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

ac powerd hub, bike brakes

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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JRebollar
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Joined: 04 Mar 2014, 00:52

ac powerd hub, bike brakes

Post by JRebollar » 28 Jan 2010, 12:30

i have an idea for a book scanner i am making blue prints for i want to know from an experience hand the possible cons and pros for my idea.

i was thinking using a ac powered hub for the cameras or just connecting the cameras to theirs ac adapters.

what would be bad about using the flash of the cameras?

would their be a con in using two bike brakes one on each camera adapted to one handle brake instead of using said software?

JRebollar
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Joined: 04 Mar 2014, 00:52

Re: ac powerd hub, bike brakes

Post by JRebollar » 28 Jan 2010, 12:49

http://cgi.ebay.com/SST-ORYG-Gyro-Brake ... 937wt_1165
i am sure any one can find this in a junkyard of a bmx bike.
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Misty
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Re: ac powerd hub, bike brakes

Post by Misty » 28 Jan 2010, 12:50

Flash tends to produce uneven illumination for book-scanning, so you'll have a bright spot on part of the page. That causes problems for OCR software and Scan Tailor, and makes it harder to get good results.

Here's a sample image using flash. It's not a perfect example (I was just holding the book, it wasn't in a scanner - my cradle's disassembled), but it gives an idea of what happens.
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The opinions expressed in this post are my own and do not necessarily represent those of the Canadian Museum for Human Rights.

DDavid

Re: ac powerd hub, bike brakes

Post by DDavid » 28 Jan 2010, 13:46

I often use the flash on my cameras to copy pages not whole books.
I have a piece of tissue paper taped over the flash to diffuse and
lower the amount of light to get a usable result. The result and the
glare issue is not that good, just usable for my purpose. Usually I'm
just coping a few paragraphs I want to OCR and cite.
The main issue I can think of is that it may slow you down even
with AC power for the capacitors to recharge enough to fire the flash.
That may not be an issue since you've stated most of your work
will be flat items and you will not be working as fast as you would be
on a book.

spamsickle
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Re: ac powerd hub, bike brakes

Post by spamsickle » 28 Jan 2010, 14:31

I'd think glare would be a problem if you're using a flash attached to the camera and a glass or plastic platen to hold the page flat. Even without a platen, I've had glare problems shooting magazines with glossy pages.

If you have a flash that's not attached to the camera, you can probably arrange things to avoid problems with glare. Uneven lighting may still be a problem, as Misty mentions, but as long as it's not too severe the post-processing software (Scan Tailor) can probably handle it.

JRebollar
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Joined: 04 Mar 2014, 00:52

Re: ac powerd hub, bike brakes

Post by JRebollar » 28 Jan 2010, 14:55

ok i got it flash is not a very good idea. what about the other things i mentioned?

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daniel_reetz
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Re: ac powerd hub, bike brakes

Post by daniel_reetz » 28 Jan 2010, 15:00

A lot of people have experimented with AC adapters.

No one has made a bike brake system yet, we've only talked about it. Be the first and tell us what the cons are.

spamsickle
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Joined: 06 Jun 2009, 23:57

Re: ac powerd hub, bike brakes

Post by spamsickle » 28 Jan 2010, 21:18

My system is all AC, thanks to Dan's AC dual-USB trigger. I don't like depending on batteries if there's any way at all to avoid it. I don't know about an AC hub, unless you're talking about a power strip, but plugging my cameras into a power strip using their AC adapters is working fine for me.

One potential disadvantage I can see with using a bike brake system rather than the CHDK software is that the bike brake can only control the shutter. I'm using the software to set exposure and focus too, so I don't have to worry about them. If you're sure you'll never want the software to do more than trip the shutter, a bike brake system may suffice. In that case, the only design problem I can foresee is getting the mechanical registration and pressure to be reliable shot after shot.

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