PDA

View Full Version : 2013 Can it be done?



Pontoon
2013-10-02, 08:32 AM
I dabbled with rasters a few years ago, and i'm aware i'm out of touch and technology will have moved on since I had access to raster design.
I have a friend who has asked if anyone can help restore this schematic for him. He can't get a good scan of it, but does have a picture.

The history behind it is quite interesting as it is a 1950's welder with this schematic on the inside panel.
http://i81.photobucket.com/albums/j201/bob_3103/20130929_152030.jpg (http://s81.photobucket.com/user/bob_3103/media/20130929_152030.jpg.html)

This is what he's said about it.
"
Took a chain block to unload it, modern tig welders with loads more features are the size of a suitcase http://www.scottishmini.net/forum/images/smilies/laugh.gif its badged as BOC but even they have no record, from what i have found on tinterweb it was made by P&H in america and rebadged over here by BOC before they even made there ADR welders. P&H stopped making welders in the late 50's
information is scarce hence wanting to preserve the schematic, dont get me wrong its not a heap its awesome! so old there are no electronic devices and can be mended with spanners and hammers, even the gas timers are mechanical, just a huge steel box filled with transformers http://www.scottishmini.net/forum/images/smilies/thumb.gif"

If it's possible can anyone give me any tips on how? If its not possible, it helps to know.

Ta

Opie
2013-10-02, 01:45 PM
Maybe Railrose can give you more advice on this. She is the resident expert, AFAIK. :)

dgorsman
2013-10-02, 04:32 PM
No way you can scan that, but a better picture would be necessary. From there, you can diddle with the contrast and gamma of the picture to bring out the linework. Some color filtering may help reduce the staining. From there, you can threshold (can't remember the Raster Design term for that) the image to bi-tonal (black and white), which will be enough to get a start with the linework.

By the time you do all of that, you can redraw from scratch with AutoCAD entities. After all, it is "just" and electrical schematic.

Pontoon
2013-10-04, 09:41 AM
No way you can scan that, but a better picture would be necessary. From there, you can diddle with the contrast and gamma of the picture to bring out the linework. Some color filtering may help reduce the staining. From there, you can threshold (can't remember the Raster Design term for that) the image to bi-tonal (black and white), which will be enough to get a start with the linework.

By the time you do all of that, you can redraw from scratch with AutoCAD entities. After all, it is "just" and electrical schematic.

Thanks for the response.
That's kinda what I was thinking.
It was the hope that the historic look of the drawing to could be kept. However I think he also would like the functionality of an easier read drawing. If I get the chance I'll redraw it for him.

I'll poke Railrose too :) Just in case she has some wizardry that may help.

I've heard of handheld scanners, and phones ability to work as a scanner, was intregued as to whether something like that would have helped.

Railrose
2013-10-08, 02:41 AM
Hi, Pontoon. What I've done in the past is make an envelope out of Mylar, then put bad drawings in it for scanning. Be careful of dust on the Mylar though, as it can scratch the glass as it moves through the scanner.

To make edits, you are best off to scan as a bitonal image. Basically, it means you have black pixels, or empty space. Then, edits are easy. If you scan as a photo, it sees the bits between the lines as white pixels, even if it's a black & white photo. If you scan as a photo, you can use it as an underlay to redraw it.

Another option is to print the photo in black & white, fill in missing line segments, then scan it.