my sheet metal, weld-less, archivist derivitave

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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rolling29
Posts: 10
Joined: 18 Oct 2015, 10:57
E-book readers owned: nook, nook simple
Number of books owned: 600
Country: USA

my sheet metal, weld-less, archivist derivitave

Post by rolling29 »

Ok, I'll start by saying that I'm not done yet. I've enjoyed reading many, many build threads here and one thing I enjoy most is an unfolding story. Here's my go at being a good story teller...

My history of book scanning, in summary, is hand-held camera/cell phone -> cardboard box cradle -> then with a hand-held picture frame platen -> this. My investment has been pretty minimal, and even though it may not look that way when you see the pictures later, it still is.

Here's the background on my build goals:
-The Archivist is great already. Just copying it isn't as much fun as experimenting.
-Baltic Birch is great, but not what I have readily available.
-Storage ability. In order to pass the "Wife Test" my hobbies must be no bigger than a large suitcase in a closet when not in use.
-I've been using CHDK with SpreadPi on my cardboard box, and I'd like to keep using the same workflow.
-Make it not require welding so more people have the opportunity to use the design files.
-Make it not require complicated sheet metal equipment, same reason. (Like the Archivist, "get a local CNC shop to cut the plywood", this design is "get a local CNC shop to cut the sheet metal, and do a few simple bends too if possible".)

I plan to release all design files to the public domain, after I correct a few mistakes. For now y'all will have to be content with just a few jpgs. ;)

The scan area is Archivist-based, 15"x12" for each page. The layout is based on a 106 degree platen. Why 106? I made a bunch of sketches tracing primary and secondary reflection vectors. 106 gave me the best angular separation between the lens axis and the plotted light source reflections. Maybe it's optimal, maybe it's not. I'm pretty confident that either way it'll work better than my cardboard box scanner. :D

This design is based on 2mm (0.080") aluminum. It all fits in a 4'x10' sheet, which a buddy who owes me a favor had laying around. At current prices these sheets cost a little under $50. He also has a CNC plasma cutting table. (Yes, laser cuts cleaner, but it's hard to beat a cost value ratio based on free.) Part of the favor was shop time, and I got to be the CNC operator. My responsibilities included opening the file and hitting the green button. The machine took about 30 minutes to cut everything and I took about 15 minutes clearing off the parts and scrap. After another 30 minutes removing the sharp edges I got to use a manual brake. It's not all that complicated, but not being a power tool it required lifting a roughly 50 pound handle for [I can't remember how many times] over nearly 2 hours. That was it. About 3 hours from start to pile of raw bent parts. You could also get the CNC guy to cut a dashed line on the bend lines and then it can be bent by hand. It'll be a little less strong, but still pretty good. If any of y'all want to get a shop to cut a set of parts for you, it's good to know that they will put 3 hours into it at most and the price ought to be in line with that.

Because of wanting to avoid welding, the construction method is nuts and bolts. These nuts are mostly stuck to the sheet metal, kind of like a rivet. In some places I made a sandwich of metal and plastic washers with a lock nut. That lets you make a "sticky" but still pretty easily movable joint, like I used in the cradle panels. More on that later. For now I'll admit to spending about an hour installing all the rivet-type nuts, which includes drilling some of the holes to a more precise size than the plasma can accurately melt away.

So, if you don't count design time, I'm at about 4 hours into my build so far. I decided to go ahead and build it anyway even though I know I'll probably have to disassemble it again to paint any parts that need to be black. I admit I can be impatient at times, and I can accept that.

I imagine you, my reader, are getting impatient right about now too. When will I get to the pictures already, right? Ok...
IMAG0005.jpg
That is "storage mode". The lighting "hat" is removed, flipped upside down, and dropped down into the image box. (The main 7-sided box.) The legs fold up and tuck underneath to enclose the cradle. The cradle is also tucked up under the platen glass, and the intent is that the neoprene book bed will protect the glass.
IMAG0003.jpg
Here's a view up into the lighting hat. I'm using standard GU10 sockets and 10W LED bulbs. The electrical plan is a simple parallel circuit and switched lamp cord. With a total of 40W on 120v AC, that's pretty much what a lamp cord is designed for so it seems safe enough to me.
IMAG0002.jpg
And there it is all setup in "go mode". Well, at least so far. My list of things to do is still pretty long. And I have some more parts in the garage that aren't shown yet. Camera mounts, the cradle lift counter-weight stuff, etc. The holidays with extended family will probably soak up most of my free time until January, so that's my excuse for the suspense.

I'm happy to try and answer any questions if I can. If you want to know why I picked some particular design detail the answer is most likely just "well, because I wanted to".

Happy holidays and keep scanning!
duerig
Posts: 388
Joined: 01 Jun 2014, 17:04
Number of books owned: 1000
Country: United States of America

Re: my sheet metal, weld-less, archivist derivitave

Post by duerig »

That is beautiful. I keep thinking that it will climb off the table and rampage through the countryside. :-)

The only thing I'm wondering about is how you will handle glare. Are you planning on powder coating or dulling the metal? Or is an individual reflection not really a problem in practice when everything is reflective?

Keep posting pictures as you perfect this and run some scans, please.

-D
recaptcha
Posts: 64
Joined: 03 Sep 2010, 13:23
Number of books owned: 0
Location: Calgary, Alberta, Canada

Re: my sheet metal, weld-less, archivist derivitave

Post by recaptcha »

Agreed, this looks beautiful. The platen could always be painted a dark color. Does the light hat really need to be so tall? :-)

Duerig, would it be possible to offer an aluminum-based version of The Archivist? Perhaps a bit smaller than the current wood version, and based on rolling29's or other design?
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