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

Foot-Operated 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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jlev
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Foot-Operated Scanner

Post by jlev » 04 Jul 2010, 02:28

Hello, everyone. I'd like to share my scanner build, which combines Rob's ideas about using an axle (http://www.diybookscanner.org/forum/vie ... =pvc#p3598) with the Internet Archive's Scribe Scanner (http://www.diybookscanner.org/forum/vie ... ribe#p3611). I wanted to use a design with a foot pedal on the assumption that it would be easier to use over hours of scanning. While the finished product takes up about a foot more space than other, vertical, designs seen on this site, it works quite well. Here it is:
DSC00072.jpeg
Full view of scanner
DSC00072.jpeg (96.47 KiB) Viewed 6498 times
DSC00060.jpeg
Front view of scanner
DSC00060.jpeg (77.8 KiB) Viewed 6498 times
The entire assembly was constructed using found wood and parts from the local hardware store, totaling approximately $200, not including the cameras (a Canon 7.1 mp PowerShot A620 that I already had and a Powershot A560 that I found for $26(!) on eBay). I found all of the electronics on eBay and Craigslist, bringing the total cost down a bit. I think that I could bring the cost down a bit more if I ever re-built the scanner, now that I know what I'm doing.

The axle is made of 1” pvc nipples attached on both sides to 1” T-shaped PVC couplers. The axle is held to two 3/4” steel poles by aluminum straps bolted to the poles. The axle is held in place on one side by the T-shape of the PVC couplers, and on the other by a hex nut that is larger than the straps.
DSC00067.jpeg
Axle
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The platen loosely follows Nalfonso's (http://www.diybookscanner.org/forum/vie ... ?f=1&t=103) and Ann and Chris's (http://www.diybookscanner.org/forum/vie ... ?f=1&t=186) designs. I found a large aluminum frame at the local Goodwill, sawed it in half, and put the two halves together at a 90 degree angle using two corner braces loosely screwed into the frame. I stabilized this part of the platen by affixing two flat corner braces to the outsides of the frame with velcro. The frame is thus able to be disassembled but stays together well.
DSC00061.jpeg
Close-up of platen
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I'm using double-strength glass held in place using the pressure mounts that came with the frame.
DSC00062.jpeg
Rear of platen -- glass is held in place by the pressure of bent U-shaped plates
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The width of the glass is slightly less than that of the frame, allowing the glass to be retracted from the center to scan spiral notebooks. The platen is joined to the arms of the lever using T-shaped mending plates. I drilled directly through the frame (choosing not to reinforce the frame first, as was done in Nalfonso's design) and bent the T plates with pliers (I note this because I was originally worried that I would need something more heavy-duty to bend the plates). The T-plates each then connect to two straight mending plates, one additional brace, and another T-shaped plate bent at 45 degrees. This last T-shaped plate is then connected to the PVC arm.
DSC00063.jpeg
Platen attachment and camera mount
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The Cameras are connected directly to this assembly and are at the distance necessary to get the whole frame in-shot. This also means that the cameras' positions never need to be adjusted.
DSC00068.jpeg
Lever arms
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The electronics follow the plans here: http://www.sakeoftruth.com/2010/04/usb- ... roject-pt- As things are now, I hold the remote in my hand as I scan a book, but eventually I might create a footswitch using, e.g., a pedal made for switching guitar amplifier channels.

Lighting is provided by two Ikea desk lamps with 1700 lumen compact fluorescent bulbs that I found for $0.50 each at a Chinese discount store here in San Francisco. I originally tried using a halogen 100w bulb, but after realizing that it put out 1000 lumens, I started using the compacts, which also don't put out much heat.

Following Mr. Reetz' plans for the New Standard Scanner (http://www.diybookscanner.org/forum/vie ... t=20#p3218), the width of the book cradle is adjustable. To allow for disassembly, the parts of the cradle that come into contact with the book are attached to the rest by velcro. The entire cradle sits on top of a single drawer slide, which allows lateral movement.
DSC00064.jpeg
Cradle design
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The entire assembly sits on a collapsible TV dinner tray that I found at the local Goodwill. Any desk with an open back will work, though. As in the Internet Archive's Scribe scanner, a long foot-operated lever is connected (using high-strength nylon cord) to the back of the scanner.
DSC00065.jpeg
Foot pedal
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As can be seen here, I also attached a series of pulley wheels to the base of the scanner so that, if I ever need to place the scanner on a table/desk without an open back, I can route the cord from the back of the assembly to the front, and have the footpedal right below my chair.
DSC00066.jpeg
Pullies (in case the pedal has to be placed in front of a desk that lacks an open back)
DSC00066.jpeg (75.86 KiB) Viewed 6498 times
I built this scanner as a recent college graduate with very few tools of my own. For any other students like me out there, then, I want to write that this plan only required basic hand-tools, a hacksaw for the PVC, a soldering iron, and an electric drill. As silly as it may sound to more experienced members here, the local ACE Hardware cut all of the wood (which I found next to various garbage cans around the City) for me for between $0.25 and $1.00 per cut. It was worth it to me to pay for the cuts because a) I don't have a saw, and b) I don't have the training to use one safely. I write this because much of my planning for this project dealt with the simple logistics of how to get the pieces without having the tools.

StevePoling
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Re: Foot-Operated Scanner

Post by StevePoling » 04 Jul 2010, 17:28

an impressive accomplishment. particularly your extensive use of recycled/repurposed materials and getting past your lack of proper tools.

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jck57
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Re: Foot-Operated Scanner

Post by jck57 » 04 Jul 2010, 18:02

I really like the aluminum picture frame for the platen holder. Orienting the frame as you have done, with the extruded track facing up, offers many mounting and gusseting possibilities. I'm guessing square nuts could be slid inside the extruded frame in order to fasten braces, lights, or camera mounts anywhere along the frame edge.

Good tip on getting the hardware store to cut material for a nominal fee. Lumber yards will also accommodate.

Well done on elegant problem solving working within budget and tool limits.

benjamin
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Re: Foot-Operated Scanner

Post by benjamin » 04 Jul 2010, 18:40

This is fantastic. I'd assumed the Archive.org machine was using servos. Hope you post video eventually, would like to see that axle motion in action!

As a person with substantial formal training & personal experience w/ woodworking tools, very much appreciate your reasoned & logical approach; however should you ever decide to take the next step down that path at some point, don't overlook basic hand tools... a hand saw + couple of clamps will run you around $12 and the only safety rule to remember is "keep your fingers away from the sharp part." :)

univurshul
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Re: Foot-Operated Scanner

Post by univurshul » 05 Jul 2010, 00:28

This is slick; demonstrates some skills by visualizing PVC, iron, wood, metal without having a dedicated workshop. Nice work.

Average pages scanned/minute?

jlev
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Re: Foot-Operated Scanner

Post by jlev » 05 Jul 2010, 03:37

Thank you all for your kind comments. Benjamin, thanks for the advice about starting small with handtools. I'll do just that for future projects. This project has been an incredibly educating experience, and I look forward to learning more as time goes on.

Here is a video demo of the scanner in action:
ScannerDemo.zip
One-minute scanner demo.
(4.49 MiB) Downloaded 324 times
Please note a few things: a) the lights are a bit off from where they would normally be because the camera I used to record (which usually would be taking shots of the left-hand pages) was being overloaded by the lights in their normal positions; and b) the scanner has an annoying squeak that comes from me failing to get the strap that holds the axle to the left pole perfectly perpendicular to the axle. This causes the nut on the axle to rub against the strap occasionally. I intend to fix it soon.

Univurshul, I scanned a book for 60 seconds in the video and captured 15 shots or 30 pages. At that rate, an hour of constant scanning would yield 1800 pages. I doubt that I could keep up scanning for a full hour, but I haven't found that the scanner produces any fatigue so far -- as long as the foot-pedal is at a comfortable angle, it's not uncomfortable to operate the scanner for extended periods of time.

Here is a shot taken from one of the cameras (the shot is a bit underexposed because the lights were in the wrong position, as mentioned above). I had to downsample the shot quite a bit to post it here.
IMG_0002.jpg
Sample image from scanner (posted here only to be used for educational purposes...)
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The camera was not zoomed at all when the picture was taken (you can see the edges of the aluminum frame). Usually, I use a batch photo editor called Phatch in Linux to crop the frame out of the photos, and then send the photos to ScanTailor (which is an incredible program -- thanks very much to Tulon!)

(I hope that it's all right to post the photo -- if not, please let me know, and I'll take it down)

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daniel_reetz
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Re: Foot-Operated Scanner

Post by daniel_reetz » 05 Jul 2010, 04:02

jlev, your treadle scanner has made my day about 5 times now. Congrats on a great scanner! It's really reminiscent of the Internet Archive scanners, but incorporates a lot of new ideas.

I think I need a treadle scanner... maybe for my next build. I had spent a lot of time needlessly worrying about how to get the platen to travel far enough, but you've shown the most obvious way -- make the pedal long.

benjamin
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Re: Foot-Operated Scanner

Post by benjamin » 06 Jul 2010, 22:49

Terrific. For others looking at the video on Windows, adding an .mov file extension let me open it in VLC.

I hadn't realized the cameras were also moving... have you had any issues with them "wandering," or do they stay in their positions pretty easily?

Obviously the classy way to get rid of the squeak is to fix whatever's causing it, but if you're lazy like me, graphite lube is pretty great for smoothing out wood contacting wood (or anything else); while lithium grease works nicely on metal + metal.

Dan- I have half a notebook full of sketches for alternative pulley &/or lever designs, some foot pedals & some that just reduce the range of motion for platen action... now if only I had some way to like, capture the pages of that notebook and digitize them... (half-kidding. My next project will be a personal-use scanner, but actually the delay is trying to figure out what I'm contractually allowed to publish now that I'm not with the job that introduced me to you lunatics).

jlev
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Re: Foot-Operated Scanner

Post by jlev » 08 Jul 2010, 02:49

Benjamin, thanks for figuring out the .mov extension. I'm working in Linux and hadn't realized that the video wouldn't be immediately viewable on other systems.

I've had no problems at all thus far with wandering cameras. I keep both cameras attached to the scanner as tightly as possible without stripping their mounts. The only camera oddity is that, as can been seen in the sample picture that I posted above, the shots do come out a bit crooked (i.e., not keystoned, but rather not totally square to the book being scanned) because the mending plates that I used to attach the platen to the levers had pre-cut holes in them that didn't exactly line up (this feature of the mending plates can be seen above in the picture labeled "DSC00068.jpeg." This crookedness, however, is corrected automatically in ScanTailor and hasn't been a problem for me, either.

Mr. Reetz, thank you very much for your kind comments. I think that it's important to note that making the pedal long doesn't add anything to the footprint (ho ho) of the whole scanner, which is larger/deeper than other designs anyway due to the added length of the rear (effort) arms of the levers. A long pedal would be a problem with this design, however, if the scanner were set atop a desk that lacked an open back (making the pedal unable to be placed under the scanner). I would be quite interested to see Benjamin's alternate designs to correct that.

Now to find some grease...

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