Understanding Drawings
Understanding Drawings
(OP)
Hey,
I have diificulty reading drawings, my understanding is improving the more I look at them but I was wondering if anyone has any methods or tips that helped you when you started?
I have diificulty reading drawings, my understanding is improving the more I look at them but I was wondering if anyone has any methods or tips that helped you when you started?





RE: Understanding Drawings
What sort of drawings are you trying to understand?
desertfox
RE: Understanding Drawings
but help or tips on just general drawings would be greatly appriciated.
RE: Understanding Drawings
Here is a site that might help you:-
http://ww
You could always ask at college about books or go to the libary.
desertfox
RE: Understanding Drawings
Dan
www.eltronresearch.com
Dan's Blog
RE: Understanding Drawings
"Art without engineering is dreaming; Engineering without art is calculating."
Have you read FAQ731-376: Eng-Tips.com Forum Policies to make the best use of these Forums?
RE: Understanding Drawings
It seems that the capability of producing a good drawing is a lost art.
RE: Understanding Drawings
As you are concerned with valves,these are pretty simple have some old drawings and place them against the valve and start reading the drawing,slowly you will begin to understand the details. I too learnt the very hard way.
Learn the rules,so you know how to break them properly.
Dalai Lama
_____________________________________
RE: Understanding Drawings
Practice! Practice! Practice! Don't be too quick to jump to conclusions. Give the whole drawing a look before you start cutting. Start by getting the big picture (especially how views are related to one another) and work down to details.
Your efforts to learn will be hindered by drawings created by people who have less than a full clue about how to properly draft.
RE: Understanding Drawings
You may be reading poorly drawn drawings. Today's manufacturers have little time allocated for proper drawings: the old 'draw it and get it out the door as fast as you can' mentality of apparant cost effectiveness creates ripples of confusion all the way down the manufacturer/installtion/application lines. Expert draghtsmen (women) are becoming a rarity, especially those with board experience.
You may have a spatial block on your thinking: can you visualize in 3D? Can you move, change, rotate your visualizations? Most people cannot; every expert designer and drafter can. In this case you might research improving your spatial skills, visualiztion and such.
It could just be experience: you have not had enough exposure to drawings and their real world results. If you have access to a shop, assembly plant or supplier plant then walk around (if allowed) and look at what the assemblers, fabricators or workers are producing from what drawings (examine both).
Modern schools of engineering place little emphasis on drawings yet they are the fundamental link between the mind of the designer and the the real world result. Overcomplicating drawings with useless information creates too many questions and so, confusion. Too little information has the same effect. Experience is the teacher here. If you have access to many drawings then start studying the older designs and their parts in hand (if available) and you will see the cause-effect at work (or not).
Good luck.
RE: Understanding Drawings
follow the advice of all these good suggestions.
Is there some one helping you?
do not try this alone,
Ask for help if not sure what the drawing is requiring.
there is no shame in asking. there will be if you make a mistake.
Look a previous made parts & review it with drawings.
this will help. It is hard even for some season machinist or sheet metal guys to under stand what has to be accomplished. so they ask for assistance.
It will take lots of Instruction from more experience persons & lots of patients. do not rush since you are an
apprentice.
Take Blue print reading & drafting classes this will help.
Having a mentor will make your training & Job much easier.
Take Care
RE: Understanding Drawings
My ruled of thumb is that spoken communication is maybe 25% effective. (The listener hears and understands about ¼ of what the speaker meant.) Communication with drawings properly done to a standard convention may hit 90%.
Also, if you are in a project and someone objects when you ask questions, get out of the project as soon as you can.
Happy Thanksgiving,
tom
Thomas J. Walz
Carbide Processors, Inc.
www.carbideprocessors.com
Good engineering starts with a Grainger Catalog.
RE: Understanding Drawings
An old trick taught to me many years ago was to cut out or trace the views from the drawings and transfer them to some thin card and make a model with the aid of some masking tape or even model it up out of a piece of plasticine, you can always add bits on that way. It soon becomes second nature to "see" what is going on.
RE: Understanding Drawings
A simple learning tool you can make yourself, take a piece of 1" square bar stock cut it 2" long, cut one end off at 45 degrees, you will now have a piece 1"x 2" on one face, 1"x1" on the other and a sloping side on the other two faces. Paint every face and end a different color.
You can now use this to visualise different views as you would see them on a drawing.
B.E.
RE: Understanding Drawings
Taking a course in free hand sketching was one of my foundations in visualization. Spatial visualization is important to building engineering conceptions.
RE: Understanding Drawings
Just wanted to say thanks for all of the suggestions and im going to give as many of them as i can a go. Ive found this forum extreamly helpful and will hopefully be using it regularly.
Thanks again
Andrew
RE: Understanding Drawings
Project Engineer
http://www.cognidyn.com/
RE: Understanding Drawings
The reason is because the professors, mostly with little real world experience, expect draftsmen with a 2 year degree to be creating drawings from your designs. I was lucky enough to have people mentor me at my previous employers of the importance of a proper drawing. You learn quickly that red ink is your friend.
RE: Understanding Drawings
There are 'industry standards' for drawings. Now while not everyone (anyone?
They will lay out some of the fundamental rules/ideas behind projection of views etc, define common symbology and most other major drawing conventions.
So when I started, I asked lots of questions, I'd also spend time (much of it my own) looking at the drawing standards and one of my colleagues drafting books.
There are also some other forums on here that may be of more specific help such as:
forum1103: Drafting Standards, GD&T & Tolerance Analysis
forum281: Machines & Machining engineering
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Understanding Drawings
There are lots of dimensions on a drawing, except for the one You need.
RE: Understanding Drawings
Time too return to basics and the Professional Engineering Degree Program in the Universities instead of the simplified B.S. Programs.
RE: Understanding Drawings
"Cut these shafts" said the stuporvisor [sic]... "here's the drawing."
3" dia. steel about 18" long, to be turned down on the end to.... get this...
2.500" +/- 0.000"
I kid you not.
I laughed and laughed. The stuporvisor tried to insist that the drawing was correct, and to follow it. I tried to explain that machining to a tolerance of "zero" is not even possible, but if one were lucky enough to get one part to measure exactly on spec within 0.0005" then after removing it from the machine and cooling it, the dimension would differ to outside the "spec".
Good grief.
Examining the pile of parts left by the usual operator led me to the conclusion that the actual dimension was 2.500 +0/0.020" or so. Basically, to fit into the wheel bearing w/o too much slop, er, "clearance."
RE: Understanding Drawings
EVERY one of those little arrows and "notes" and letters and numbers and abbreviations on the piece of paper you are looking at has a meaning. The "intelligence" of the whole comes from how you integrate those details together (looking from the left side towards the right, looking from "above down" in one view and then loooking from the "right side" of THAT section view to "see" what is in the tird view of the assembly.
Also: the missing dimension is often on the manufactoring or prefab drawing, but is not repeated on the final assembly drawing you are looking at. A forged piece may get many of its dimensions from the orignal "casting" drawing, then the forged piece gets machined (with many hundred other dimensions), then parts get added to the machined piece on a third or fourth "level" of the drawing. So the actual dimension for length overall (LOA) may be on any of several earlier drwaings.
Also - notice that there always seems to be another "also" ?? - there are very specific rules for naming and displaying and plotting these projection views: but those "specific" rules for drawings are exactly OPPOSITE each other in Europe and in the US. This is NOT the metric/ANSI/inches/gage/pipe/steelshape/threads/sheetmetal/wire/plate/rebar measurement problem, but that European-drafted plots will be present the "opposite" side of the machine than what you are trained in if you started in the US. Alternate: they see our drawings and will produce "mirrir-image" parts because they have been properly trained in the opposite methods.
RE: Understanding Drawings
Do you mean the PROJECTION according to which a drawing is produced?? Any competent organisation will ensure that their standard drawing border will include the projection in words, with the standard 'conical frustum' icon or both.
And it's a mistake to think all those on the East of the Atlantic draw in the same way. We standardised on third angle more than 50+ years ago because it made more sense (and maybe something to do with WW2). Of course the Germans all seem to OBEY the DIN standards
RE: Understanding Drawings
RE: Understanding Drawings
RE: Understanding Drawings
RE: Understanding Drawings
There should be little or no guessing in drawing interpretation, if you don't know, ask. To assume ...
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Understanding Drawings
Prints made in 19xx
Company out of business
Author unknown
Popular Convention:
A - North to the left
B - North heads up
C - North follow flow direction
Sure it finally gets figured out, just a little time and some frustration.
Just a few days ago I realized I have interpreted the stock up and down in a completely reversed manner by looking the color of the number indicated in China website:
Red - DOWN (in US), UP (in China)
Green - UP (in US), DOWN (in China)
Glad I didn't throw any money in the trap.
Best practice - provide some consideration to readers...
Maybe I am asking too much, but that's the way I do.
RE: Understanding Drawings
Luckily, there are a lot of great tools to help an engineer or designer communicate exactly how parts should look and fit together available in ASME Y-14.5M-1994 (newer standards are available, but 1994 is quite widely referenced). It's 250 pages long and explains how to use Geometric Dimensioning and Tolerancing quite well.
Nonetheless, it may be a bit difficult to pick up off of the bat. If you'll be dealing with drawings extensively, you may consider taking an ASME class. ASME offers some good online classes that will get you up to speed on working with drawings. Good luck!
RE: Understanding Drawings
The modern Bachelor of Science engineering program is literally stretched to the limit. Most schools have reached the required credits limit allowed for a bachelors degree (I think it's 128 credits) and are now having to make very difficult decisions about what to cut back, or cut altogether. There is simply too much information to teach a normal high school graduate in 4 years, especially now that humanities (core class) requirements are increasing.
The decision to cut some of the drawing generation and interpretation classes is a pain, but at least it is something that can be picked up quickly with a little encouragement from an angry machinist!
RE: Understanding Drawings
"but at least it is something that can be picked up quickly with a little encouragement from an angry machinist"
Sadly not, or the drawings round here wouldn't have been so bad for so long.
Even in the UK where they don't have the same humanities requirement at least on my degree very little time was spend on design communication or whatever you want to call it.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Understanding Drawings
During which the Engineer, Machinist or Metal Fricator, is making a living.
Other countries have excelant such programs.
RE: Understanding Drawings
"Good to know you got shoes to wear when you find the floor." - Robert Hunter
RE: Understanding Drawings
"...and industry standards are usually specified. Projection method is also usually indicated, which should avoid problems like that mentioned by racookpe1978."
True, the lack of above in many otherwise excellent drawings is disappointing, it causes confusion and frustration. (A personal experience after few years dealing with mech drawings from different vendors/regions)
KENAT:
Sorry I didn't make it clear. I meant when you have to "guess" from those non-consistent country/regional/company conventions, it frustrates.
The other example has occurred a few times somewhere in the forum - one mistakenly interpretated the thickness left out by the other was in "mm" because "m" & "kg" were repeatly mentioned in the post. Wrong! It turned out to be "cm", a regional practice/standard of the poster.
I believe most of us here wouldn't make the same mistake. But "never"? Especially when we accross disciplines around the globe.