Nalfonso's Simple Portable Scanner

Simple, Portable, Personal DIY book scanner

Postby nalfonso » 15 Sep 2009, 20:30

I have finally completed the first stage of my personal book scanner. Unfortunately I am not geeky enough, so I could not upload all the pictures I wanted to, but here is the address of a drop I've created, so interested parties can
view or download a 5 page PDF.

Anyway, I hope you can see at least two photos. I had a blast tinkering with this project, and after battling with many design concepts, the lesson learned is that simplicity is always best.

Attachments

Img_00 small.jpg
The fully assembled basic mechanical subsystem.

IMG_25.JPG
It all fits in a 5" deep briefcase!

Remarks

Postby you1 » 17 Sep 2009, 13:17
Excellent design.

During my experiments I found that raising the platen (with center side rails) was not "convenient". That is, the platen would want to lift one side before the other, get sticky, more force required to lift the platen, etc.
We can see some of these issues in Daniel's experiment http://vimeo.com/5723950

Which is why I moved my rails to the rear , and even added counter weight
http://www.diybookscanner.org/forum/viewtopic.php?f=1&t=74

Does your design not suffer the shortcomings that we've seen? If so, what do you think may contribute to it (i.e. size/weight)

-Edvin

Postby daniel_reetz » 21 Sep 2009, 14:45
Today, someone broke a piece of office furniture in our department, and as it turns out, it contained almost ideal drawer slides for our application.

The brand name of the cupboard this came from is Haworth. As you can see, it already has the hinges on it.

slide_1_09211328.jpg (365.89 KiB)

slide_2_09211331.jpg (384.35 KiB)

Postby smartechs » 23 Jul 2010, 12:12
Here is a drawer (actually pocket door)slide with a hinge built on it:

http://www.siquar.com/bs53.htm

smartechs

Questions and answers

Q: Postby fbonomi » 16 Sep 2009, 02:01
Impressive!
The briefcase makes it look like a James Bond-like device.

I am quite curious about the 120° angle, and its implications on the placement of the cameras (i.e, how to avoid reflections and "collisions" between the two cameras). I'll eagerly wait for your description of the remaining part.

fbonomi

Q: Postby you1 » 17 Sep 2009, 13:17
Excellent design.

During my experiments I found that raising the platen (with center side rails) was not "convenient". That is, the platen would want to lift one side before the other, get sticky, more force required to lift the platen, etc.
We can see some of these issues in Daniel's experiment http://vimeo.com/5723950

Which is why I moved my rails to the rear , and even added counter weight
http://www.diybookscanner.org/forum/viewtopic.php?f=1&t=74

Does your design not suffer the shortcomings that we've seen? If so, what do you think may contribute to it (i.e. size/weight)

-Edvin

you1

A: Postby nalfonso » 17 Sep 2009, 18:42
First of all, thanks for the congratulations, Daniel, fbonomi and you1. I am thankful to all who have contributed to this forum, your experiences encouraged me to try to build my scanner. Now that I have completed this stage I will concentrate on the remaining tasks.

Now, about the questions:

1. My answer to fbonomi: I chose 120 degrees angle for my platten after careful consideration of what type of books I would be scanning more frequently. The answer was: hardcover, relatively large (letter-sized pages and a bit smaller), textbooks and manuals. I thought 90 degress would be too small an angle for this type of material. Since I am planning on a single camera system, there is no chance for "collisions". Regarding reflections, I have obtained good results in cancelling them with the use of a polarizing filter. I own a Canon A540 Powershot and Conversion Lens Adapter LA-DC52F. This adapter has a 52mm thread that just happens to be the same size as the filters I have for my film camera. I have performed my tests using a tripod. We'll see how it goes once I complete the camera mount subsystem.

2. My answer to you1's questions: Yes, in my system the platten has a tendency to "roll" as you mention, but I must say that it is minor, not as much as I feared myself. I saw the video you cited, and I thought then that the long linkages Daniel used (about 10 cms on each side) increased the torque too much. In my design I used hinges as a simple solution to connect two angling planes, the face of the platten´s frame to the vertical slide. I think I will replace the hinges with solid aluminum brackets. That should take care of the small tendency to roll. And yes, I believe that the smaller size of my platten might also have to do with less roll or unevenness in the lifting. Curiously, I was afraid that the platten would lift first from the front and the rear would lag behind, but fortunately this does not happen, at least not noticeably. Here are the weights of the static and dynamic parts: The moving parts: the two glass plates combined, 1350 grams, the frame and joining plates and bolts, 500 grams, 50% of the combined weight of the two slides, 500 grams, for a total of 2,350 grams. The static parts: Board 1850 grams, craddle 950 grams and the other 50% of the slides, 500 grams, 2300 grams total. Thus, to counteract the force of lifting the platten, I have to clamp the board to the desk with two of those fast plier type plastic clamps!

nalfonso

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