By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by Forum House Ad Zone

errors in drawings

All Topics | Latest Posts

Search for:  in Thread Title in  
1 2 Next > Last >>
Dave Jones 123/08/2009 17:52:49
85 forum posts
5 photos
would it be possible to create a section of the forum for people to list errors and omissions in drawings for ME articles and models.  I know of several websites and forums that have different ones listed, but it would make things a bit simpler if they were all listed in one place.
Dave
Circlip24/08/2009 14:05:14
1723 forum posts
It's a good idea Dave providing it doesn't turn into a witch hunt post showing how thick the original designer is, there's a difference between trying to sort a problem and some being downright bloody rude to try to score points. I suppose that's down to a Moderator thing, but why should they have to sully their hands when WE are supposed to be grown ups.
 
   Regards  Ian.
Richmond25/08/2009 08:34:10
avatar
73 forum posts
632 photos
64 articles
I have created a section called "Drawing errors / corrections" under the "Construction Articles" section of the forum.
 
You or we will be able to post questions regarding errors here, We will turn posts into "stickys" once errors are confirmed and solutions found.
 
Rgds
 
Dave Harris21/04/2010 20:18:53
28 forum posts
What might be a silly request....but!    When revised /new drawings are posted on this site for items in ME and or the 'Specials', could they be posted in a format that allows them to be printed on an A4 sheet, the ones for 'Lusus Naturae' will not print on one A4 sheet!?
David Clark 122/04/2010 11:14:13
avatar
3357 forum posts
112 photos
10 articles
Hi There
Save to computer and resize using a photo program or print and select fit to page.
regards david
 
Dave Harris22/04/2010 19:45:08
28 forum posts
Moderator, I do not understand what you mean by 'using a photo programme', and secondly my printer will not allow me to 'fit to page' for these drawings, they appear to be in a format the printer software cannot work with. Sorry to have to say this but my original request stands, please can you use use a format that everyone can access without having to get special programmes/software to deal with them?
Terryd22/04/2010 22:20:32
avatar
1946 forum posts
179 photos
I suppose that they could be created as a pdf file, but would that be too simple?  We could all print them out then easily. 
 
I'm not sure what you mean by a 'photo' program David .  Do you mean software such as Adobe Photoshop or Corel Paint Shop Pro?  As far as I know a 'photo' program processes just that  - 'photos' for simple printing.
 
Terry
David Clark 123/04/2010 07:45:05
avatar
3357 forum posts
112 photos
10 articles
Hi There
Anything that does jpeg as used for photos.
I use paintshop pro but you would probably have got something simple with your camera if you have one.
regards david
Terryd23/04/2010 16:43:11
avatar
1946 forum posts
179 photos
Ah, right, you mean a Graphics Program.  now I understand.
 
Thanks
 
Terry
Dave Harris23/04/2010 19:10:12
28 forum posts
Sorry but I dont understand, hence the original question, and from an earlier reply, ...if a pdf file is the type of file every computor system can deal with, why cant that be used for the benefit of all when putting drawings on this site?
Keith Long23/04/2010 19:39:28
883 forum posts
11 photos

Hi Dave

In order to read a pdf, you need to have an application like Adobe acrobat, or Foxit. A jpeg file is more versatile. You can even open the file and print it out using something like MS Word. In MS Word use the "Insert" command, then in the drop down menu select picture, from file (save the drawing to your desktop first). Then double click on the inserted picture and open the dialoge box to adjust size etc. Using just this route I've happily fitted both of the Lusus Naturae drawings on to the same page and printed them on A4 paper without going near a graphics program. It's worth having a look to see what you've already got installed on your machine and having a bit of a play.

Keith

Dave Harris23/04/2010 20:08:14
28 forum posts
Hi Keith,
 
            Many thanks for the explanation, the 'fog' is clearing! I will follow your directions later on and see how I get on.
 
Dave
mgj23/04/2010 20:27:08
1017 forum posts
14 photos
In Word you can annotate too quite easily. open, insert - text box. format that as through and you can write on a JPEG . Add arrows etc too.
 
So one easy way is to scan up as a JPG, add any annotations and post it as jpeg. 
 
To open a PDF file is easy if you have Reader.  But to convert to a PDF needs Writer unless other programs will do it. Writer costs ( a lot.)
Dennis R23/04/2010 22:30:33
76 forum posts
16 photos
      There is a free open source PDF creator at www.pdfforge.org/download haven't tried it myself yet, but have downloaded and installed it.
      Hope this helps
   Dennis
Keith Long23/04/2010 22:36:56
883 forum posts
11 photos

OpenOffice also lets you export documents as pdfs and is a free open source alternative to MS Office suite.

Keith

Terryd23/04/2010 22:38:04
avatar
1946 forum posts
179 photos
Posted by mgj on 23/04/2010 20:27:08:
So one easy way is to scan up as a JPG, add any annotations and post it as jpeg. 
 
To open a PDF file is easy if you have Reader.  But to convert to a PDF needs Writer unless other programs will do it. Writer costs ( a lot.)

 There are several points here which need addressing.  I would prefer engineering drawings etc, to be produced as vector graphics rather than as bitmaps, which jpegs are an example of.  The latter were developed to allow multicolour graphics such as photographs to be compressed to a relatively small size and not for monochrome diagrams.  If you enlarge or zoom into a jpeg it will 'pixellate' and eventually become intelligible,mall detail is lost.  Vector graphics have several advantages over jpegs, they are very much smaller files, and can be enlarged to any scale without loss of detail.  If you use the 'Drawing' function in Ms Word you are producing vector graphics.  Fireworks and The GIMP are examples of programs which will produce vector graphics and there are many very capable free graphics apps which will do the same..

 
BTW The GIMP is a top class graphics program and it's name is an abbreviation of The Gnu Image Manipulation Program and will handle just about all image formats (both Raster - which includes jpegs, png, bmp ets ans well as vector graphics),  Best of all it it is Open Source and Free!

 

Regarding pdf files, many word processors will 'print' to a pdf file.  Examples include the free Open Office suite of programs which will open all Microsoft documents.  Open office is a wonderful suite of programs (and if you add the free GIMP you have all the document manipulation and creation  programs you need.)
 
You can also download many free pdf creation programs and add ons for MS Word which will allow you to  create pdf documents from Word.  You certainly don't need Adobe Acrobat Pro to create simple pdf documents and just about every computer sold in the last 15 years has a copy of Acrobat reader and if not it is a small, free download.
 
Also .jpg and jpeg are one an the same thing, jpeg is not a graphics standard as such it is merely a 'lossy' compression format,  not really suitable for engineering drawings,(jpeg merely stands for Joint Photographs Expert Group).  See here:
 

Regards
 
Terry
Terryd23/04/2010 23:06:19
avatar
1946 forum posts
179 photos
I forgot to mention that CAD programs also produce vector graphics which explains why they can be enlarged greatly to inspect detail.
 
Here is a comparison of vector and bitmap images when enlarged.
 
 Great detail can be embedded in the simplest Vector graphis.  See here for a better explanation:
http://en.wikipedia.org/wiki/Vector_graphics
 

mgj23/04/2010 23:15:44
1017 forum posts
14 photos
Terry - there is always a saying " The best is the enemy of the good".
 
I also know what a JPEG is - it has limitations - for my photographic work i tend to use RAW and hten convert to 16bit TIFFS. however, if I want to do vector graphics,. I'll just open my copy of Photoshop CS3. If I want it big and without pixels  I can use vector graphics and my A3 printer. I'm sure you know the score. However an engineering drawing doesn't have much fine detail, being mostly black and white lines. But if you like, I can provide you with a 12megapixel photo that is almost A3 sized without interpolation and which will print to about A1 with the right interpolation software, and retain good photo detail. It will be a 150 megabyte file size which might take a little while to download - granted. With a macro lens that could be a pic of an original of something about 1" square. The point I am getting at is that you can make a JPG into whatever you like. It  doesn't have to be the 100kb sized web based photo which will pixellate at postcard size..
 
However - here we are talking of drawing ERRORS. You need a scan of the original and an overwrite of a dimension in most cases. The chances of needing to scan a patch of more than A4 size are not great.  (Just as well because most people don't have scanners that are over A4 size anyway and if A4 is the limit, there's not much point in worrying about pixellation under enlargement because that will be 1:1 anyway)
 
Also you have to provide these things in a format that most people can print off and use easily. If you don't  they won't pass the information on. 
 
With the greatest of respect, if you think I am going to be arsed to annotate a drawing, scan it, import it into Photoshop, convert it to vector graphics and then post it up on the internet - just so you can enlarge it so some fantastic size without it pixellating! I have better things to do, and you are overlooking the fact that there are many people out htere who may well have very valid observations on drawings,  but have not the faintest idea of what we are on about, or the interest ot find out, or the inclination to go trawling around to find programs that will convert to vector graphics, nor the desire to learn to use them when they have got them. And I certainly am not hopping about the internet to import programs which I am likely to use once every 2 years or so -  if that.
 
However, I'm quite happy to annotate (by hand if need be) and post a jpg which will print up actual size of the appropriate section of drawing, which is all one needs for this purpose.
 
We haven't by the way addressed the problem of checking the corrections. Or do we just accept that any submission is correct and machine accordingly? Which is a great deal more important than some vector based graphics diagram.
 
The best is always the enemy of the good.

Edited By mgj on 23/04/2010 23:19:23

Edited By mgj on 23/04/2010 23:24:20

mgj24/04/2010 09:27:37
1017 forum posts
14 photos
Terry - your argument about  pixellation is perhaps slightly awry.
 
If you enlarge enough bitmaps will break down, and if heavily compressed JPG will show the underlying 4x4 or 8x8 matrix with which the algorithm works. The answer is not - not to use jpgs, but simply not to compress them too much, and submit them in a pixel or megapixel size which is adequate for the purpose.
 
Vector graphics don't suffer from the matrix problem, but even so, wil pixelate in the end because they are composed of pixels.
 
However, sometimes, and it appears on that post above, there is a confusion between aliasing and pixellation. 
 
 Pixels are square because the hardware makes them square (they are actually simply mathematical points). So, like a brick wall, if you draw a horizontal line you can draw a pure edges line because the bricks all line up. Vertical likewise. But if you draw on a diagonal you have to go up in steps. Small steps but steps all the same. These jaggies are inevitable because we are viewing in pixels, and the effect is reduced by anti aliasing filters. However, at some degree of magnification the jaggies become visible.
 
If you want to use a bitmap and get rid of the pattern, just use a TIFF. You'll still get aliasing - and always will, so long as you use pixels.
 
There is also another problem with vector graphics - many uploading sytems won't accept graphic uploads by users other than in gif, png or jpg format. Nor above a certain file size, so you are back to compression and jaggies.
 

 

Terryd24/04/2010 13:00:02
avatar
1946 forum posts
179 photos
Hi mgj,
 
after 29 years in the computer graphics business (with 18 years web design experience) I understand all you say, I just didn't wish to get too technical for those who aren't necessarily so informed as ourselves. 
 
I'm very puzzled by you assertion that 'engineering drawings don't have much fine detail' in a previous incarnation as as a design draughtsman we were producing double A0 sheets with incredible detail.  I think that that we must differ on what is 'detail'.  A photograph may have lots of colour detail but this is not the point I am making.  when I wish to enlarge a drawing to view small detail, fine dimensions and notes I need good clarity which is not what one gets with bitmaps anti aliased or not.  I too can provide raw files from my 12.3 mpixel equipment, with macro or celestial telephotos, but this was NOT what I was discussing. (My 1.00 metre continuous printer will also produce excellent photographic images from my files.)
 
I can appreciate the use of tiff format as a container for bitmaps, however when used in this way, i.e. as a container for jpeg compressed files they are rather large (something like 3 times the size of the original jpeg - depending on the level of jpeg compression of course.  I agree also that tiff are useful for vectors using vector based clipping formats, However size once again, can be a problem.
 
True vector formats will enlarge by a ratio of hundreds and still retain clarity despite the small amount of pixellation, which is not possible with any bitmap, anti aliased or not and the files will be much smaller than bitmaps by a substantial factor.  most model engineers will have graphics programs which will handle vectors so reading vector files should not be a great problem for most.
 
As far as internet use is concerned I think you misunderstood my suggestion, perhaps I did not make my point with sufficient clarity,  I was not suggesting that vectors should be used for web based graphics as I know that jpegs etc are the accepted formats, but rather as the best format for storing files for complex engineering drawings which can be downloaded, stored, enlarged and studied in detail.
 
By the way I also think that digital photographs will never surpass the quality of good analogue ones as the regular geometric array of pixels can never truly compete with the random arrays of molecular silver halides, in the same way that digital music recordings will never have the quality of analogue whatever the sampling rate.  Just my opinion (and experience).
1 2 Next > Last >>

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!

Find Model Engineer & Model Engineers' Workshop

Sign up to our Newsletter

Sign up to our newsletter and get a free digital issue.

You can unsubscribe at anytime. View our privacy policy at www.mortons.co.uk/privacy

Latest Forum Posts
Support Our Partners
cowells
Sarik
MERIDIENNE EXHIBITIONS LTD
Shopping Partners
Subscription Offer

Latest "For Sale" Ads
Latest "Wanted" Ads
Get In Touch!

Do you want to contact the Model Engineer and Model Engineers' Workshop team?

You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.

Click THIS LINK for full contact details.

For subscription issues please see THIS LINK.

Digital Back Issues

Social Media online

'Like' us on Facebook
Follow us on Facebook

Follow us on Twitter
 Twitter Logo

Pin us on Pinterest

 

Donate

donate