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Drawing Help
https://rypn.org/forums/viewtopic.php?f=1&t=42937		 Page 1 of 1
Author:  10stewi [ Tue Jan 15, 2019 11:19 pm ]
Post subject:  Drawing Help
Bit of an annoying situation I'm currently dealing with. Does anyone have any software that can clean up the PDFs so more of the dimensions are readable? Ive already used the text identification and clean up feature in Adobe, but the results were minimal.

Back story on the drawings. We have these four photos because a member of our group visited the Hudswell and Clarke factory in the early 70's when they still were in business. There might have been more drawings for our locomotive extant at the time, but I have yet to turn up a drawing list.

Flash forward to today and the drawings are currently nowhere to be found! The National Railway Museum archives of Hudswell material have moved to the Statfold Barn Railway, but these drawings are not part of that collection. Other sources have come up dry or non-responsive.
Long and short of it, what ya see is what ya get, and we would like to improve the readability of the drawings.The locomotive came out of service for boiler repairs last year and will enter the shop next year for a full rebuild, inclusive of a new saddle tank to the dimensions in the drawing.

Anyone able to assist us? We appreciate any help we can get!

Attachments:
unspecified-7.jpg
unspecified-7.jpg [ 177.86 KiB | Viewed 7221 times ]
63.pdf [1015.72 KiB]
Downloaded 471 times
62.pdf [924 KiB]
Downloaded 432 times
61.pdf [1013.33 KiB]
Downloaded 443 times
60.pdf [1.33 MiB]
Downloaded 447 times
Author:  Dave [ Wed Jan 16, 2019 12:11 am ]
Post subject:  Re: Drawing Help
Copy the drawings in some reasonable scale, even if the numbers aren't legible. Then, measure the locomotive and write the numbers on the drawings. Using a scale rule, you can then interpolate very closely as to whatever data is still missing. What the designers thought should be built is less important doing a restoration than what was actually built - it's never perfect, but close enough if you're lucky.
Author:  Pegasuspinto [ Wed Jan 16, 2019 12:23 am ]
Post subject:  Re: Drawing Help
these seem to be REALLY SHRUNK DOWN PDF saves of a .tif file. Any chance that those files are still around? Once it's compacted there's no magic in the world that fills the missing pixels in.

Yea, these were shrunk down to the size of a large postage stamp. It takes over 700% zoom just to get it to fill my screen.
Author:  jayrod [ Wed Jan 16, 2019 9:31 am ]
Post subject:  Re: Drawing Help
The file properties provide that these PDFs were produced from TIF files of the same names and appear to be shot with a camera - the edges are rounded and the centers are sharper than the edges. These PDF's actual sizes are around 1" X 3/4". If they show as sharp as they do blown up from that size, the originals should be readable. See if you have those.

TIF files are uncompressed and should be very large in mb. If shot at 300 dpi, the files could each be around 24mb or larger.

There aren't enough pixels in these PDFs to work with. Hope these hints will help you find the original images. Otherwise, Dave's suggestion is also about the best that I can think of.
Author:  10stewi [ Mon Jan 21, 2019 11:29 am ]
Post subject:  Re: Drawing Help
Had a quick look at the size issue and found out why it happens. If using Adobe Acrobat, the files are cropped and fill the screen nicely. If just using photo viewer that can open .pdf files, it shows the original size I started with.

The original .tif files were most definitely not better unfortunately. Truly the sad shame of the original photograph quality. The current quality of the files is the result of post processing I attempted, which improved them to a very small degree.

Definitely going to have to measure and fill in the gaps where we can it seems.

Thanks for the suggestions everyone!
Author:  twofoot [ Mon Jan 21, 2019 3:20 pm ]
Post subject:  Re: Drawing Help
Stuart, if you know one dimension, you can fill in the gaps with anything else, especially in a CAD program.

I'm pretty sure the wheel dimension is a known quantity, work from that.

Good luck!

Chris
Author:  softwerkslex [ Mon Jan 21, 2019 7:00 pm ]
Post subject:  Re: Drawing Help
Of course, you could ask your dad, but I realize that there is that whole generation gap and all.
Author:  Ron Travis [ Tue Jan 22, 2019 1:33 pm ]
Post subject:  Re: Drawing Help
I don’t know of any easy way to recover the information in those drawings. The only way that a cad program could display the dimensions is if the drawings were in cad files that you could open in the proper cad program.

I think it would be possible to recreate the drawings, but it would be a lot of work. It would require starting over and producing the drawings in a new cad file. I would use a 2D program like Autocad or Draftsight, which is a free program. The process would be to re-draw the drawings using as reference, the drawings you have plus the actual locomotive.

You could start by drawing all features shown in the original drawings that have legible dimensions to define the features. Just plug the values of those legible dimensions into your new cad file drawing.

Then find the probable scale of the drawing by scaling dimensions that are legible and of the largest dimensional values. Also, to guide this discovery of the drawing scale, you can rely on the fact that the scale will likely be a round number expression such as one inch to the foot, for instance. So, it should be relatively easy to discover the actual drawing scale. Then use that scale to scale the drawing for dimensions that are illegible. Double check each scaled dimension by cross checking against as many related dimensions as available. This should result in discovering actual lost dimensions that are as near accurate as possible. Dimensions that are relatively independent and arbitrary will tend to be round numbers, so that can be a guide to the effort. Keep lots of legible notes on your process. You can also cross check by measuring parts on the actual locomotive.

I would lay the individual parts out rather than laying them out as an assembly drawing as shown in much of the original drawings. For the initial discovery of the dimensions, laying out the parts individually would be clearer than laying them out as assembled. Once you have them laid out individually, you can then copy and paste the layouts together to make the assembly drawings.

All of this would be a lot of work. The areas of critical fit would have to be evaluated and developed with tolerances just as if it were being done as a new design layout. The whole effort would be railway preservation in the sense of discovering and preserving the original design.
Author:  sleepermonster [ Wed Jan 23, 2019 11:47 am ]
Post subject:  Re: Drawing Help
Have you tried the Middleton Railway of Leeds, England? They have two similarly styled Hudswell Clarke 0-4-0st, one with 3'1" wheels and one with 3'4" wheels. They may be able to advise on either drawings or design features.
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