Lego Mindstorms scanner - A novel way of scanning magazines

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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cday
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Re: Lego Mindstorms scanner - A novel way of scanning magazines

Post by cday »

Yes, very original and very impressive results, 'he who dares wins'! :D

Presumably you are imaging one page at a time, are you currently applying any corrections for non-perfect flatness of the pages, whether using the Czur software or another method?

Those pages in the video do lie surprisingly flat, is that maintained further into the magazines? Still wondering if a downward air blast might possibly be beneficial.
JasonStonier
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Re: Lego Mindstorms scanner - A novel way of scanning magazines

Post by JasonStonier »

The pages lie pretty flat all the way through - the rollers do a good job of putting micro creases into the 'spine' as they go over.

It captures both pages as an A3 then I spilt them using nconvert in a batch process later. There is a bit of warping towards the back of the magazine, but as I'm capturing the images raw, I'll look to see if I can do any post-processing on the left page to reduce that. At the moment, though, I''m fresh out of patience from Mrs S for any more tinkering in the evening ;)
cday
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Joined: 19 Mar 2013, 14:55
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Country: UK

Re: Lego Mindstorms scanner - A novel way of scanning magazines

Post by cday »

Your system is very impressive as a 'proof of concept' if I may term it that, as far as I know entirely novel and serving your immediate need well. :D

I have been thinking, though, about whether a belt drive might alternately be used? My original thought was that a belt drive could substantially speed up operation, realising that full automation is much more important than scanning speed. A further thought concerns the expected life of the parts currently used, where a belt drive might be more durable?
JasonStonier
Posts: 19
Joined: 16 Nov 2021, 06:29
E-book readers owned: Kindle Paperwhite
Number of books owned: 2000
Country: UK

Re: Lego Mindstorms scanner - A novel way of scanning magazines

Post by JasonStonier »

It is a belt drive actually - probably not obvious from the video - there are two lateral GT2 3D printer belts that run down the sides to move the carriage. My original concept was to use the rack-and-pinon but I found I couldn't get the carriage stiff enough - but by that point I just keep them in as runners anyway. I designed and 3D printed lego-compatible GT2 timing pulleys to fit the belt.

The problem with getting it faster is that the page tends to get folded if I push the speed up - it relies on the paper being able to bounce and settle into a natural state before flipping it over.

You're right on the motors wearing - this is definitely outside their design envelope. Having said that, they're not experiencing much torque and I'm going to crack one open to see if I can grease it to give it more life.
JasonStonier
Posts: 19
Joined: 16 Nov 2021, 06:29
E-book readers owned: Kindle Paperwhite
Number of books owned: 2000
Country: UK

Re: Lego Mindstorms scanner - A novel way of scanning magazines

Post by JasonStonier »

Been a few weeks running this one, and I've scanned a couple of hundred magazines now without too many problems - no big errors, and the only real issue is failing to pick up pages when the magazine is un-read - just too much sticktion in the pages. To combat that, I leaf through the magazine before scanning and that helps.

So, I'm calling this design a winner :D

https://www.youtube.com/watch?v=UfI6VLClOUA
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