Daniel Reetz, the founder of the DIY Book Scanner community, has recently started making videos of prototyping and shop tips. If you are tinkering with a book scanner (or any other project) in your home shop, these tips will come in handy. https://www.youtube.com/channel/UCn0gq8 ... g_8K1nfInQ

Thumb Thing

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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StevePoling
Posts: 290
Joined: 20 Jun 2009, 12:19
E-book readers owned: SONY PRS-505, Kindle DX
Number of books owned: 9999
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Thumb Thing

Post by StevePoling » 07 Jan 2010, 00:45

Dan brought to my attention a gizmo called a thumb thing. It fits over your thumb and holds a book open. He thought it might be helpful when operating in a platenless fashion. I put some thought into it and finally came up with something I could run some tests against.

Imagine a bit of cardboard and make an 8" right triangle with a notch taken out of the right angle. And I used a bit of black duct tape to hold the dowel to the thingy. It looks like this:
Image
Here's another angle:
Image

I don't think this is the final word on thumb things. I've got in mind replacing the cardboard with some sweet birch plywood and changing its shape from triangular to a swept wing shape. And replacing the black duct tape with a piece of bicycle inner tube.

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daniel_reetz
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E-book readers owned: Used to have a PRS-500
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Re: Thumb Thing

Post by daniel_reetz » 07 Jan 2010, 08:56

So intriguing! Have you tried any page-turning operations with it?

I think this is key to a lot of ideas I've been having... I might follow along with you building a similar device. Great work, Steve!

PS. Noticed on your Flickr account that you were wondering about coloring the edges black or not. I think black is the right way to go because it won't miscolor anything by reflection. However, if you want to put fiducial marks on the image edges to make processing easier, perhaps fluorescent string or thin strips of fluorescent green tape would give enough of an indicator without causing too much odd reflection.

Green is the right choice for fiducial marks for two reasons. One, cameras are most sensitive to light at ~530nm. Second, because the Bayer CFA typically has twice the green elements as it does R and B elements, the green channel of any DSC image usually has the most resolving power.

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daniel_reetz
Posts: 2786
Joined: 03 Jun 2009, 13:56
E-book readers owned: Used to have a PRS-500
Number of books owned: 600
Country: United States
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Re: Thumb Thing

Post by daniel_reetz » 07 Jan 2010, 08:58


StevePoling
Posts: 290
Joined: 20 Jun 2009, 12:19
E-book readers owned: SONY PRS-505, Kindle DX
Number of books owned: 9999
Location: Grand Rapids, MI
Contact:

Re: Thumb Thing

Post by StevePoling » 09 Jan 2010, 15:49

daniel_reetz wrote:So intriguing! Have you tried any page-turning operations with it?

I think this is key to a lot of ideas I've been having... I might follow along with you building a similar device. Great work, Steve!
I just tried going a dozen page turns. The operation was not as simple as I imagine platen operation to be.

Because of dowel is loose on the rear thumb thing, it wants to flop around a bit. Thus, each page turn requires me to set the left and right edges of the rear thumb thing onto the page. The front thumb thing is less floppy. Nevertheless, I verify that both front and rear thumb things haven't flopped into the text nor off the page.

I should replace my son's 2.5lb weight with a lead-weighted handle.

Here's a nice snap of my index finger.
Image

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