DIY plywood book cradle (redux)
In the 2000s I was a volunteer for Distributed Proofreaders, an organisation that produces e-books for Project Gutenberg using a process that breaks up the work in manageable steps.
At the time I was looking into ways of creating a mobile scanning station that I could use to travel to libraries and rare book collections so that I could scan their books on location.
My idea was to create a so-called planetary scanner because in my experience it can be quite easy to damage books on a regular flatbed scanner – typically laying books open on a glass plate is bad for the spine, and when you turn over the book so that you can turn the page, you can easily rip a page.
Most of the parts of a planetary scanner can be bought off the shelf: tripods, cameras, glass plates, lights and so on. I could not find a book cradle however (little did I know that the ones for display purposes are called ‘book stands’) so I set out to make one myself.
Initially I made a cradle out of cardboard. That one functioned just fine, however after scanning a single book the cardboard walls had weakened to the point that they no longer could support a book.
So I made a second book cradle out of thin, soft plywood, and that is the one you can see here.
For the design, see this PDF.
I added a few components, namely a glass plate from a 3-euro picture frame and a printed reference sheet.
The glass plate is for keeping pages more or less flat.
If you keep the rest of the frame’s components, it will help you keep the glass plate undamaged during transport.
The reference sheet is just a print-out of a grid of squares and will help fix a few things beforehand or in post-processing: lens distortion (the lines should be straight), perspective (the squares should all be the same size), and white balance (the sheet should be white).
You might want to try and make the squares an exact size (for example 10 mm), but I never bothered with that, because getting it right is also a function of the printer you use. If you need to know the size of the book cover or the book’s pages, it is probably easier and faster to measure them by hand anyway.
I made the joints quite tight. Since I used fairly soft plywood this makes the cradle quite firm.
At this size, the cradle supports small and medium sized books. If you want to scan larger books, you have to get creative. (For example, you could make something that pushes the wooden sheets outwards.)
Once you are done scanning your book, everything combines into a strong and neat package that can easily be carried in for example a laptop bag.
I won’t go into the actual scanning process, because that could easily take up 3 or 4 more blogposts, but I have some notes from back in the day here.
As you can see (green dashed line added for emphasis), the glass plate can have quite a strong reflection. The angle of the light and the camera will play a role here.
Other people have made DIY book scanners with accompanying cradles, such as Daniel Reetz.
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