Beta Build

Built a scanner? Started to build a scanner? Record your progress here. Doesn't need to be a whole scanner - triggers and other parts are fine. Commercial scanners are fine too.

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daniel_reetz
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Re: Beta Build

Post by daniel_reetz »

cratylus wrote: Can anybody tell me what the virtues/vices are of the hinge vs. vertical/sliding vs. whatever else platen systems are? Why Dan, for instance, did you move away from your original hinged raising system?
Joel
The reason I moved from hinge to sliding in the "3rd gen" scanner was simply for space issues. Slides lay flat and take up little space; I couldn't make the hinge do the same in such a short time. Also, the hinged system would have bumped into my lighting setup because the front of the mechanism lifts so high (hinged setups need more headroom, in other words).

Personally, I still really like the hinged mechanism and I think it is appropriate for a wide range of builds. The only downside is really that the back edge of the "V" could potentially bite into a book as it comes down (but I never, ever had this problem even after scanning dozens of books). On scanners without toolbox liner or other non-slip material, there is a slight tendency to nudge the book toward the column side of the scanner. But again, I really think that the hinge design represents a dead-simple construction case and a good way to go for many scanner designs. Also, it's definitely cheaper than drawer slides.
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rob
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Re: Beta Build

Post by rob »

I am impressed! Just one thing about the parts list -- you specify a "spring set" from Home Depot. Just FYI, I've always had a difficult time finding springs at HD. You might want to specify what kind of springs they are, what length, what department you found them...

I think I like the slider solution better than the hinge solution -- for the reasons Dan mentioned, but also because I suspect that if we ever get around to working on a page turner, it will be much easier to move the platen that is on a slide than on a hinge.
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StevePoling
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Re: Beta Build

Post by StevePoling »

Dan, what's your feeling about using a hingellelogram attached directly to the platen? Not enough vertical range of motion? Or is the hingellelogram just to provide a floating platform for a 2nd hinge to which the platen is attached?
benjamin
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Re: Beta Build

Post by benjamin »

StevePoling wrote:I rather like the notion of a treadle-operated platen to keep both hands free to tweak the book position. I like it more than having a switch on the treadle fire the cameras when the platen reaches its down position.
I used a double pulley on our counterweight to leave room for this option. I played around with a bunch of different types of pedals and found that you had to extend pretty far out to get a sufficient range of motion without a gear mechanism. Started playing around with bike cranks and hubs but ran out of time on that side of the build. think the slick way to do this would be to find a motor that can be easily programmed to go a particular number of turns in either direction. my movie screen does this but i never really paid attention to how- there are two adjustable "limit screws."

i already scored a sweet dictaphone pedal that will hopefully someday provide this control system.
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daniel_reetz
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Re: Beta Build

Post by daniel_reetz »

StevePoling wrote:Dan, what's your feeling about using a hingellelogram attached directly to the platen? Not enough vertical range of motion? Or is the hingellelogram just to provide a floating platform for a 2nd hinge to which the platen is attached?
Not enough vertical displacement unless the hingallelogram is huge. I did experiment with huge ones cut on the laser, and they would work, with the caveat that the platen will move fore and aft somewhat with height.
cratylus
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Re: Beta Build

Post by cratylus »

I thought I had lost this pic, but I found it on a spare memory card. These are the MDF parts, post-paint. The work table is a remnant of my former life as a carpenter. It's awesome but you don't need one to cut the parts. In fact, I cut most of these in the snow, on my deck, propped up on cereal boxes and scraps.
DSC_0012.jpg
DSC_0012.jpg (282.78 KiB) Viewed 9270 times
I like the motor idea. I had in mind a rotating cog, kind of like the motion of an old locomotive wheel. I think that's how those old sewing machines worked. Maybe? I don't know. Maybe the motor could spin a captured threaded rod and the traveling portion would be forced to climb or descend according to which way the motor turned. I'm sure somebody(s) will come up with something.


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cratylus
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Re: Beta Build

Post by cratylus »

Not sure where to post this... here or book projects. Not sure about copyright issues either. But here's a post-processed, 4-page sample from a recently scanned book for those that are interested. Post-processing workflow consisted of Photoshop, Scantailor, FileRenamer and then a final crop in Adobe Acrobat. The text is slightly washed-out on one side of the page, so there's obviously room for improvement in the lighting department. Oh, and I'm shooting in JPEG.

Ultimately, my efforts will be spent archiving out-of-print building trades texts.
Sample2.pdf
(2.4 MiB) Downloaded 769 times

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Misty
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Re: Beta Build

Post by Misty »

Your results are very nice! What processing are you doing in Photoshop before sending it to Scan-Tailor? Is it the same actions you mentioned before, or something different since you're using Scan-Tailor now? I'd be interested in seeing a before-and-after set of shots with the JPEGs straight out of the camera. I saw that the EXIF on your sample on page one said it was a Nikon D90; is that what you were using to shoot that PDF?
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cratylus
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Re: Beta Build

Post by cratylus »

Misty wrote:I'd be interested in seeing a before-and-after set of shots with the JPEGs straight out of the camera.
Sure! Not the same book, but you get the idea. Unfortunately, I had to resize it due to the forum's allowable size limit.
209.jpg
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Basically, I sample a page from the beginning, middle and end of each session, and experiment with some combinations of exposure control, curves and levelings, and contrast. Once something looks like it'll work, I send the batch through. Then I go back and clean up any miscues. The photo below represents a quick attempt with +.25 Exposure and a Levels tweak in Photoshop. You can see that there's some room for improvement in the lower corners of the page. But again, I'm not looking for anything more than pretty basic B&W text. If I needed color or more "correct" contrast, I'd be lost. To that effect, I'm reading with interest the findings of your scanning project.
209b.jpg
209b.jpg (206.58 KiB) Viewed 9182 times
Misty wrote:I saw that the EXIF on your sample on page one said it was a Nikon D90; is that what you were using to shoot that PDF?
Yep. Right now I'm shooting with a fixed length Nikon 35 mm - F/1.8 lens. But that's only because it's what I've got. Don't ask me too many questions though, 'cause I'm a photography noob. ;)


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daniel_reetz
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Re: Beta Build

Post by daniel_reetz »

I have the manual version of that lens, and I love it.
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