Not exactly a build yet, but a start on one.

[TomHorsley]

I'll be updating my web site as I make progress, but figured I should post a pointer to it here:

http://home.comcast.net/~tomhorsley/har ... anner.html

Canon shipped my cameras from Wisconsin, and the appear to be frozen in place right now, so I don't know when I'll be able to test them .

[Anonymous1]

I envy your three-button mouse I ripped apart a scroll mouse, and it's extremely useful for triggering. Right click for focus, left for trigger, and flip the crudely-inserted sliding switch for long exposure.

if you are running Linux, you can actually get live previews of your cameras via the USB cables. You can even trigger them through the cables also. I have only a single DSLR, so I don't know how well it can work with two point-and-shoot cameras (don't worry, it works. This is just an ancient screenshot): http://www.gphoto.org/proj/gtkam/

Good luck!

[TomHorsley]

I've updated my web page to show more progress: The base is finished now, and all parts for the platform are cut, but need assembly. May be a few days before I get back to it.

I've also been thinking about the platen, and I'm liking the idea of a hinge rather than a sliding lift. I've also considered making it bi-stable with a counterweight on a lever that hangs in back of the hinge pivot to keep it raised, and in front of the hinge pivot to keep it down, but I don't know if there is any point to doing that. Folks who have scanned a few books: Would it be convenient to have a platen that stays up when you let it go after raising it and also stays down when you let it go after lowering it?

Meanwhile, my cameras are apparently still frozen in Wisconsin, no progress reported by FedEx yet.

[daniel_reetz]

There are a couple of pivoting or hinged platens on here but I'd really love to see more from builders such as yourself! Especially on the "new standard" designs - there is a need for a simplified platen movement mechanism.

Here are a couple of links that may inspire:
http://www.diybookscanner.org/forum/vie ... 76&start=0
(I really love Spamsickle's approach http://www.diybookscanner.org/forum/vie ... t=10#p4213)
http://www.diybookscanner.org/forum/vie ... ?f=1&t=761

On my old scanners I really liked the mechanism to have a little bit of a downward bias so it would hold the book in place, but it's been a while since I thought that was necessary. There were definitely times in my book scanning life when I wished that I had a Rob-style platen that would swing up and stay up indefinitely while I fixed something in the book or inserted a new book or whatever.

[TomHorsley]

Now you've got me thinking about a parallelogram mechanism, which might need a lot of clearance and get in the way of the cameras, but then I'm thinking the cameras might be mounted on the platen. Clearly something to mock up with cardboard and sticks before attempting for real .

[TomHorsley]

As much fun as the parallelogram would be, I was able to resist actually trying it. I'm just going to go with a simple hinge. I've finished my replica of the standard scanner base and platform, and I've added a picture with my platen mock-up to my web page:

http://home.comcast.net/~tomhorsley/har ... tml#Platen

[spamsickle]

I would worry about a couple of things in the design as posted on your website.

First, that bar that crosses over the middle of the platen is likely to block lights, camera, or both. Even if you're planning to put LEDs in the bar itself, I expect the bar would block the view of part of the book, if you're shooting books of any size at all.

Second, the platen may not contact the book properly. Both Rob's design and mine suspend the platen so it can swing freely and "tilt" to accommodate different book thicknesses. If the platen is just levering in, it will contact the edge of the book closest to you and be too high at the edge of the book furthest from you, or vice versa. Either way, it's probably not going to be what you want -- something that holds both pages fairly flat, so the cameras can photograph them that way.

[TomHorsley]

First, that bar that crosses over the middle of the platen is likely to block lights, camera, or both. Even if you're planning to put LEDs in the bar itself, I expect the bar would block the view of part of the book, if you're shooting books of any size at all.

That's just there to reinforce the foam board prototype and isn't intended to be part of the final build .

Second, the platen may not contact the book properly. Bot Rob's design and mine suspend the platen so it can swing freely and "tilt" to accommodate different book thicknesses. If the platen is just levering in, it will contact the edge of the book closest to you and be too high at the edge of the book furthest from you, or vice versa. Either way, it's probably not going to be what you want -- something that holds both pages fairly flat, so the cameras can photograph them that way.

I have hopes that a lose enough hinge adjusted to the right height so it is almost level as it makes contact will help, but that is indeed a thing to worry about, but I also wonder about the free swinging design. Can't it wind up rocking as you lower it and either slow you down or have similar problems hitting one side first?

[spamsickle]

I have hopes that a lose enough hinge adjusted to the right height so it is almost level as it makes contact will help, but that is indeed a thing to worry about, but I also wonder about the free swinging design. Can't it wind up rocking as you lower it and either slow you down or have similar problems hitting one side first?

I'm holding the platen on both sides as I lower it, so in theory I can keep that from happening. Most of the time, I keep it from happening in practice too, but sometimes it will hit one side first. With me, when that happens, most often it just slides down into place. Occasionally when it slides, the book will slide with it (I should be using that non-skid foam that Daniel recommends, but I'm not). I'm planning to take steps to keep the book from moving at some point; for now, I just keep an eye on it, make sure it stays in frame, and let the software (Scan Tailor or Book Scan Wizard or even JpegCrops) handle it in post.

There was some early discussion of something called a "hingellelogram" which may be useful in your design. I never tried it myself, so I can't comment, but do a search and see whether it gives you any ideas.

[TomHorsley]

I'm holding the platen on both sides as I lower it, so in theory I can keep that from happening. Most of the time, I keep it from happening in practice too, but sometimes it will hit one side first. With me, when that happens, most often it just slides down into place. Occasionally when it slides, the book will slide with it (I should be using that non-skid foam that Daniel recommends, but I'm not). I'm planning to take steps to keep the book from moving at some point; for now, I just keep an eye on it, make sure it stays in frame, and let the software (Scan Tailor or Book Scan Wizard or even JpegCrops) handle it in post.

Good to know. Maybe my design wouldn't be hard to adapt to a free swinging scheme. I could just put a couple of pins in the middle of each side of the platen, and let it swing by those rather than firmly fixing it to my hinge mechanism. Perhaps with a small knob attached to the front I could use to control any swinging when lowering it.

P.S. They sell rolls of non-skid stuff in my supermarket. I use it almost everywhere (like under the feet of all my electronics). It really is amazing. I had already planned to stick some under the books as a way to keep them in place.