Monson's Servo Auto Scanner

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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rob
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Re: Monson's Servo Auto Scanner

Post by rob »

Wow, that is some serious awesome. What happens if you try it with the same book on the first few and last few pages?
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jck57
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Re: Monson's Servo Auto Scanner

Post by jck57 »

dtic wrote:This is amazing, amazing work! It is a pleasure to just watch the video and see page after page turned. :) I saw your PM just now but you clearly have arduino working great already. Very smart solution with different timings for the upper/lower pageholders. There's also only 4 servos in total (from what I see).
Thanks. Still don't know how to get servos to run at overlapping times. Any help would be good. This code is just "sweep" sequenced for each servo.

4 servos, yes. You may remember I thought 7. Fewer is more better.
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jck57
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Re: Monson's Servo Auto Scanner

Post by jck57 »

rob wrote:Wow, that is some serious awesome. What happens if you try it with the same book on the first few and last few pages?
The last two or three pages are hard to pick. They want to all slide together. Not sure why.
dtic
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Re: Monson's Servo Auto Scanner

Post by dtic »

jck57 wrote: Thanks. Still don't know how to get servos to run at overlapping times. Any help would be good. This code is just "sweep" sequenced for each servo.
If I understand you right you want to move two or more servos simultaneously. This code from my sketch does that. It first sets the variable "val" to 50 and then decreases that value by 1 on each loop until the variable reaches 19. Each loop writes the current value of val to servo1 and val+110 to servo2. That tells the servos to move to those positions from their previous positions (so they move one step on each loop). The "delay(10)" part controls the speed. Increase that number to slow down. What start value and loop range to use depends on your servos positioning and range; I got the values I used through trial and error.

Code: Select all

for(int val = 50; val>=19; val--)
{ 
  servo2.write(val + 110); 
  servo1.write(val); 
   delay(10);
}
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jck57
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Re: Monson's Servo Auto Scanner

Post by jck57 »

dtic wrote:
jck57 wrote: Thanks. Still don't know how to get servos to run at overlapping times. Any help would be good. This code is just "sweep" sequenced for each servo.
If I understand you right you want to move two or more servos simultaneously. This code from my sketch does that. It first sets the variable "val" to 50 and then decreases that value by 1 on each loop until the variable reaches 19. Each loop writes the current value of val to servo1 and val+110 to servo2. That tells the servos to move to those positions from their previous positions (so they move one step on each loop). The "delay(10)" part controls the speed. Increase that number to slow down. What start value and loop range to use depends on your servos positioning and range; I got the values I used through trial and error.
OK, now I get it. Thanks.
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daniel_reetz
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Re: Monson's Servo Auto Scanner

Post by daniel_reetz »

FYI: The page turner work from the forum is now on Hack A Day! Congrats, all!

http://hackaday.com/2011/10/02/page-tur ... r-roundup/
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rob
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Re: Monson's Servo Auto Scanner

Post by rob »

jck57 wrote:The last two or three pages are hard to pick. They want to all slide together. Not sure why.
Hmm. My guess is that there is a force exerted on the pages by the spine which tends to turn the pages. For paperbacks, the force is so great that the book closes if you don't hold it down. The fewer pages there are on one side, the greater that force is. You can probably see this effect just by setting a textbook down on a table, turning to the final pages, and seeing that the pages sort of stand up in the air -- if the book doesn't completely close on you.

I did this experiment, and observed how my fingers were arranged as they turned the page, and so the key here may be to use two fingers on the lower right. One finger (the "thumb") presses down on the page at the center of the bottom. The other finger (the middle finger, in my case) presses down on the page at the lower right corner, and then slides towards the thumb, lifting up as well. And while we're adding fingers, a third finger then slips under the page corner after it has been lifted, which enables turning the page.

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jck57
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Re: Monson's Servo Auto Scanner

Post by jck57 »

Re: jck57's Automatic Scanner Build
by pfarber » 02 Aug 2011, 21:52
I would consider using rubber wheels/rollers on the very edge of the page. I work on printers all day and you would be amazed at what a rubber roller and the proper amount of spring pressure will accomplish.
I pasted this post from my old pneumatic full auto scanner thread. If pfarber or anyone else with ideas is reading this: Given a rubber wheel diameter of 1 3/4", how wide should the wheel be? I want the wheel to contact the paper near the corner, similar to what I'm doing now with the rubber tipped pusher. Also, what rubber material is best and where could i find such a wheel or tire material for the wheel? I'm thinking about attaching to the servo arm another servo with a rubber wheel in order to improve reliability of lifting single pages. The rubber tipped lifter is finicky with different types of paper. What I'm after is the stickiest rubber attacking the page at the lowest possible angle with minimum downpressure on the paper.
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Re: Monson's Servo Auto Scanner

Post by snaguy »

He is referring to a feed roller. These are plentiful on eBay.

I recommend a small air compressor to blow into the spine before the page turning process.

When running a production laser printer and getting double sheet feeds we will fan the paper to prevent this problem. The paper tray has air blowing into the side of the paper to help separate the sheets and then elevate the paper onto the feed rollers which will push the sheet through the paper path.

With a bound book it is not as easy to fan the pages. Some books may have been squashed on the shelf.

And I must say very nice work.
aeturneus
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Re: Monson's Servo Auto Scanner

Post by aeturneus »

Very excited about this method. I know that to help with separation of pages you can just get some air between the pages by flipping through them before putting them in a printer - would that help with this scanning method at all?

I like the idea of a feed roller, or two feed rollers, to separate the top page instead of a finger, but it seems to me the trick would be getting the weight right - too light and the feed roller won't move anything, and too heavy and the feed roller will grab more than one page. How would you set the weight of the arm that brings the feed roller down onto the page?
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