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Quote:Original post by owl Anyway, a sheet feed scanner should allow you to scan long sheets. You could cut/fold your drawing in half or disasasembly the scanner and find a way to scan the big sheet from the left and then from the right.
That approach requires him to stitch together the distinct scanned images, which is what he was trying to avoid in the first place.
Quote:Original post by owl Anyway, a sheet feed scanner should allow you to scan long sheets. You could cut/fold your drawing in half or disasasembly the scanner and find a way to scan the big sheet from the left and then from the right.
That approach requires him to stitch together the distinct scanned images, which is what he was trying to avoid in the first place.
I'm just throwing some more ideas, maybe he can come up with something better himself. I think it'd be really hard to be able to build a 12"x18" scanner with a 9" sensor.
The only other realistic thing I can think of is replacing the glass from the scanner by a 12x18 one mounted in such a way that it can be precisely moved left-right/top-bottom. Then, write a routine with Twain that scans the sheets as many times as required to get the full page and performs the cropping/glueing of the image in software. Yet getting the glass to move precisely enough (by hand) is gonna be an issue.
Quote:Original post by owl I'm just throwing some more ideas, maybe he can come up with something better himself. I think it'd be really hard to be able to build a 12"x18" scanner with a 9" sensor.
I don't think he's trying to build a flat bed scanner at all, given his space constraints. I believe he's trying to build a continuous-feed scanner like this one, albeit a little smaller. The linked scanner can accept materials up to 42"x100' - yes, one hundred feet.
Well, the way most flatbed scanners work is they have a fairly small optical sensor that can move back and forth on a small track. This track reads 'across' the page, and after reading a 'line' it is advanced to the next line.
Basically the project is to build a long track that can take a 1-2m wide 'track', and rather than moving the track, a large traction wheel system will pull the page itself forward.
I have a lot of old plans and large format documents that I can't cut up to scan, and a handful are of buildings that are considered 'secure', and therefore I can't just send the plans out to a company that could scan them for me.
Old Username: Talroth
If your signature on a web forum takes up more space than your average post, then you are doing things wrong.
Quote:Original post by owl But God save me from having to write a driver for such a thing.
In your setup, you don't have to. Just write a TWAIN capture program, which captures from both in parallel, and then stitches in software.
There is the issue with the feeding wheels. I'm thinking of two separate scanner controlers.
What issue is there with the feeding wheels? It will be a main full width drum likely 6 to 12 inches in diameter (15 to 30cm) that is covered in a soft rubber material that provides good grip on paper. Then on either side of where the scanner head moves back and forth there will be a secondary drum that holds the paper against the main traction drum head.
Scanner head moves across the width of the traction drum, drums advance 1/2 width of the scanner head, scanner head moves back to starting location, drums advance 1/2 width of scanner head again, repeat as needed to reach end of page.
Old Username: Talroth
If your signature on a web forum takes up more space than your average post, then you are doing things wrong.
