Any time served Draughtsmen out there ?

[wirey33]

I was trained in the dark arts of Draughtsmanship by a teacher who was previously a Sergeant Major in the Army (so the legend goes…). He drilled into us, by use of the high velocity board rubber, two essential rules A – Do Not Dimension In Between Views and B – Do Not Double Dimension.

 

I’m currently “in discussion” with an Engineer who wouldn’t know what to do with a Rotring ink pen and an ultrasonic bath and he is adamant that there is nothing in the current standards that says you can’t throw dimensions wherever you want. Now obviously, a complex part with many dimensions may become over-cluttered and the draughter should use his common sense to produce a clear drawing; If this means putting a dimension between views, then so be it. But my feeling is that generally you should avoid this when possible.

 

My question to those versed in BS308 and its replacements; is there anything in the standards which says you should avoid dimensioning in between views?

 

 

On a side note, I worked in a drawing office where some of the old boys would wear long “cuffs” over the sleeves of their shirts to avoid getting ink or pencil on their shirts. They had also developed the art of leaning against the enormous drawing boards, pen in hand and fast asleep, usually shortly after a lunch appointment at The Kings Head. When I arrived I was treated like some kind of hero as I was the only one who could work the photocopier J Happy days.

[rab]

I was trained in the dark arts of Draughtsmanship by a teacher who was previously a Sergeant Major in the Army (so the legend goes…). He drilled into us, by use of the high velocity board rubber, two essential rules A – Do Not Dimension In Between Views and B – Do Not Double Dimension.

 

I’m currently “in discussion” with an Engineer who wouldn’t know what to do with a Rotring ink pen and an ultrasonic bath and he is adamant that there is nothing in the current standards that says you can’t throw dimensions wherever you want. Now obviously, a complex part with many dimensions may become over-cluttered and the draughter should use his common sense to produce a clear drawing; If this means putting a dimension between views, then so be it. But my feeling is that generally you should avoid this when possible.

 

My question to those versed in BS308 and its replacements; is there anything in the standards which says you should avoid dimensioning in between views?

 

 

On a side note, I worked in a drawing office where some of the old boys would wear long “cuffs” over the sleeves of their shirts to avoid getting ink or pencil on their shirts. They had also developed the art of leaning against the enormous drawing boards, pen in hand and fast asleep, usually shortly after a lunch appointment at The Kings Head. When I arrived I was treated like some kind of hero as I was the only one who could work the photocopier J Happy days.

Hi,

 

I've just taken early retirement form an engineering drawing office for reasons such as the one you quote.  No one seems to care about standards anymore.

It's even got to the stage where 'you don't need to fully dimension a part, it's being made from the CAD file'.

When a guy from an outside agency told me I wasn't dimensioning drawings correctly, having been doing it for40 yrs +,

I decided it was no good trying to teach an old dog new tricks and got out.

 

As for dimensioning across views, I agree it was not seen as good practice,

but there were occasions, particularly on plastic moulded housings where it was important that a feature on one side was dimensioned

with respect ot another feature on the opposite side;

in these cases I would dimension across views, but only where ot couldn't be done clearly from say a section view.

 

Good to know there are still a few of us from the 'old school around'.

 

Brian

[St. Simon]

My question to those versed in BS308 and its replacements; is there anything in the standards which says you should avoid dimensioning in between views?

 

Hi,

 

I've just done a completed a technical drawing course as part of my apprenticeship using standard BS8888, and I was taught that in this standard you don't double dimension, don't dimension in between views and don't dimension from hidden detail.

 

Simon

[108]

As a Leaving Cert student in the 80's we learnt rules A and B in the OP.

Things have certainly changed for the worse.

[Jeff Smith]

Ah, those were the days! First or third angle projection, isometric views, whether or not to cross-hatch sectioned surfaces, all the fun of draughtsman humour (or not, depending on your point of view) etc. etc.

 

I did an Engineering Apprenticeship but didn't end up in a drawing office, however I did do a few designs and details here and there. Plastic film and leads were so much easier to use than paper and graphite.

 

CAD is fine and can do so much more but Engineers still need to learn to read three view drawings even if they can't produce them.....!

[TheSignalEngineer]

Hi,

 

I've just taken early retirement form an engineering drawing office for reasons such as the one you quote.  No one seems to care about standards anymore.

It's even got to the stage where 'you don't need to fully dimension a part, it's being made from the CAD file'.

 

But how do you know what has been produced by the machine is correct if the drawing isn't dimensioned?

[Dave47549]

.

[black5f]

 He drilled into us, by use of the high velocity board rubber,

 

Like that, I had one of those!

 

I think it's communication. Dims need to verify the production in clear terms, design office never had oily hands, in the shop or near a lathe (or near any metal in some cases). In my experience.

 

Sorry, added edit. Extra dims might be needed, I'm trying to be fair to our people. Our designers (I think) dream of high tech production processes when the shop is lathes and mills (but very skilled). So a 3D surface may also needs some profiles and extra dims, that type of thing, so the shape can be accurately communicated and then verified.

[Robert]

I’m currently “in discussion” with an Engineer who wouldn’t know what to do with a Rotring ink pen and an ultrasonic bath and he is adamant that there is nothing in the current standards that says you can’t throw dimensions wherever you want. Now obviously, a complex part with many dimensions may become over-cluttered and the draughter should use his common sense to produce a clear drawing; If this means putting a dimension between views, then so be it. But my feeling is that generally you should avoid this when possible.

 

I'm not a draughtsman, I'm an Engineer.

 

However, just because there is nothing in the standards doesn't automatically absolve an Engineer from common sense.

 

Many of the things that used to be called "standards" are now little more than recommendations and therefore open to interpretation, which is far from ideal.

 

While I agree that it is probably a certain amount down to communication I have, on a number of occasions, encountered attempts to do something daft, because the standards don't specifically say that you can't do it.

 

The Outsourcing thread also contains some good examples!

[Gruffalo]

Ah, the high velocity board rubber. I remember that one!

 

Technical drawing was the only subject that I both excelled with (I completed the 4th year work book before the end of my first year at school), & also enjoyed. I had a great & much respected teacher from my 2nd to 4th year, a Mr. French (who incidentally was a devout GWR fanatic). I wish I had pursued it, but I was losing interest as our new Teacher for the exam year couldn't spot enthusiasm if he tried - much less hit it with a rubber.  

 

Anyway, some 30+ years after leaving school & my last use of a T-square (guaranteed use of the board rubber for anyone seen to exclusively use one for drawing a horizontal line) in anger, I find myself out of work. I was recently sent on a skills course, the guy there advised I try for a job as a draughtsman. Some hope after all these years & no higher level accreditation!

 

>EDIT< I'm obviously not versed in standards, but rules A & B most definitely applied back then.

You've hit the head with the eraser on thar one Dave. It is always a positive learning experience when the tutor is enthusiastic about their subject and I was lucky to have such in school for metalwork, technical drawing and physics whilst at college I had such for mechanics, thermodynamics and naval architecture. I am grateful to them even now as without their enthusiasm, I would not have achieved what I did.

 

Now a question: I can draw solid objects in various projections but don't have the skill to draw in 3-d yet I need to convert my 2-d done in Dxf format to a 3-d image so it can be manufactured on a 3-d printer.

[bike2steam]

I still have my abridged version of the BS308 book from my apprenticeship days in the late 1960/early 1970's. But doesn't say about dimensions between views, but can remember being told - no.

[wirey33]

You've hit the head with the eraser on thar one Dave. It is always a positive learning experience when the tutor is enthusiastic about their subject and I was lucky to have such in school for metalwork, technical drawing and physics whilst at college I had such for mechanics, thermodynamics and naval architecture. I am grateful to them even now as without their enthusiasm, I would not have achieved what I did.

 

Now a question: I can draw solid objects in various projections but don't have the skill to draw in 3-d yet I need to convert my 2-d done in Dxf format to a 3-d image so it can be manufactured on a 3-d printer.

 

Which drawing package are you using ? If it's AutoCad I could probably help you out.

[DonB]

We occasionally had requests for spares for items or machinery originally made as far back as pre- WW1 where the drawings (transferred to micro-fiche!) were dimensioned but not given tolerances. The engineers back then were expected to use the work-shop's "standard practices", depending on whether a "free" or "interference" fit was required with a mating part.  I don't recall if there were dimensions in-between the views, but the penmanship on the drawings was immaculate and done without stencils, and any text was always in copper-plate style.

[jamie92208]

We occasionally had requests for spares for items or machinery originally made as far back as pre- WW1 where the drawings (transferred to micro-fiche!) were dimensioned but not given tolerances. The engineers back then were expected to use the work-shop's "standard practices", depending on whether a "free" or "interference" fit was required with a mating part.  I don't recall if there were dimensions in-between the views, but the penmanship on the drawings was immaculate and done without stencils, and any text was always in copper-plate style.

When I did my one year at Uni in 1971/2 on a Chemical Engineering course Technical drawing and Chemical |Process Principles were the only two exams, out of 11 that I mananged to pass (Beer and young ladies might have had something to do with this level of performance)  However I thorougly enjoyed the drawing and actually used some of the skills for modelling.  my efforts with pencil and paper were never neat but the basic principles have stood me in goods stead once I learned CAD from YouTube to do artwork for etches.   However I acquired some original drawings for Lancaster Green Ayre going back to 1889 nd they are absolutely beautiful things to look at and handle.

 

Jamie

[Jeff Smith]

General Arrangement drawings, which most of us would come across for modelling purposes only have overall dimensions with no tolerances. Assembly drawings may have dimensions with tolerances depending upon how the parts go together, I.e. a maximum and/or minimum length, diameter, etc. The individual parts making up the assembly, e.g. a complex welded assembly, would be fully dimensioned with individual tolerances or an overall tolerance quoted somewhere on the drawing.

I have never noticed dimensions between views - can someone explain this to me?

[rab]

But how do you know what has been produced by the machine is correct if the drawing isn't dimensioned?

That was always my argument.

The usual reply was as long as the features which mate with other parts are correct the rest doesn't matter!

[Jeff Smith]

That was always my argument.

The usual reply was as long as the features which mate with other parts are correct the rest doesn't matter!

! Certainly there are some products for which this may be acceptable but in high-tech products such as aerospace, weight, pressure vessel wall thickness and many other considerations make this generally unacceptable.

[gordon s]

One of the downsides of being a draughtsman in my early career is my total inability to do 'joined up writing'.  Several years of sitting at a draughting table and using block capitals on drawings means I lost the skill of handwriting and everything now is either typed or written in capitals.  Fun days back in the late 60's/early 70's that taught me a lot.  BS308 and first angle projection which then moved to third.  I still have my original set of drawing instruments that certainly get used from time to time.

 

Most impressive thing I ever saw was whilst on contract at BAC working on their proposed new aircraft, the 311.  Seeing guys working on lofting tables drawing aircraft wings and sections full size was something else and miles away from the electro mech design I was brought up on.

[br2975]

A-ha ! Memories of a former life - albeit my drafting was confined to highway design; including surveys and the subsequent setting out.

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My memories of 'Rotring' pens was the build up of ink on the nibs, and before drawing each line I'd draw the nib across my finger to remove any ink build-up - ending up zebra striped fingers.

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I had to learn to annotate plans in block capitals before I was allowed to use 'Uno' pens and stencils.

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Then there was puffing 'pounce' onto the negative sheet before starting to trace ................

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Almost 35yrs and a totally different career later, I still regularly use my set squares, French curves and other paraphenalia that stayed with me........ and, most importantly - the wooden footrest from under my drawing board still finds use for reaching across the layout.

.

Brian R

[Baby Deltic]

The thing is, even whilst I was doing my apprenticeship back in the 1980's, DNC was coming out. The draughtsman could run a tool path simulation from the CAD system and download the program directly into the CNC machine and run it, as long as the correct tools had been set in the machine, so the drawing didn't need to be printed off. First and third angle projection were the flavour of the day though, and threads had to be hatched to the inner dimension in cross sectional views.