is off to those with skills and patience enough to finish a model with the frustration of erroneous drawings and getting past the remaking of scrap parts.

 

In my opinion the model press should strive to publish the most correct drawings possible, not sweep crap under the carpet and make excuses.

 

 

[JasonBModerator @jasonb]

” Place your bets now on how long it takes the editor to offer the standard responses about errors and bad drawings:”

 

 

Don’t think you will get very good odds on any of them.

 

Just one thing in my first post I said the jacket was shown as 33.5mm, it should have been 38.5Dia, same problem with the other bits shown as 38.5R, thats what comes with tying to type with a mug of tea in one hand

 

J

Edited By JasonB on 30/06/2011 07:29:10

Edited By JasonB on 30/06/2011 07:29:39

[KWILParticipant @kwil]

Well Jason, that has been quite a marathon and I do not suppose that is the end. Some time ago I was about to make something as part of a published drawing, “You’ll have to watch that “I was told,”drawing’s full of error as much as 1/4″ out!!”. I redrew the parts concerned and far from it being in error to that extent there was in fact 1/32″ of total tolerance available on the right side.

 

As others have said in this thread, draw and check, even if not obvious , as Jason’s findings are.

Edited By KWIL on 30/06/2011 09:19:04

[John Stevenson 1Participant @johnstevenson1]

Have you given any thought about putting the mug of tea down ?

 

John S.

[Eric CoxParticipant @ericcox50497]

From Jason

 

Fig two

Text says holes in baseplate should be aligned to the centre of the baseplate but all holes are dimensioned 0.02mm off centre

 

That equates to 0.000787 inches ! ! !

[KWILParticipant @kwil]

An error is an error, whatever the size!

[David Clark 13Participant @davidclark13]

Hi Eric

The 0.02 is to allow for the thickness of the paint.

regards David

 

[John Stevenson 1Participant @johnstevenson1]

Posted by KWIL on 30/06/2011 10:15:45:
An error is an error, whatever the size!

 

 

Can you even measure that ?

 

On a long bed lathe the curvature of the earth is bigger than that.

 

John S.

[David Clark 13Participant @davidclark13]

Hi John

Yes you can measure that.

I used to make components to those limits, they had to be withing that size and also flat to about that limit.

Then they threw them in a zinc plating vat.

I am sure that helped to retain the size.

regards David

 

[JasonBModerator @jasonb]

Posted by David Clark 1 on 30/06/2011 10:33:06:

Hi Eric

The 0.02 is to allow for the thickness of the paint.

regards David

 

Problem is whoever drew it up only allowed for paint on one side as the width is 58.8 and the centre line is dimensioned as 29.42.

 

Its just poor conversions from imperial to metric compounded by rounding up and inconsistant working to different numbers of decimal places and significant figures

 

David any chance of sensible answers to all the other errors?

 

J

Edited By JasonB on 30/06/2011 15:58:16

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