Oversized Books, Oversized Kit?

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xeviousx
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Re: Oversized Books, Oversized Kit?

Post by xeviousx »

I have just bought one from diybookscanners.eu.

Some books i want to process are 21cm by 33cm and the scanners is just slightly too small.

Looking at the design, it looks like i would need to replace on 8 pieces (large L base piece, middle cross bar, camera supports, light supports) i would like to add 6cm in width front to back by extending only at rear.

Do you think this would be within the realms of possibility for sturdiness etc.

thanks
nittyjee
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Re: Oversized Books, Oversized Kit?

Post by nittyjee »

Do you think this would be within the realms of possibility for sturdiness etc.
I would think a slight 6cm change would not be a big deal, but I can't be sure. As Daniel said, the issue will be flexing, but I think that's more for the weight than the dimensions of the book. That is unless you're making the scanner much larger than you mentioned, and the weight of the cradle itself will be too much, but I would think that would take a lot. The best thing to do is to try it really. I would suggest just making one and trying it - I know it's a risk, but it's really the only way. You can't know until it's built.

One thing I realized was that it will help to have a design where the glass comes down rather than stays fixed. The "standard" design is suppose to be universal, so it can do tight paperbacks... though I'm unsure as to whether that even matters, because I've tested it and it works. If you did a scanner where the glass comes down, I would think that nothing would be an issue with flexing. I'll be posting on this in a moment.
nittyjee
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Re: Oversized Books, Oversized Kit?

Post by nittyjee »

Daniel - I'm not sure if I understand the logic behind the cradle coming up to the glass. You mention in the overview video that it allows it to be universal, so it can do paperbacks as well. But I just scanned a 400 page paperback book with the normal cradle lift method, and it worked fine. I also tested some tight small paperbacks, that don't stay open with their own weight, and it also worked fine. The glass catches the page, and it expands as you lift it up to the glass. I feel that if the glass came down, it would have fewer moving parts and there would be no issue with the weight of the book, the tension of the lifting mechanism, and so on.

Can you explain your reasoning behind this?
Thanks a lot.
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jbaiter
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Re: Oversized Books, Oversized Kit?

Post by jbaiter »

nittyjee wrote:Daniel - I'm not sure if I understand the logic behind the cradle coming up to the glass. You mention in the overview video that it allows it to be universal, so it can do paperbacks as well. But I just scanned a 400 page paperback book with the normal cradle lift method, and it worked fine. I also tested some tight small paperbacks, that don't stay open with their own weight, and it also worked fine. The glass catches the page, and it expands as you lift it up to the glass. I feel that if the glass came down, it would have fewer moving parts and there would be no issue with the weight of the book, the tension of the lifting mechanism, and so on.

Can you explain your reasoning behind this?
Thanks a lot.
I've only had problems when scanning paperbacks using the cradle. For one, the distance between the paper and the glass tends to vary depending on how far you're into the book, so I have to constantly adjust the position of the spine. No such problem in paperback mode, where I just press the book against the glass. Second, using the cradle, I often can't shoot the whole text when the margins are very narrow and the text close to the spine. Again, paperback mode allows me to apply more pressure to the spine, exposing more of the paper to the cameras.
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daniel_reetz
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Re: Oversized Books, Oversized Kit?

Post by daniel_reetz »

jbaiter wrote:
nittyjee wrote:Daniel - I'm not sure if I understand the logic behind the cradle coming up to the glass. You mention in the overview video that it allows it to be universal, so it can do paperbacks as well. But I just scanned a 400 page paperback book with the normal cradle lift method, and it worked fine. I also tested some tight small paperbacks, that don't stay open with their own weight, and it also worked fine. The glass catches the page, and it expands as you lift it up to the glass. I feel that if the glass came down, it would have fewer moving parts and there would be no issue with the weight of the book, the tension of the lifting mechanism, and so on.

Can you explain your reasoning behind this?
Thanks a lot.
I've only had problems when scanning paperbacks using the cradle. For one, the distance between the paper and the glass tends to vary depending on how far you're into the book, so I have to constantly adjust the position of the spine. No such problem in paperback mode, where I just press the book against the glass. Second, using the cradle, I often can't shoot the whole text when the margins are very narrow and the text close to the spine. Again, paperback mode allows me to apply more pressure to the spine, exposing more of the paper to the cameras.
Everything jbaiter said, and then one more thing, and I believe this is absolutely critical. My goal is to make these scanners as turn-key as possible, meaning that there is basically no user adjustment necessary.

Fixing the distance between the platen glass and the cameras solves that problem neatly. Otherwise, when the platen moves, the page center in the camera frustum is dependent on the thickness of the book. Also, we wouldn't have paperback mode. It's still an experimental feature, but one I want to explore more fully in the future.
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